S T U . . SLOVAK UNIVERSITY OF TECHNOLOGY IN BRATISLAVA ...... FACULTY OF ARCHITECTURE F C H P T DEPARTMANT OF INTERIOR ......

REPORT ON TRAINING VISIT ABOUT THE SOBJECT OF

DESIGN AND DETERMINATION OF QIBLA DIRACTION DEGREE IN MOSQUE BUILDING FOR AFGHANISTAN AND OTHER COUNTRY OF THE WORLD AND

USEOF THE RENEWABLE ENERGY FOR AFGHANISTAN

IN THE FRAME WORK OF THE PROJET NO.14/12/2011 SAMRS DEVELOPMENT OF HUMAN RESORCE CAPACITY OF KABUL POLYTECHNIC UNIVERSITY FUNDED BY SLOVAK AID

BRATISLAVA 2011 ASSO.PRO.DIP.ING. RAZ .M.AZIZI

1 Acknowledgement:

The author would like to express his appreciation for the Scientific Training Program of architecture at Department of interior at the faculty of architecture of the Slovak Technology University and Slovak Aid program for financial support of this project.

Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art. Historical civilizations are often identified with their surviving architectural achievements.

"Architecture" can mean:

• The art and science of design and erecting buildings and other physical structures. • A general term to describe buildings and other infrastructures. • A style and method of design and construction of buildings and other physical structures. • The practice of an architect, where architecture means to offer or render professional services in connection with the design and construction of a building, or group of buildings and the space within the site surrounding the buildings, that have as their principal purpose human occupancy or use.[1] • Design activity, from the macro-level (urban design, landscape architecture) to the micro-level (construction details and furniture). • The term "architecture" has been adopted to describe the activity of designing any kind of system, and is commonly used in describing information technology.

In relation to buildings, architecture has to do with the planning, designing and constructing form, space and ambience that reflect functional, technical, social, environmental, and aesthetic considerations. It requires the creative manipulation and coordination of material, technology, light and shadow. Architecture also encompasses the pragmatic aspects of realizing buildings and structures, including scheduling, cost estimating and construction administration. As documentation produced by architects, typically drawings, plans and technical specifications, architecture defines the structure and/or behavior of a building or any other kind of system that is to be or has been constructed.

A good architects is that have anice imagation and to create about the architects objects . this tow factors can make by increasing insight of the social and nature

2 of the world . therefore the architect that have how mach more information abaut the world and its enviroment ; connection between the people , social and nature , he can imagine and create nice about the architects effects . thereby this program is very good for advance and improvment of knowledg of architects , and i suggest for more devlopment and distansion of this agreement.

I would like to say my hearth thank to dears Prof. Ing . Arch ,Veronika Kotradys phD ; Prof .Ing . Arch. Stanislav Majcher. PhD. Professors of the interior department of architecture faculty and Prof. Ing . Roman Rabensefer PhD; Prof.Ing. Monika Pavcekova; Prof. Ing. Lucia Moikona Professors of civil engineering faculty for there guidance and assistance during the all time of my training visit. My thank belongs also to dear Assoc. Prof. Ing. Juma Hadary phD , the coordinator of the project SMARS14/12/2011 in the frame work of which my visit was realized . I wish a good health and prosperity live for them.

With best respect Raz Mohammad Azizi

3 Preface

I am, Assoc. prof . Dipl . Ing . Raz Mohammad Azizi came at 1st of Octobers 2011 from Kabul , Afghanistan to Bratislava , Slovakia for training and scientific research . This program was organized in the project work for development the human resource capacity of engineering education in Afghanistan . the project was coordinated by the Slovakia university of technology in Bratislava for Kabul polytechnic university teachers .

This scientific report was prepared during my stay from 1st of October 2011 to 14th December 2011 at the department of interior of architecture faculty of Bratislava Technology University.

This report prepares at tow Basic subjects: 1- Report about architecture (determination of qibla side according to location of the country for all world country). 2- Report about physic in building (heat in building , light in building and acoustic). This report has four following parts: Part 1 : academic and scientific activities(pedagogic). Part 2 : Researches Part 3 : practical activities Part 4 : see for oneself of Bratislava (Acquaintance with Bratislava)

Each part is described as following :

1- academic and scientific activities (pedagogic): I attended to the lectures of the professors and saw the methods of the lectures and teachings, also I visit the classes and saw the students activities, besides of these I also participated to the conferences and seminars presented by the professors and students.

2- Researches:

I researched about two important subjects, that’s the 1st is the determination of qibla side according to the location of the mosque on the country for all worlds its derivatives that are the very important factor for design of the mosque buildings, because The Qibla is the direction that Muslims turn to in their prayers — is toward the Kaaba and symbolizes unity in worshiping one Allah (God). Therefore who’s designed the mosque buildings he or she has to know the qibla side. And the second subject is use of the renewable energy in Afghanistan that is the most important factor and skeleton for economical

4 development of a human being society and a country and especially in our country that it is the important point now a days .

3 – Practical activities

I saw and informed about the laboratory of determination of heat insulation parameters of construction material, determination of light parameters in buildings and acoustic problems in buildings and I saw the instruments of the construction physic laboratory. These activities were done with the prof.Ing.Roman Rabensefer PhD. Professor of civil engineering faculty and aspirant of the laboratory of the engineering faculty.

4- See for oneself of Bratislava (Acquaintance with Bratislava)

See for oneself of Bratislava city and its surrounding villages was very useful for me because I saw there the deferent design and type of buildings; location of the deferent zone of the city ; design of the roads and streets; to be erected of park ; to be builds of bridges ; to construction of street on deferent floors ; territorial prepare for rayon and city used ;to build the deferent type of drain and the deferent type of transportation and there supplies and spatially the Bratislava beautiful nature full of the rivers and the forest . There are very important and helpful for my knowledge development for the subject of(Engineering build of territory and transportation).

5

CONTENT

TITELE PAGE

ACKNOWLEDMENT 2 - 3 PERFACE 4 - 5 WHAT IS A MOSQUE 7 - 10 MASJIDE AL-HARAM 10 - 16 Al – AQSA MOSQUE 17 - 25 Al-MASJED AL-NABAWI 26 - 29 MAZAR-E SHARIF, Afghanistan 30 - 36 QABLA COMPASS 36 - 37 DETERMINATIO OF QIBLA 37 - 39 WHAT IS ENERGY 41 - 43 WHAT ARE THE PRACTICAL SOURCES OF ENERGY 42 - 48 HOW IS ELECTRICITY MADE 48 - 49 WHAT IS RENEWABLE ENERGY 49 - 51 ENERGY EFFICIENCY AND RENEWABLE ENERGY 51 - 57 SOLAR ENERGY 57 - 62 WIND ENERGY 62 - 84 RESUORCES 84 – 86 REFERENCES 86 - 89

6

PART I

DETERMINATION OF QIBLA SIDE FOR THE MOSQUE BUILDIN

7 What is a Mosque?

______A mosque is the building in which Muslims worship God. Throughout Islamic history, the mosque was the centre of the community and towns formed around this pivotal building. Nowadays, especially in Muslim countries mosques are found on nearly every street corner, making it a simple matter for Muslims to attend the five daily prayers. In the West mosques are integral parts of Islamic centers that also contain teaching and community facilities. Mosques come in all shapes and sizes; they differ from region to region based on the density of the Muslim population in a certain area. Muslims in the past and even today have made use of local artisans and architects to create beautiful, magnificent mosques. There are however, certain features that are common to all mosques. Every mosque has a mihrab, a niche in the wall that indicates the direction of Mecca; the direction towards which Muslims pray. Most mosques have a minbar (or pulpit) from which an Islamic scholar is able to deliver a sermon or speech. Other common features include, minarets, tall towers used to call the congregation to prayer. Minarets are highly visible and are closely identified with mosques. Normally there is a large rectangular or square prayer area. It often takes the form of a flat roof supported by columns or a system of horizontal beams supported by architraves. In other common mosque designs, the roof consists of a single large dome on pendentives.[1] There are usually separate prayer areas, with separate entrances for both men and women. Mosques have developed significantly over the past 1400 years. Many have courtyards containing decorative pools and fountains, which originally supplied water for ablution before prayer. Nowadays however, more private bathroom and toilet facilities are provided. Originally simple structures with earthen floors, now, mosque floors are usually covered with plush carpet. They are more often than not decorated with straight lines of geometric designs that ensure Muslims stand in straight rows to perform their five daily prayers. There are never any images of life or statues in mosques, for in Islam it is forbidden that such things are kept or displayed. . At times, the interior walls of the mosque are decorated with verses from the Quran in Arabic calligraphy, or with intricate geometric designs. The patterns are made from a variety of materials including mosaics, stucco, stone, ceramics, and wood. The more classical designs are referred to as arabesque, and they take the form of a radial grid in which circle and star shapes are prominent. Designs can be both two, and three-dimensional. More often than not, even in arid desert countries mosques are cool, serene havens. When a person enters a mosque he or she would have left the hustle and bustle of the material world and retreated into a calm shelter or sanctuary. Mosques are houses of worship. Men are expected to pray all five daily

8 obligatory prayers in a mosque, in congregation. Although women are welcome to pray in the mosque it is more praiseworthy for them to pray in their homes. Nonetheless, Muslims are permitted to pray anywhere, excluding filthy or impure places such as toilets or in graveyards.Prophet Muhammad, may the mercy and blessings of God be upon him, said, “The entire earth was made a masjid for me”[2]. Masjid is the Arabic word for mosque. However, while the term mosque has come to mean a building specifically for prayer the word masjid has retained several layers of meaning. In the very literal sense, masjid means place of prostration. The Arabic word comes from the root “sa-ja-da” meaning to prostrate. When a Muslim’s forehead touches the ground, he or she is close to God. Prayer establishes the connection between the believer and his Lord and prostration symbolises complete submission. Many people have incorrectly stated that the word mosque is not a translation of the word masjid. They claim that the word mosque comes from the word mosquito and attribute it to Queen Isabella and King Ferdinand of 15th century Spain. However, the words mosque and mosquito are totally unrelated. The word “mosque” was introduced into the English language in the late 14th or early 15th century from the French. It comes from the French word mosquée from the old French word mousquaie. The French, in turn, derived the word from the Italian word moschea from moscheta. The Italians got it either directly from the Arabic word masjid or from the old Spanish mesquita.[3] Thus we can see that the translation of the Arabic word Masjid, into English becomes mosque. A mosque is a house of prayer, and a place of prostration. It is a building designed and built specifically for the worship of Allah. It is where Muslims stand shoulder to shoulder, united in their love for God and their desire to please Him.

A mosque is a Muslim place of worship, where the faithful gather to pray, participate in community events, and to exchange information with each other. Mosques in a wide range of architectural styles can be found in nations all over the world, including the Masjid al-Haram in Mecca, one of the most sacred mosques in Islam, and the stunning Blue Mosque in Turkey, which was built by Sultan Ahmed I in Istanbul.

A few architectural features are common to all mosques, regardless as to whether they are built in the form of Chinese pagodas or modernist edifices. A mosque always includes a mihrab, a niche in the wall which faces Mecca. The mihrab is used to orient the congregation as prayers are said, and it is often ornately decorated. Many mosques also have a minibar, a pulpit, along with minarets, tall slender towers which are used to issue the call to prayer.

Most mosques also have a large common area which is designed to accommodate the congregation when they gather for prayers, and mosques have separate areas for men and

9 women so that they can pray in peace. Commonly, a mosque also has community facilities, allowing people to use the mosque for festivals, community meetings, dinners, and other social events. Much like religious buildings in other traditions, the mosque is the hub of community life.

Masjid al-Haram

Coordinates: 21°25′19″N 39°49′34″E / 21.422°N 39.826°ECoordinates: 21°25′19″N 39°49′34″E / 21.422°N 39.826°E Location Makkah, Saudi Arabia Established 638 Branch/tradition Sunni – Salafi Saudi Arabian Administration government Imam(s): Leadership Abdul Rahman Al-Sudais Saud Al-Shuraim Architectural information 900,000 (increased to Capacity 4,000,000 during the hajj

10 period) Minaret(s) 9 Minaret height 89 m (292 ft)

"The Sacred Mosque") is the largest mosque in the world. Located in the city of Mecca (Makkah), it surrounds the Kaaba, the place which Muslims worldwide turn towards while performing daily prayers and is Islam's holiest place. The mosque is also known as the Grand Mosque.[1] The current structure covers an area of 356,800 square metres (88.2 acres) including the outdoor and indoor praying spaces and can accommodate up to four million Muslim worshipers during the Hajj period, one of the largest annual gatherings of people in the world.

History

Islamic tradition holds that the Mosque was first built by the angels before the creation of mankind, when God ordained a place of worship on Earth to reflect The" ,رومعملا تيبلا :the house in heaven called al-Baytu l-Ma'mur (Arabic Worship Place of Angels"). From time to time, the Mosque was damaged by a storm (flood) and was rebuilt anew. According to Islamic belief it was rebuilt by Ibrahim, with the help of his son Ismail. They were ordered by God to build the mosque, and the Kaaba. The Black Stone (Hajar-ul-aswad) is situated on the lower side of the eastern corner of the Kaaba, believed to be the only remnant of the original structure made by Ibrahim. The Kaaba is the direction for all the Muslims to pray across the globe thus signifying unity among all. The Islamic teaching specifically mentions that nothing is miraculous about the Grand Mosque except for the oasis Zamzam which has purportedly never dried ever since it was revealed.

And when We assigned to Ibrahim the place of the House (Kaaba), saying: Do not associate with Me aught, and purify My House for those who make the circuit and stand to pray and bow and prostrate themselves. And when We made the House a resort for men and a place of security. And: Take ye the place of Abraham for a place of prayer. And We enjoined Ibrahim and Ismael, saying: Purify my House for those who visit it and those who abide in it for devotion and those who bow down and those who prostrate themselves. —Qur'an, [Quran 2:125] And when Ibrahim and Ismael raised the foundations of the House (Kaaba): Our Lord! accept from us; surely Thou art the Hearing, the Knowing. —Qur'an, [Quran 2:127]

11 Muslim belief places the story of Ismael and his mother's search for water in the general vicinity of the mosque. In the story, Hagar runs between the hills of Safa and Marwah looking for water for her infant son, until God eventually reveals to her the Zamzam Well, from where water continues to flow to this day.

After the Hijra, upon Muhammed's victorious return to Mecca, Muhammad and his son-in-law, Ali ibn Abi Talib, removed all the idols in and around the Kaaba and cleansed it. This began the Islamic rule over the Kaaba, and the building of a mosque around it.

The first major renovation to the Mosque took place in 692. Before this renovation, which included the mosque's outer walls being raised and decoration added to the ceiling, the Mosque was a small open area with the Kaaba at the centre. By the end of the 700s, the Mosque's old wooden columns had been replaced with marble columns and the wings of the prayer hall had been extended on both sides along with the addition of a minaret. The spread of Islam in the Middle East and the influx of pilgrims required an almost complete rebuilding of the site which included adding more marble and three more minarets.

The mosque was renovated in 1570 by Sultan Selim II's private architect and it resulted in the replacement of the flat roof with domes decorated with calligraphy internally and the placement of new support columns. These features (still present at the Mosque) are the oldest surviving parts of the building and are in fact older than the Kaaba itself (discounting the black stone) which is currently in its fourth incarnation made in 1629. The Saudi government acknowledges 1570 as the earliest date for architectural features of the present Mosque.

Following further damaging rain in the 1620s, the Mosque was renovated yet again: a new stone arcade was added, three more minarets were built and the marble flooring was retiled. This was the unaltered state of the Mosque for nearly three centuries.

Saudi Development

Minarets of the Masjid al-Haram

12 The most significant architectural and structural changes came, and continue to come, from the Saudi status of Guardian of the Holy Places and the honorific title of Custodian of the Two Holy Mosques (the other being the Mosque of the Prophet in Medina) been afforded to King Abdul Aziz. Many of the previously mentioned features, particularly the support columns, were destroyed in spite of their historical value. In their place came artificial stone and marble, the ceiling was refurnished and the floor was replaced. The Al-Safa and Al-Marwah, an important part of both Hajj and Umrah, came to be included in the Mosque itself during this time via roofing and enclosement. Also during this first Saudi renovation four minarets were added.

Interior of the Masjid Al Haram in Mecca, Saudi Arabia.

The second Saudi renovations, this time under King Fahd, added a new wing and an outdoor prayer area to the Mosque. The new wing which is also for prayers is accessed through the King Fahd Gate. This extension is considered to have been from 1982-1988.

The third Saudi extension (1988–2005) saw the building of more minarets, the erecting of a King's residence overlooking the Mosque and more prayer area in and around the mosque itself. These developments have taken place simultaneously with those in Arafat, Mina and Muzdalifah. This third extension has also resulted in 18 more gates being built, three domes corresponding in position to each gate and the installation of nearly 500 marble columns. Other modern developments include the addition of heated floors, air conditioning, escalators and a drainage system.

The death of King Fahd means that the Mosque is now undergoing a fourth extension which began in 2007 and is projected to last until 2020. King Abdullah bin Abdul-Aziz plans to increase the capacity of the mosque by 35%

13 from its current maximum capacity of 800,000 with 1,120,000 outside the Mosque.

Right next to the mosque is the Abraj Al Bait Towers which was completed in 2011 and stands as one of the world's tallest buildings.[2]

Controversies on expansion

It has been a strong controversy that, expansion of the city Mecca is causing harm to archaeological sites. Many millennium old buildings has been demolished. Here are some examples[3]:

• The house where the prophet Muhammad was born, has been demolished and turned into a library. • The house of prophet's wife Khadijah, has been demolished and replaced by public toilet.

Religious significance

The importance of the mosque is twofold. It not only serves as the common direction towards which Muslims pray, but is also the main location for pilgrimages.

Pilgrimage Main articles: Hajj and Umrah

Pilgrims circumambulating the Kaaba.

The Haram is the focal point of the Hajj and Umrah pilgrimages[4] that occur in the month of Dhu al-Hijjah in the Islamic calendar and at any time of the year, respectively. The Hajj pilgrimage is one of the Five Pillars of Islam, required of all able-bodied Muslims who can afford the trip. In recent times, about 3 million Muslims perform the Hajj every year.

Some of the rituals performed by pilgrims are symbolic of historical incidents. For example, the episode of Hagar's search for water is emulated by Muslims as they run between the two hills of Safa and Marwah whenever they visit Mecca.

14 The Hajj is associated with the life of the Islamic prophet Muhammad from the 7th century, but the ritual of pilgrimage to Mecca is considered by Muslims to stretch back thousands of years to the time of Ibrahim (Abraham).

is a pilgrimage to Mecca, Saudi ( ﻋﻤﺮة :Unlike Hajj, the Umrah or (Arabic Arabia, performed by Muslims that can be undertaken at any time of the year.

Kaaba

The Kaaba at Masjid al-Haram Main article: Kaaba

Literally, Kaaba in Arabic means square house. The word Kaaba may also be derivative of a word meaning a cube. Some of these other names include:

• Al-Bait ul Ateeq which, according to one interpretation, means the earliest and ancient. According to another interpretation, it means independent and liberating. • Al-Bayt ul Haram which may be translated as the honorable or holy house.

The whole building is constructed out of the layers of grey blue stone from the hills surrounding Mecca. The four corners roughly face the four points of the compass. In the eastern corner is the Hajr-al-Aswad (the Black Stone), at the northern corner lies the Rukn-al-Iraqi (The Iraqi corner), at the west lies Rukn- al-Shami (The Levantine corner) and at the south Rukn-al-Yamani (The Yemeni corner). The four walls are covered with a curtain (Kiswah). The Kiswa is usually of black brocade with the Shahada outlined in the weave of the fabric. About three quarters of the way up runs a gold embroidered band covered with Qur'anic text.

Qibla Main article: Qibla

15

Masjid al-Haram, Mecca at night

The Qibla—the direction that Muslims turn to in their prayers (salah)—is toward the Kaaba and symbolizes unity in worshiping one Allah (God). At one point the direction of the Qibla was toward Bayt al-Maqdis (Jerusalem) (and is therefore called the First of the Two Qiblas),[citation needed] however, this only lasted for seventeen months, after which the Qibla became oriented towards the Kaaba in Mecca. According to accounts from Muhammad's companions, the change happened very suddenly during the noon prayer at Medina in the Masjid al-Qiblatain. Al-Aqsa Mosque

Coordinates: 31°46′34″N 35°14′09″E / 31.77617°N 35.23583°ECoordinates: 31°46′34″N 35°14′09″E / 31.77617°N 35.23583°E Old City, Location Jerusalem Established 705 CE Branch/tradition Sunni Administration Waqf

16 Imam(s): Muhammad

Leadership Ahmad Hussein Ekrima Sa'id Sabri Architectural information Early Islamic, Style Mamluk Capacity 5,000+ 2 large + tens of Dome(s) smaller ones Minaret(s) 4 37 meters Minaret height (121 ft) (tallest) Limestone First qibla (external walls, minaret, facade) stalactite (minaret), Gold, Materials lead and stone(domes), white marble (interior columns) and mosaic [1]

Interior view of the mosque showing the mihrab, indicating the qibla

The historical significance of the al-Aqsa Mosque in Islam is further emphasized by the fact that Muslims turned towards al-Aqsa when they prayed for a period of sixteen or seventeen months after migration to Medina in 624, thus it became the qibla ("direction") that Muslims faced for prayer.[57] Muhammad later prayed towards the Ka'aba in Mecca after receiving a revelation during a prayer session.[Quran 2:142–151][58] The qibla was relocated to the Ka'aba where Muslims have been directed to pray ever since.[59]

The altering of the qibla was precisely the reason the Rashidun caliph Umar, despite identifying the Rock—which Muhammad used to ascend to Heaven—

17 upon his arrival at the Noble Sanctuary in 638, neither prayed facing it nor built any structure upon it. This was because the significance of that particular spot on the Noble Sanctuary was superseded in Islamic jurisprudence by the Ka'aba in Mecca after the change of the qibla towards that site.[60]

According to early Qur'anic interpreters and what is generally accepted as Islamic tradition, in 638 CE Umar, upon entering a conquered Jerusalem, consulted with Ka'ab al-Ahbar—a Jewish convert to Islam who came with him from Medina—as to where the best spot would be to build a mosque. Al-Ahbar suggested to him that it should be behind the Rock "... so that all of Jerusalem would be before you." Umar replied, "You correspond to Judaism!" Immediately after this conversation, Umar began to clean up the site—which was filled with trash and debris—with his cloak, and other Muslim followers imitated him until the site was clean. Umar then prayed at the spot where it was believed that Muhammad had prayed before his night journey, reciting the Qur'anic sura Sad.[60] Thus, according to this tradition, Umar thereby reconsecrated the site as a mosque.[61]

Because of the holiness of Noble Sanctuary itself—being a place where David and Solomon had prayed—Umar constructed a small prayer house in the southern corner of its platform, taking care to avoid allowing the Rock to come between the mosque and the direction of Ka'aba so that Muslims would face only Mecca when they prayed.[60]

al-Aqsa, is the third holiest site in Sunni Islam and is located in the Old City of Jerusalem. The site on which the silver domed mosque sits, along with the Dome of the Rock, also referred to as al-Haram ash-Sharif or "Noble Sanctuary,"[2] is the Temple Mount, the holiest site in Judaism, the place where the Temple is generally accepted to have stood. Muslims believe that Muhammad was transported from the Sacred Mosque in Mecca to al-Aqsa during the Night Journey. Islamic tradition holds that Muhammad led prayers towards this site until the seventeenth month after the emigration, when God directed him to turn towards the Ka'aba.

The al-Aqsa Mosque is believed by Muslims to have been built in ancient times, 40 years after the construction of the Kaabah.[3][Full citation needed] In the seventh century its walls were renovated by the Rashidun caliph Umar, who also built a small building to the south. A major rebuilding of the Mosque Compound was commissioned by the Ummayad caliph Abd al-Malik, and included the addition of the basement, gates and other structures such as the Dome of the Rock. The work was completed and finished by his son al-Walid in 705 CE. [4] Other ruling dynasties of the Islamic Caliphate also constructed additions within al-Aqsa

18 Mosque’s enclave, such as its dome, facade, its minbar, minarets and the interior structure. When the Crusaders captured Jerusalem in 1099, they used parts of al-Aqsa Mosque as either residences, stables or churches, but its function as a mosque was restored after its recapture by Saladin. More renovations, repairs and additions were undertaken in the later centuries by the Ayyubids, Mamluks, the Supreme Muslim Council, and Jordan. Today, the Old City is under Israeli control, but the mosque remains under the administration of the Palestinian-led Islamic waqf.

Masjid al-Aqsa translates from Arabic into English as "the farthest mosque." The name refers to a chapter of the Qur'an called "The Night Journey" in which it is said that Muhammad traveled from Mecca to "the farthest mosque," and then up to Heaven on a heavenly creature called al-Buraq al-Sharif.[5][6] Until the Ottoman conquest of Jerusalem in the 16th-century, "al-Masjid al-Aqsa" referred not only to the mosque, but to the entire Noble Sanctuary (Temple Mount). The sanctuary complex has since come to be known as al-Haram ash- Sharif, and the mosque itself as al-Jami' al-Aqsa (al-Aqsa Mosque).[7]

Al-Aqsa Mosque as a whole is confused with a particular building within it, also known as al-Jami' al-Aqsa or al-Qibli or Masjid al-Jumah or al-Mughata, these names refer to the southern building with the silver lead dome.

For centuries, al-Masjid al-Aqsa referred not only to the mosque, but to the entire sacred sanctuary. This changed during the period of Ottoman rule (c. early 16th century to 1918) when the sanctuary complex came to be known as al Haram ash-Sharif, and the mosque founded by Umar came to be known as al- Jami' al-Aqsa or al-Aqsa Mosque.[7]

The al-Aqsa Mosque is located on the Temple Mount, referred to by Muslims today as the "Haram al-Sharif" ("The Noble Sanctuary"), an enclosure expanded by King Herod the Great beginning in 20 BCE. The mosque resides on an artificial platform that is supported by arches constructed by Herod's engineers to overcome the difficult topographic conditions resulting from the southward expansion of the enclosure into the Tyropoeon and Kidron valleys. At the time of the Second Temple, the present site of the mosque was occupied by the Royal Stoa, a basilica running the southern wall of the enclosure.[8] The Royal Stoa was destroyed along with the Temple during the sacking of Jerusalem by the Romans in 70 CE. Emperor Justinian built a Christian church on the site in the 530s which was consecrated to the Virgin Mary and named "Church of Our Lady." The church was later destroyed by Khosrau II, the Sassanid emperor, in the early 7th-century and left in ruins.[9]

Analysis of the wooden beams and panels removed from the mosque during renovations in the 1930s shows they are made from Cedar of Lebanon and

19 cypress. Radiocarbon dating indicates a large range of ages, some as old as 9th- century BCE, showing that some of the wood had previously been used in older buildings.[10]

The mosque along the southern wall of the The Noble Sanctuary

It is known that the current construction of the al-Aqsa Mosque is dated to the early Ummayad period of rule in Palestine. Architectural historian K. A. C. Creswell, referring to a testimony by Arculf, a Gallic monk, during his pilgrimage to Palestine in 679–82, notes the possibility that the second caliph of the Rashidun Caliphate, Umar ibn al-Khattab, erected a primitive quadrangular building for a capacity of 3,000 worshipers somewhere on the Haram ash- Sharif. However, Arculf visited Palestine during the reign of Mu'awiyah I, and it is possible that Mu'awiyah ordered the construction, not Umar. This latter claim is explicitly supported by the early Muslim scholar al-Muthahhar bin Tahir.[11]

According to several Muslim scholars, including Mujir ad-Din, al-Suyuti, and al-Muqaddasi, the mosque was reconstructed and expanded by the caliph Abd al-Malik in 690 along with the Dome of the Rock.[11][12] Guy le Strange claims that Abd al-Malik used materials from the destroyed Church of Our Lady to build the mosque and points to possible evidence that substructures on the southeast corners of the mosque are remains of the church.[12] In planning his magnificent project on the Temple Mount, which in effect would turn the entire complex into the Haram al-Sharif ("the Noble Sanctuary"), Abd al-Malik wanted to replace the slipshod structure described by Arculf with a more sheltered structure enclosing the qibla, a necessary element in his grand scheme. However, the entire Haram al-Sharif was meant to represent a mosque. How much he modified the aspect of the earlier building is unknown, but the length of the new building is indicated by the existence of traces of a bridge leading from the Umayyad palace just south of the western part of the complex. The bridge would have spanned the street running just outside the southern wall of the Haram al-Sharif to give direct access to the mosque. Direct access from palace to mosque was a well-known feature in the Umayyad period, as evidenced at various early sites. Abd al-Malik shifted the central axis of the

20 mosque some 40 meters (130 ft) westward, in accord with his overall plan for the Haram al-Sharif. The earlier axis is represented in the structure by the niche still known as the "mihrab of 'Umar." In placing emphasis on the Dome of the Rock, Abd al-Malik had his architects align his new al-Aqsa Mosque according to the position of the Rock, thus shifting the main north–south axis of the Noble Sanctuary, a line running through the Dome of the Chain and the Mihrab of Umar.[13]

In contrast, Creswell, while referring to the Aphrodito Papyri, claims that Abd al-Malik's son, al-Walid I, reconstructed the Aqsa Mosque over a period of six months to a year, using workers from Damascus. Most scholars agree that the mosque's reconstruction was started by Abd al-Malik, but that al-Walid oversaw its completion. In 713–14, a series of earthquakes ravaged Jerusalem, destroying the eastern section of the mosque, which was subsequently rebuilt during al-Walid's rule. In order to finance its reconstruction, al-Walid had gold from the dome of the Rock minted to use as money to purchase the material.[11] The Umayyad-built al-Aqsa Mosque most likely measured 112 x 39 meters.[13]

Architecture

The rectangular al-Aqsa Mosque and its precincts are 144,000 square metres (1,550,000 sq ft), although the mosque itself is about 35,000 square metres (380,000 sq ft) and could hold up to 5,000 worshipers.[34] It is 272 feet (83 m) long, 184 feet (56 m) wide.[34]

Dome

The silver-colored dome consists of lead sheeting

Unlike the Dome of the Rock, which reflects classical Byzantine architecture, the dome of the Al-Aqsa Mosque is characteristic of early Islamic architecture.[35] Nothing remains of the original dome built by Abd al-Malik. The present-day dome was built by az-Zahir and consists of wood plated with lead enamelwork.[11] In 1969, the dome was reconstructed in concrete and covered with anodized aluminum instead of the original ribbed lead enamel

21 work sheeting. In 1983, the aluminum outer covering was replaced with lead to match the original design by az-Zahir.[36]

Al-Aqsa's dome is one of the few domes to be built in front of the mihrab during the Umayyad and Abbasid periods, the others being the Umayyad Mosque in Damascus (715) and the Great Mosque at Sousse (850).[37] The interior of the dome is painted with 14th-century-era decorations. During the 1969 burning, the paintings were assumed to be irreparably lost, but were completely reconstructed using the trateggio technique, a method that uses fine vertical lines to distinguish reconstructed areas from original ones.[36]

Minarets

The mosque has four minarets on the southern, northern and western sides. The first minaret, known as al-Fakhariyya Minaret, was built in 1278 on the southwestern corner of the mosque, on the orders of the Mamluk sultan Lajin. It was named after Fakhr al-Din al-Khalili, the father of Sharif al-Din Abd al- Rahman who supervised the building's construction. It was built in the traditional Syrian style, with a square-shaped base and shaft, divided by moldings into three floors above which two lines of muqarnas decorate the muezzin's balcony. The niche is surrounded by a square chamber that ends in a lead-covered stone dome.[38]

The Ghawanima Minaret, 1900

The second, known as the Ghawanima minaret, was built at the northwestern corner of the Noble Sanctuary in 1297–98 by architect Qadi Sharaf al-Din al- Khalili, also on the orders of the Sultan Lajin. Six stories high, it is the tallest minaret of the Noble Sanctuary.[39] The tower is almost entirely made of stone, apart from a timber canopy over the muezzin's balcony. Because of its firm

22 structure, the Ghawanima minaret has been nearly untouched by earthquakes. The minaret is divided into several stories by stone molding and stalactite galleries. The first two stories are wider and form the base of the tower. The additional four stories are surmounted by a cylindrical drum and a bulbous dome. The stairway is externally located on the first two floors, but becomes an internal spiral structure from the third floor until it reaches the muezzin's balcony.[40]

In 1329, Tankiz—the Mamluk governor of Syria—ordered the construction of a third minaret called the Bab al-Silsila Minaret located on the western border of the al-Aqsa Mosque. This minaret, possibly replacing an earlier Umayyad minaret, is built in the traditional Syrian square tower type and is made entirely out of stone.[41] Since the 16th-century, it has been tradition that the best muezzin ("reciter") of the adhan (the call to prayer), is assigned to this minaret because the first call to each of the five daily prayers is raised from it, giving the signal for the muezzins of mosques throughout Jerusalem to follow suit.[42]

The last and most notable minaret was built in 1367, and is known as Minarat al-Asbat. It is composed of a cylindrical stone shaft (built later by the Ottomans), which springs up from a rectangular Mamluk-built base on top of a triangular transition zone.[43] The shaft narrows above the muezzin's balcony, and is dotted with circular windows, ending with a bulbous dome. The dome was reconstructed after the Jordan Valley earthquake of 1927.[43]

There are no minarets in the eastern portion of the mosque. However, in 2006, King Abdullah II of Jordan announced his intention to build a fifth minaret overlooking the Mount of Olives. The King Hussein Minaret is planned to be the tallest structure in the Old City of Jerusalem.[44][45]

Facade and porch

The facade and porch of the mosque. They were constructed and expanded by the Fatimids, the Crusaders, the Mamluks and the Ayyubids

The facade of the mosque was built in 1065 CE on the instructions of the Fatimid caliph al-Mustansir. It was crowned with a balustrade consisting of

23 arcades and small columns. The Crusaders damaged the facade during their era of rule in Palestine, but it was restored and renovated by the Ayyubids. One addition was the facade's covering with tiles.[14] The second-hand material of the facade's arches includes sculpted ornamental material from taken from Crusader structures in Jerusalem.[46] There are fourteen stone arches along the facade,[5] most of which are of a Romanesque style. The outer arches added by the Mamluks follow the same general design. The entrance to the mosque is through the facade's central arch.[47]

The porch is located at the top of the facade. The central bays of the porch were built by the Knights Templar during the First Crusade, but Saladin's nephew al- Mu'azzam ordered the construction of the porch itself in 1217.[14]

Interior

The al-Aqsa Mosque has seven aisles of hypostyle naves with several additional small halls to the west and east of the southern section of the building.[15] There are 121 stained glass windows in the mosque from the Abbasid and Fatimid eras. About a fourth of them were restored in 1924.[22]

Interior view of the mosque showing the central naves and columns

The mosque's interior is supported by 45 columns, 33 of which are white marble and 12 of stone.[34] The column rows of the central aisles are heavy and stunted. The remaining four rows are better proportioned. The capitals of the columns are of four different kinds: those in the central aisle are heavy and primitively designed, while those under the dome are of the Corinthian order,[34] and made from Italian white marble. The capitals in the eastern aisle are of a heavy basket-shaped design and those east and west of the dome are also basket- shaped, but smaller and better proportioned. The columns and piers are connected by an architectural rave, which consists of beams of roughly squared timber enclosed in a wooden casing.[34]

A great portion of the mosque is covered with whitewash, but the drum of the dome and the walls immediately beneath it are decorated with mosaics and

24 marble. Some paintings by an Italian artist were introduced when repairs were undertaken at the mosque after an earthquake ravaged the mosque in 1927.[34] The ceiling of the mosque was painted with funding by King Farouk of Egypt.[47]

The minbar ("pulpit") of the mosque was built by a craftsman named Akhtarini from Aleppo on the orders of the Zengid sultan Nur ad-Din. It was intended to be a gift for the mosque when Nur ad-Din would capture Jerusalem from the Crusaders and took six years to build (1168–74). Nur ad-Din died and the Crusaders still controlled Jerusalem, but in 1187, Saladin captured the city and the minbar was installed. The structure was made of ivory and carefully crafted wood. Arabic calligraphy, geometrical and floral designs were inscribed in the woodwork.[48] After its destruction by Rohan in 1969, it was replaced by a much simpler minbar. In January 2007, Adnan al-Husayni—head of the Islamic waqf in charge of al-Aqsa—stated that a new minbar would be installed;[49] it was installed in February 2007.[50] The design of the new minbar was drawn by Jamil Badran based on an exact replica of the Saladin Minbar and was finished by Badran within a period of five years.[48] The minbar itself was built in Jordan over a period of four years and the craftsmen used "ancient woodworking methods, joining the pieces with pegs instead of nails, but employed computer images to design the pulpit [minbar]."[49]

[edit] Ablution fountain

The mosque's "al-Kas" ablution fountain

The mosque's main ablution fountain, known as al-Kas ("the Cup"), is located north of the mosque between it and the Dome of the Rock. It is used by worshipers to perform wudu, a ritual washing of the hands, arms, legs, feet, and face before entry into the mosque. It was first built in 709 by the Ummayads, but in 1327–28 Governor Tankiz enlarged it to accommodate more worshipers. Although originally supplied with water from Solomon's Pools near Bethlehem, it currently receives water from pipes connected to Jerusalem's water supply.[51] In the 20th-century, al-Kas was provided taps and stone seating.[52]

25 The Fountain of Qasim Pasha, built by the Ottomans in 1526 and located north of the mosque on the platform of the Dome of the Rock, was used by worshipers for ablution and for drinking until the 1940s. Today, it stands as a monumental structure.[53]

Al-Masjid al-Nabawi

"Mosque of the Prophet"), often called the Prophet's Mosque, is a mosque situated in the city of Medina. As the final resting place of the Prophet Muhammad, it is considered the second holiest site in Islam by Muslims (the first being the Masjid al-Haram in Mecca) and is one of the largest mosques in the world. The mosque is under the control of the Custodian of the Two Holy Mosques. It is the second mosque built in history.

One of the most notable features of the site is the Green Dome over the center of the mosque, where the tomb of Muhammad is located. It is not exactly known when the green dome was constructed but manuscripts dating to the early 12th century describe the dome. It is known as the Dome of the Prophet or the Green Dome.[1] Subsequent Islamic rulers greatly expanded and decorated it. Early Muslim leaders Abu Bakr and Umar are buried in an adjacent area in the mosque.

The site was originally Muhammad's house; he settled there after his Hijra (emigration) to Medina, later building a mosque on the grounds. He himself shared in the heavy work of construction. The original mosque was an open-air building. The basic plan of the building has been adopted in the building of other mosques throughout the world.

The mosque also served as a community center, a court, and a religious school. There was a raised platform for the people who taught the Qur'an. In 1909, it became the first place in the Arabian Peninsula to be provided with electrical lights.[2]

Outside the Prophets Mosque

The original mosque was built by Muhammad next to the house where he settled after his journey to Medina in 622 AD. The original mosque was an open-air building with a raised platform for the reading of the Qur'an. It was a rectangular enclosure of 30 × 35 m (98 × 115 ft), built with palm trunks and mud walls, and accessed through three doors: Bab Rahmah (Door of Mercy) to the south, Bab Jibril (Door of Gabriel) to the west and Bab al- Nisa' (Door of the Women) to the east. The basic plan of the building has since been adopted in the building of other mosques throughout the world.

26 Inside, Muhammad created a shaded area to the south called the suffah and aligned the prayer space facing north towards Jerusalem. When the qibla (prayer direction) was changed to face the Kaaba in Mecca, the mosque was re-oriented to the south. The mosque also served as a community center, a court, and a religious school. Seven years later (629 AD/7 AH), the mosque was doubled in size to accommodate the increasing number of Muslims.

Subsequent Islamic rulers continued to enlarge and embellish the mosque over the centuries. In 707, Umayyad Caliph Al-Walid ibn Abd al-Malik (705-715) replaced the old structure and built a larger one in its place, incorporating the tomb of Muhammad. This mosque was 84 by 100 m (276 by 330 ft) in size, with stone foundations and a teak roof supported on stone columns. The mosque walls were decorated with mosaics by Coptic and Greek craftsmen, similar to those seen in the Umayyad Mosque in Damascus and the Dome of the Rock in Jerusalem (built by the same caliph). The courtyard was surrounded by a gallery on four sides, with four minarets on its corners. A mihrab topped by a small dome was built on the qibla wall.

Abbasid Caliph al-Mahdi (775-785) replaced the northern section of Al-Walid's mosque between 778 and 781 to enlarge it further. He also added 20 doors to the mosque: eight on each of the east and west walls, and four on the north wall.

Green Dome above the tomb of Muhammad

During the reign of the Mamluk Sultan Qalawun, a dome was erected above the tomb of Muhammad and an ablution fountain was built outside of Bab al-Salam (Door of Peace). Sultan Al-Nasir Muhammad rebuilt the fourth minaret that had been destroyed earlier. After a lightning strike destroyed much of the mosque in 1481, Sultan Qaitbay rebuilt the east, west and qibla walls.

The Ottoman sultans who controlled Medina from 1517 until World War I also made their mark. Sultan Suleiman the Magnificent (1520–1566) rebuilt the western and eastern walls of the mosque and built the northeastern minaret known as al-Suleymaniyya. He added a new mihrab (al-Ahnaf) next to Muhammad's mihrab (al-Shafi'iyyah) and placed a new dome covered in lead sheets and painted green above Muhammad's house and tomb.

During the reign of Ottoman Sultan Abdülmecid (1839–1861), the mosque was entirely remodeled with the exception of Muhammad's Tomb, the three mihrabs, the minbar and the

27 Suleymaniyya minaret. The precinct was enlarged to include an ablution area to the north. The prayer hall to the south was doubled in width and covered with small domes equal in size except for domes covering the mihrab area, Bab al-Salam and Muhammad's Tomb. The domes were decorated with Qur'anic verses and lines from Qaṣīda al-Burda (Poem of the Mantle), the famous poem by 13th century Arabic poet Busiri. The qibla wall was covered with glazed tiles featuring Qur'anic calligraphy. The floors of the prayer hall and the courtyard were paved with marble and red stones and a fifth minaret (al-Majidiyya), was built to the west of the enclosure.

After the foundation of the Kingdom of Saudi Arabia in 1932, the mosque underwent several major modifications. In 1951 King Ibn Saud (1932–1953) ordered demolitions around the mosque to make way for new wings to the east and west of the prayer hall, which consisted of concrete columns with pointed arches. Older columns were reinforced with concrete and braced with copper rings at the top. The Suleymaniyya and Majidiyya minarets were replaced by two minarets in Mamluk revival style. Two additional minarets were erected to the northeast and northwest of the mosque. A library was built along the western wall to house historic Qur'ans and other religious texts.

Rear entrance of the Prophets mosque

In 1973 Saudi King Faisal bin Abdul Aziz ordered the construction of temporary shelters to the west of the mosque to accommodate the growing number of worshippers in 1981, the old mosque was surrounded by new prayer areas on these sides, enlarging five times its size.

The latest renovations took place under King Fahd and have greatly increased the size of the mosque, allowing it to hold a large number of worshippers and pilgrims and adding modern comforts like air conditioning. He also installed twenty seven moving domes at the roof of Masjid Nabawi.[3]

28

Tomb of Prophet Muhammad

One of two courtyards inside the mosqu

29

The shrine of Hazrat-e Ali, also called the Blue Mosque, in Mazar-e Sharif, in northern Afghanistan MAZAR-E SHARIF, Afghanistan -- What would Afghanistan look like without war?

It could look like the oasis of peace that is the Blue Mosque standing in its flower-filled park in the center of Mazar-e Sharif.

Afghanistan once attracted thousands of tourists before its decades of war began, and here it is easy to see why.

The block-sized park is surrounded by the noise of a modern city. It is girded on every side by streets with racing traffic, small shops, and sidewalk bazaars filled with crowds.

But as soon as you enter the park, the urban noise recedes. There is the laughter of children and the cooing of doves. Dozens of children with their parents and hundreds, no thousands, of snow white doves waddling across the rose-lined paths, pecking at the ground, and soaring overhead.

The white doves act like they live here and they do. They have been raised by the Blue Mosque's attendants since it was built in the 12th century and they have become one of its famous symbols.

30

Children feed pigeons in the Blue Mosque complex

Legend has it that the doves are pure white because of the sanctity of the mosque itself; if a dove with a speck of color flies in and stays, it too will turn white as snow.

To one side of the mosque complex is the pigeon house. It is a large, low concrete box with small windows and most of its space below ground. This is where the doves nest and breed year-round. It is also where they are fed.

The pigeon caretaker outside the shrine On the building's flat roof, an old man is scattering seed by the tinful, appearing and disappearing in a cloud of white wings.

But it is the Blue Mosque in the center of the park that rivets your attention. It is truly blue, with its sides dressed in thousands of colorful and intricately patterned tiles that shimmer in the sunlight like a mirage. All the paths lead to it, and almost everyone who comes to the park visits it.

31

Well Worn

At the door of the mosque complex, you check your shoes and enter an ancient setting. Between prayers, families stroll the mosque's flagstone court and some visit the mosque's small museum.

There are many pilgrims here, too, who have come from all over Afghanistan and beyond. They visit the shrine of Hazrat Ali, which forms the largest wing of the complex and can only be entered by the faithful.

The shrine houses the tomb of Ali, the cousin and son-in-law of the Prophet Muhammad. People here believe his body was moved to Afghanistan from its original burial place in Al- Najaf, Iraq, sometime early in the history of Islam.

Women in strict Islamic dress enter the Blue Mosque complex. (file photo)

It was a local mullah who discovered Ali's new resting place at the beginning of the 12th century. He had a dream in which Ali appeared to reveal that he had been secretly buried near the ancient city of Balkh, whose ruins still stand some 20 kilometers west of Mazar-e Sharif. The Seljuk sultan of the time, Ahmed Sanjar, ordered a shrine to be built on the location revealed to the mullah and that shrine is today's Blue Mosque.

The shrine itself has had a tumultuous history. It was destroyed by Genghis Khan and his Mongol army in the 13th century. But it was rebuilt and has always been the most significant place of pilgrimage in Afghanistan, both for Shi'ite and Sunni Muslims.

When it is time for prayer, the sound of the muezzin's voice rings out over the mosque complex from one of the four corner minarets.

32

Calling The Faithful

It is possible to meet the muezzin as he leaves his room at the base of the minaret and joins the crowd heading to the prayer hall.

Qari Shir Ahmad Ansari says he has been chanting the call to prayer at the Blue Mosque for 18 years and that his father did so before him. Little has changed over the generations, he adds, apart from adding a loudspeaker system.

In his father's time, four muezzins stood at the top of the minaret and called out in perfect unison, each facing a different direction. Then, just as today, the call could be heard across the center of the city.

Qari Shir Ahmad Ansari, a muezzin at the Blue Mosque He says that muezzins give the Azan, or call to prayer, its true, pure tone by cupping their hands over their ears, as singers do, to hear themselves.

"Based on the Hadith, or the Prophet [Muhammad's] saying, when we chant we raise our hands up to our ears and start the Azan with the phrase 'God is great,'" Ansari says. "The special thing about Azan is that we take ablution [beforehand] and then call the faithful to come pray at a sacred place."

The muezzin hurries off to pray, leaving visitors to admire the tiles that cover the mosque's exterior. There are countless thousands of individual tiles, most about the size of a hand, and each composing a piece of a larger mosaic pattern. The larger patterns themselves vary from one part of the mosque's exterior to another, turning the whole into a swirling, abstract, and almost otherworldly vision.

Constant Upkeep

The sense of otherworldliness is an ancient trick of Islamic architecture. Distracted by the colors and designs of the tiles, the viewer forgets to notice the solid structure of the building itself or think about the physical laws that hold it up. Instead, the building appears weightless, like a miracle hovering on earth.

Where do these beautiful tiles come from? The men who make the tiles have a small

33 workshop just outside the mosque complex. They are surprised to receive visitors but ready to offer tea and answer questions.

"I am Mohammad Shah, head tile maker at the Blue Mosque," one says by way of introduction. "I have been in the business for 24 years. Whenever there is something wrong with the tiles on the walls, or if some visitors pry off some tiles and take them away, we fix the damage."

Chief tile maker Mohammad Shah at his craft

In the workshop, one of Shah's assistants is making clay by pouring water over a mound of earth on the floor and treading on it to get the right consistency. Others are taking dry tiles and tracing patterns on them before they are painted and fired in the kiln. The workshop looks surprisingly busy.

Shah says the Blue Mosque needs constant upkeep. Pilgrims often break small corners off its famous tiles to take home as treasured mementos. But the real damage is from the elements, because there is little money, apart from the pilgrims' donations that support the mosque, to weatherproof the walls as needed.

"This apparatus produces 6 square meters of tile per month," Shah says, as he shows off the workshop's aging kiln. "And all of the six meters square is used; even one tile does not remain unused. This is because the Rawza-e Sharif [the mosque] has been ruined very much;

34 many tiles are damaged and have fallen off. If this tile-producing kiln were not available, the mosque would have turned into a ruined place."

A close-up of Blue Mosque tiles Each damaged tile, he notes, has to be individually duplicated by the artisans. There is a row of broken tiles awaiting replication in the alcove where he and another master tile maker sit. The two masters are teaching their skills to seven apprentices whom they hope will continue preserving the mosque for another generation.

Outside, the Blue Mosque staggers visitors with its beauty. If tiles are missing here and there, it is not what the eye notices.

The tile makers may feel they are in an impossible race to keep up, but the mosque ensemble itself rises above such concerns

Qibla compass

A qibla compass or qiblah compass (sometimes also called qibla/qiblah indicator) is a modified compass used by Muslims to indicate the direction to face to perform ritual parayers. In Islam, this direction is called qibla, and points towards the city of Mecca and specifically to the Ka'abah. While the compass, like any other compass, points north, the direction of prayer is indicated by marks on the perimeter of the dial, corresponding to different cities, or by a second pointer set by the user according to their own location. Al- Biruni wrote his book (Kitab Tahdid al-Amakin, or the demarcation of the coordinates of cities) to determine the qibla.[1] To determine the proper direction, one has to know with some precision both the longitude and latitude of one's own location and those of Mecca, the city toward which one must face. Once that is determined, the values are applied to a

35 spherical triangle, and the angle from the local meridian to the required direction of Mecca can be determined. The problem admits of more than one method of solution, and Al-Biruni did his share in supplying the various methods in this book.[2] Qibla indicators were made after al-Kindi in various forms. The indicator usually comprises a round brass box with a hinged lid and an inset magnetic compass. A list of important Islamic places with their longitudes, latitudes, is inscribed in Arabic on all sides of the box. The compass has a blued steel needle with an open circle to indicate North. It is surmounted by a brass pyramidal pivot and a glass plate covers all. A brass ring over the rim of the compass carries a degree circle numbered in 'abjad' numerals and the cardinal points are marked. The folding triangular gnomon is supported by a decorative open-work motif. The lid of the box is secured by a hook fastener. The instrument serves the user to determine the correct 'qibla' - the direction to which Muslims turn in prayer to face the Ka'ba in Mecca. Ornate qibla compasses date back at least to the 18th century. Some modern versions use digital readout instead of a magnetic pointer.

Some qibla compasses also include a tally counter, used to count the repetition of various du'a said after prayer.

] References

1. ^ MuslimHeritage.com - Topics 2. ^ Saliba G.: Al-Biruni; Dictionary of Middle Ages; Edt Joseph Strayer; Vol 2. Charles Scribner’s Sons, new York. Pp. 248-52; at p.248

36 Easy Way To Determine Qibla Direction for Shalat

Determination of Qibla direction is given the most basic knowledge on astronomy lecture. An understanding of a spherical earth and determining the direction of the earth's surface using a triangular ball is always applied in determining the direction of Qibla. Astronomy as the science of astronomy including the oldest Muslim scientists first developed originally for thepurposes of worship . Determination of direction and timing of concern astronomy, therefore is important in understanding the arguments related syar'i direction and time.

Initially I calculate Qibla direction is considered complicated, therefore only astronomer who can do it. But now, with berkembangkan computers and programming languages, the count is easily made in the form of application program so that everyone can calculate the direction of Qibla. Stay taught how to determine the direction of so many degrees that use the sun compass or shadow. The existence of GPS to determine the coordinates of the place and also function as a compass increasingly provide convenience.

Astronomer provide the easiest alternative. If the Grand Mosque is a very high tower with very bright lights on top so everyone can see it in many countries, then we would be very easy to determine the direction of Qibla. Simply by looking at the lights above the Grand Mosque. Now, astronomer knows no natural light so bright that at certain moments just above Mecca, around the Grand Mosque. That's the sun.

At about the 28th of May and approximately 15/16 July each year at noon at Mecca, the sun was directly overhead. It was then that people in Makkah did not see their own shadow because the sun perpendicular on top of them. But elsewhere in the world could see the sun, there is a shadow object that can be used as a guide direction of Qibla.

At that moment as if we're looking at very bright lights over the Grand Mosque and the imaginary lines we become Haram directions. So, based on the proposition syar'i, hadapkanlah we face when praying in that direction. That is the direction of Qibla. Very, very easy. Staying see the sun and shadow at around 16:18 pm (28 May) or 16:27 pm (15/16 July).

If we want to implement the proposition syar'i QS 2:144, that's when the most appropriate. No need calculation formula triangle ball. No need computer. No need to compass. Simply

37 look at the sun, we are then facing the Grand Mosque. If it is disturbed cloud in the day, plus minus 2 days from that date and plus minus 5 minutes from time was still sufficiently accurate to determine the Qibla direction for relatively slow changes in the position of the sun.

With the development of satellite technology and the internet, we now can determine the qibla direction directly by looking at satellite imagery in the location we want. Site www.qiblalocator.com mark a red line that leads to the temple at the Grand Mosque. If we use a laptop, just spread your laptop screen sesuah direction or road building around us that were recorded on satellite images. Direction is determined by qiblalocator has proved equal to the results of calculations using a ball or a triangle with the sun shadow on special occasions mentioned above.

When the implementation of QS 2:144 syar'i theorem can be carried out precisely and easily with the help of science (astronomy) and technology, should we retreat to the back of just "facing west"? It should not, except in circumstances we can not determine precisely. Our society is getting smarter. "The direction of the West" in the physical-technical language easily understood around the point of sunset, approximately azimuth 270 degrees. If true fatwa "facing west" was implemented, meaning fatwa lead people to overlook the direction of Africa. With the knowledge of even simple geography, people easily see the direction towards West Indonesia to Africa. Is not that precisely Sura 2:144 denies ordering facing the Grand Mosque in Mecca?

Leads to the point of the Kaaba, or the Grand Mosque is now no longer a problem with the help of astronomy and technology. Is that the point overlooking the Kaaba means we curved rows? Like we make a circle, near the center point of the circle is a curved line. That's what happens on the line rows within the Grand Mosque. The farther from the center of the circle, the circle seemed to grow straight, barely recognizable form of the arch. Thus the rows in places far from Mecca.

We are often brought on mathematical complexity (which is actually not necessary) when it wants high accuracy in determining the direction of Qibla. Mistake one degree in Indonesia (which is about 8000 km to the West Java) can cause large deviations in Mecca (about 140 km in distance). Something similar can we turn it over. In Indonesia there is a very long rows along the 140 km (approximately the distance from Jakarta to Bandung), to overlook the point of him going to the same temple with rows of people stretching back to within 40 meters of the temple, with only about 1 degree angle. So do not imagine when facing the Kaaba, or Grand Mosque point as the line will be curved rows.

38 DETERMINATION OF QIBLA DIRECTION FROM NORT SIDE BY AZIZI TABLE

N COUNTRY AND LALITUDE LONGITUDE DEGREE OF DISTANCE CITY IN DEGREE IN DEGREE QIBLA FROM DIRACTION MAKAH IN FROM KM NORT 1 AFGHANISTAN 33,9391 67,7100 250,24 3067 2 ALBANIA 41,1533 20,1683 133,95 2870 3 ALGERIA 28,0339 1,6596 92,15 3912 4 ANDORRA 42,5462 1,6016 111,37 4253 5 ANGOLA -11,2027 17,8739 33,49 4353 6 ANGUILLA 18,2206 -63,0686 65,59 10550 7 ANTARCTICA -82,8628 -135,000 174,52 13195 8 ANTIGUA AND 17,0608 -61,7964 66,09 10479 BARBUDA 9 ARGENTINA -38,4161 -63,6167 80,49 12619 10 ARMENIA 40,0691 45,0382 194,93 2134 11 ARUBA 12,5211 -69,9683 64,12 11490 12 ASHMERE AND -12,2754 122,9691 292,38 9821 CARTIER ISLAND 13 AUSTRALIA -29,5328 145,4915 282,21 12635 14 AUSTERIA 47,5162 14,5501 133,27 3683 15 AZERBAIJAN 40,1431 47,5769 201,70 2210 16 BAHAMAS 25,0343 -77,3963 58,31 11507 17 BAHRAIN 25,9304 50,6378 247,77 1210 18 BANGLADESH 23,6850 90,3563 277,67 5174 19 BAROBADOS 13,1939 -59,5432 66,98 1042 20 BASSAS DE INDIA -21,4167 39,7000 0,17 4769 21 BELARUS 53,7098 27,9534 159,71 3733 22 BELGIM 50,5039 4,4699 123,28 4466 23 BELIZE 17,1899 -88,4976 54,57 12950 24 BENIN 9,3077 2,3158 66,97 4232 25 BERMODA 32,3214 -64,7574 64,28 10037 26 BHUTAN 27,5142 90,4336 274,06 5138 27 BOLIVIA -16,2902 -63,5887 72,24 12027 28 BOSNIA 34,5199 17,6791 133,66 3231 HERZEGOVINA 29 BOTSWANA -22,3285 24,6849 19,70 5140 30 BOUVET ISLAND -54,4232 3,4132 33,92 9131 31 BRAZIL -14,2350 -51,9253 69,55 10769 32 BRITISH VIRGIN 18,4207 -64,64 65,02 10691 ISLAND 33 BRUNE 4,5353 114,7277 291,00 8271 DARUSSLAM 34 BULGARIA 42,7339 25,4858 146,15 2722 35 BURKINA FASO 12,9140 -1,5616 71,25 4513 36 BURMA 21,9140 95,9562 280,64 5773 37 BURUNDI -3,3731 29,9189 20,94 2964 39

PART II

RENEWABLE ENERGY

40 WHAT IS ENERGY? Matter is made up of invisibly small particles, occupies space, has mass, and exhibits gravitational attraction. Energy, on the other hand, possesses none of these characteristics. Evidence of energy is everywhere. All you need to do is look for motion, heat, and light. The nature of energy is very complex, but it is best described by these characteristics: energy is the ability to do work, work is the application of a force through a distance (e.g., carrying yourself and a loaded back pack up a mountain trail), force is that which can put matter into motion or stop it if it is already moving ( e.g. , you are stopped at a stop sign and the car behind you doesn't see you stop, and can't stop before colliding with your rear bumper, pushing you into the intersection), and motion is a change in distance or direction with time (e.g., making a right hand turn). Energy can be possessed by an object in two different ways, as kinetic energy and potential energy. If this energy is due to the fact that matter is moving or is in use, it is called kinetic energy. If it is due to the position, structure of matter, or composition, it is called potential energy. Potential energy is stored energy. Table I provided a comparison of kinetic and potential energy. Table I. Potential and Kinetic Energies.

Potential Energy Kinetic Energy Water behind a dam (due to its position) Falling water Car parked on a hill (due to its position) Car rolls down a hill Wound clock spring Clock's hands begin to move Gasoline or sugar (due to their chemical composition) Energy appears as movement of the car or muscles and as engine or body heat

ARE THERE DIFFERENT FORMS OF ENERGY? Yes. There are seven forms of energy. Just remember the name: MRS CHEN.* M Mechanical energy (kinetic-energy); its counterpart is stored energy (potential energy) R Radiant energy or sunlight or solar S Sound energy C Chemical energy H Heat energy E Electrical energy

41 N Nuclear energy *Thanks to Rick Hanophy, Smiley Middle School, for the use of this model. "M" represents potential and kinetic energy. They exist in several forms. These are described in Table 2. Table 2. Energy Forms.

POTENTIAL ENERGY Energy Form Energy Due To Example

Chemical Kind and arrangement of small Flashlight battery particles

Nuclear Structure of atom's nucleus Atomic energy KINETIC ENERGY Energy Form Energy Due To Example Heat Random motion of small particles Warmth surrounding a car's engine Sound Ordered periodic motion of small Sound from a Particles headphone

Radiant Bundles of photons Sunlight Mechanical Motion of large pieces of matter Movement of car's wheels CAN ONE FORM OF ENERGY BE CHANGED INTO ANOTHER FORM? Yes, and the most common way to observe this change is as heat. In a flashlight battery, the chemical energy in the battery is converted into electrical energy and, finally into light and some heat energy (put your hands over the light source to feel the heat). The First Law of Thermodynamics states that energy cannot be created or destroyed; it only changes form. Other examples of the change of energy into other forms includes: When natural gas burns in a home or office furnace, chemical energy stored in the gas is converted into heat energy The Sun's radiant energy is converted by plants into chemical energy (a process called photosynthesis).

WHAT ARE THE PRACTICAL SOURCES OF ENERGY? The practical sources of energy include the fossil fuels, natural gas, petroleum (or oil), and coal.

42 Fossil fuels are referred to as nonrenewable energy sources because, once used, they are gone. Scientists are exploring the practicality of other sources called renewable energy sources. These include sun, wind, geothermal, water, and biomass. The renewable energy resources are important in long range energy planning because they will not be depleted.

Natural Gas Sometimes natural gas is confused with gasoline, the fuel in cars. They are not the same. Gasoline is a mixture of liquids, and natural gas is mainly methane and is piped into homes and office buildings where it is used as an energy source for heating, cooking washing, and drying. It is raw material to make other chemicals, and is the cleanest bumming fossil fuel. This means it contributes little environmental pollutants when bummed.

Petroleum or Oil This is the black, thick liquid pumped from below the earth's surface wherever you see an oil rig. To make it useful, it is refined. Refining separates the gasoline portion which is used in transportation. Products from the remaining portions include synthetic rubber, detergents, fertilizers, textiles, paints, and pharmaceuticals.

How Much Oil is Left to Find?

We combined several techniques to conclude that about 1,000 billion barrels of conventional oil remain to be produced. First, we extrapolated published production figures for older oil fields that have begun to decline. The Thistle field off the coast of Britain, for example, will yield about 420 million barrels (a). Second, we plotted the amount of oil discovered so far in some regions against the cumulative number of exploratory wells drilled there. Because larger fields tend to be found first-they are simply too large to miss-the curve rises rapidly and then flattens, eventually reaching a theoretical maximum: for Africa, 192 Gbo. But the time and cost of exploration impose a more practical limit of perhaps 165 Gbo (b). Third, we analyzed the distribution of oil-field sizes in the Gulf of Mexico and other provinces. Ranked according to size and then graphed on a logarithmic scale, the fields tend to fall along a parabola that grows predictably over time (c). (Interestingly, galaxies, urban populations and other natural agglomerations also seem to fall along such parabolas.) Finally, we checked our estimates by matching our projections for oil production in large areas, such as the world outside the Persian Gulf region, to the rise and fall

43 of oil discovery in those places decades earlier (d). -C.J.C. and J.H.L

44

The Authors

COLIN J. CAMPBELL and JEAN H. LAHERRÈRE have each worked in the oil industry for more than 40 years. After completing his Ph.D. in geology at the University of Oxford, Campbell worked for Texaco as an exploration geologist and then at Amoco as chief geologist for Ecuador. His decade-long study of global oil-production trends has led to two books and numerous papers. Laherrère’s early work on seismic refraction surveys contributed to the discovery of Africa’s largest oil field. At Total, a French oil company, he supervised exploration techniques worldwide. Both Campbell and Laherrère are currently associated with Petroconsultants in Geneva.

Further Reading

Updated Hubbert Curves Analyze World Oil Supply. L. F Ivanhoe in World Oil, Vol. 217, No. 11, pages 91-94; November 1996.

45 The Coming Oil Crisis. Colin J. Campbell. Multi-Science Publishing and Petroconsultants, Brentwood, England, 1997.

Oil Back on the Global Agenda. Craig Bond Hatfield in Nature, Vol. 387, page 121; May 8,1997.

Coal Coal is the most abundant fossil fuel. It is not a widely used energy source due to the cost of mining and its impurities, which cause pollution (acid rain). There are two ways to mine coal; underground mining and strip mining. Disadvantage to these methods is the environmental change caused in the process. New ways of using coal are being explored, such as liquefication, in which a product similar to oil is produced.

Solar The sun is 93 million miles away and yet, this ball of hot gases is the primary source of all energy on earth. In the hi ugh temperature of the sun, small atoms of hydrogen are fused, that is, the centers of the two atoms are combined. Fusion releases far greater energy than splitting the atom (fission, see below). Without sunlight, fossil fuels could never have existed. The sun is the supplier of energy which runs the water cycle. The uneven heating of the earth produces wind energy. Wind The unequal heating of the earth's surface by the sun produces wind energy, which can be converted into mechanical and electrical energy. For a long time, the energy of wind has been to drive pumps. Today windmills can be connected to electric generators to turn the wind's motion energy into electrical energy, and wind over 8 miles per hour can be used to generate electricity .It is a renewable, but unpredictable, energy source .

Wood Wood provides U .S. homes and industries as much power as nuclear plants. Burning is the major global source of carbon dioxide in the atmosphere. Worldwide, wood is poor man's oil, providing 50-60% of the people with the barest energy necessities. Roughly half of the earth's forests have disappeared since 1950. Wood is considered a renewable energy source.

Hydroelectric (Falling Water) When water is collected behind dams on large rivers, it provides a source of energy for the production of electricity. The enormous power of falling water is capable of turning giant turbines. These turbines drive the generators, which produce electricity. The degree of power is determined by the amount of water and the distance it falls. Hydroelectric power plants do not cause pollution, but there are fewer and

46 fewer places to build dams. The environmental problem arises because a dam is typically built on a river creating a lake where land once stood. Water is a renewable energy source.

Ocean Tides Ocean tides are very powerful forces. To harness the rising and falling of the tides would be an expensive process, but it would be a very important future source for Eastern United States. Perhaps underwater windmills or floating generating stations could utilize this potential energy source to produce electricity.

Geothermal Geothermal energy refers to the energy deep within the earth. It shows itself in the fountains of boiling water and steam known as geysers. Geothermal energy was generated by the decay of natural radioactive materials within the earth. In addition it is the heat energy remaining within the earth from gravitational formation of the earth. This energy source is not popular in the United States, but Yellowstone has some geysers. Geothermal energy is used to heat some homes, greenhouses, and factories. The actual usable geothermal sites are few, but is considered a renewable energy source.

Biomass This is garbage! As bacteria decomposes organic waste such as manure, septic tank sludge, food scraps, pond- bottom muck, etc., methane is produced. This methane is the same as natural gas from the ground. There are power plants in the United States, which use methane derived from these organic wastes (mainly manure). Some cities produce electricity by burning garbage in especially designed power plants.

Nuclear Fission This is splitting of the uranium atom. In the 1930's scientists found that splitting the nucleus of an uranium atom releases a tremendous amount of heat energy. This knowledge was used to make atom bombs. Today, power companies use the heat produced by nuclear fission to produce electricity. Some people think nuclear energy should be our main source of future energy. Other people feel that the dangers are too great from radioactive waste products, meltdowns, and radiation exposure of workers. Currently the nonrenewable resources supply the majority of our energy needs because we have designed ways to transform their energy on a large scale to meet consumer needs. Regardless of the source of energy, the energy contained in the source is changed into a more useful form –electricity Electricity is sometimes referred to as a secondary energy source. All the other sources are primary.

47 In summary, energy sources can be classified as renewable or nonrenewable: ENERGY Renewable Nonrenewable 1. sun 1. coal 2. water 2. natural gas 3. wood 3. petroleum 4. wind 4. nuclear fission 5. biomass 6. geothermal 7. ocean tides

HOW IS ELECTRICITY MADE? One of the fossil fuels (usually coal) is burned in a power plant to heat water. The hot water turns into steam and forces a machine called a turbine to turn. The turbine powers a generator into electricity which is sent through power lines to provide energy for buildings of all types. In summary, coal -hot water -steam -turbine -generator -electricity. Electricity can also be made from water behind a dam or by windmills. Falling water or rotating windmill blades will cause the turbine to generate electricity. Electricity is the most useful form of energy .We take it for granted because it is such an important part of our life style. It makes our everyday endeavors convenient and practical . For example, electricity makes alarm clocks ring in the morning to wake us for school, keeps our food cool in the refrigerator so that cereal tastes good with milk, operates the blow dryer that styles hair, and runs the furnace that blows warm air throughout our homes in the winter to keep us warm.

WHY IS IT IMPORTANT NOT TO WASTE ELECTRICITY? The conversion of energy from one form to another is covered by a natural law - the Law of Conservation of Energy. This law states that energy can be neither created nor destroyed, it can only be changed from one form to another. This change, however, is one of quantity, not quality .As energy does work, it changes from higher (more concentrated) form of energy to a lower form of energy .For example, of the electrical energy that goes into a typical light bulb, 5% becomes light, the other 95% of the electrical energy is lost as heat. In another example, the chemical energy of gasoline is converted into heat energy in an automobile. A small portion (10%) is converted into mechanical energy that moves the car. The remaining portion (90%) is lost to the environment. You notice this when you stand near an idling car's engine and feel the heat. This concept helps explain why it is important to save (conserve) energy.

HOW CAN WE SAVE ENERGY?

48 Energy saved is energy gained for another day! Saving energy will cut down on pollution and help our fossil fuels last longer, at least, until renewable energy sources become more practical. Conservation is the least expensive source of energy available today. Every bit of electricity that is not used to light a room that no one is in, could be used to operate a computer. Power companies have found that mining this kind of wasted energy is often more profitable than generating more energy. The amount of energy that a utility can get its users to save can be sold to other users; incentive programs for saving energy turn out to be profitable to the utility companies. Because of peak-use problems, the utility must have enough energy available to satisfy the needs of all users at peak hours. This often means building an entire power plant (or more) just to cover the demand over a 2-4 hour portion of the day. When everyone conserves energy, the utility can meet peak demand without a new plant, and the building and maintenance expenses that it would incur. Finding a way to do more with less, benefits everyone. Consumers can actively participate in energy conservation through recycling. Some communities have recycling centers and perhaps your school has a site recycling center. Often recycling centers provide containers for gathered materials, handle all the pick-up, and even supply educational materials to boot! Citizens need to realize that each and every one of us does make a difference. The solution to energy problems will be solved by individuals. While it may seem nebulous we are the ones who need to pass laws or quit polluting, it will be us who will write letters to, and cast votes for, the lawmakers. Likewise it will be individuals who ride the bus or a bike, instead of driving our own cars. The sum of our individual, daily decisions determines the net outcome of the world’s energy use. We want to encourage an honest effort.

What is Renewable Energy? Renewable energy uses energy sources that are continually replenished by nature—the sun, the wind, water, the Earth’s heat, and plants. Renewable energy technologies turn these fuels into usable forms of energy—most often electricity, but also heat, chemicals, or mechanical power.

Why Use Renewable Energy? Today we primarily use fossil fuels to heat and power our homes and fuel our cars. It’s convenient to use coal, oil, and natural gas for meeting our energy needs, but we have a limited supply of these fuels on the Earth. We’re using them much more rapidly than they are being created. Eventually, they will run out. And because of safety concerns and waste disposal problems, the United States will retire much of its nuclear capacity by 2020. In the meantime, the nation’s energy needs are expected to grow by 33 percent during the next 20 years. Renewable energy can help fill the gap.

49 Even if we had an unlimited supply of fossil fuels, using renewable energy is better for the environment. We often call renewable energy technologies “clean” or “green” because they produce few if any pollutants. Burning fossil fuels, however, sends greenhouse gases into the atmosphere, trapping the sun’s heat and contributing to global warming. Climate scientists generally agree that the Earth’s average temperature has risen in the past century. If this trend continues, sea levels will rise, and scientists predict that floods, heat waves, droughts, and other extreme weather conditions could occur more often.

50 Other pollutants are released into the air, soil, and water when fossil fuels are burned. These pollutants take a dramatic toll on the environment—and on humans. Air pollution contributes to diseases like asthma. Acid rain from sulfur dioxide and nitrogen oxides harms plants and fish. Nitrogen oxides also contribute to smog.

ENERGY EFFICIENCY AND RENEWABLE ENERGY

This document was produced for the U.S. Department of Energy (DOE) by the National Renewable Energy Laboratory (NREL), a DOE national laboratory. The document was produced by the Information and Outreach Program at NREL for the DOE Office of Energy Efficiency and Renewable Energy. The Energy Efficiency and Renewable Energy Clearinghouse (EREC) is operated by NCI Information Systems, Inc., for NREL / DOE. The statements contained herein are based on information known to EREC and NREL at the time of printing. No recommendation or endorsement of any product or service is implied if mentioned by EREC. Printed with a renewable-source ink on paper containing at least 50% wastepaper, including 20% postconsumer waste Renewable energy will also March 2001

A PV-system at the Pinnacles National Monument in California eliminates a $20,000 annual fuel bill for a diesel generator that produced each year 143 tons of carbon dioxide—a greenhouse gas. National Park Service, NREL/PIX04924 help us develop energy independence and security. The United States imports more than50 percent of its oil, up from 34 percent in 1973. Replacing some of our petroleum with fuels made from plant matter, for example, could save money and strengthen our energy security. Renewable energy is plentiful, and the technologies are improving all the time. There are many ways to use renewable energy. Most of us already use renewable energy in our daily lives.

51 Will We Increase Energy Efficiency and Build Enough Renewable Energy Systems Before It Becomes Too Late?

Throughout history, groups of people have managed to ignore problems until it was too late to prevent serious consequences. Example: Waiting until the Titanic began sinking before deciding that the ship should have had lifeboats for more than half of the passengers and crew.

Perhaps there is a fatal flaw in our nation's current planning and efforts to keep our energy supplies adequate and affordable. There are several reasons why the fuels often seem to be the least expensive source of energy in the USA:

• Retail costs cover exploration, drilling, extraction, transportation, processing, profit margin and sales taxes but not the cost of creating fuels, because they were created at no cost to mankind. • Retail fuel costs do not reflect true societal costs such as environmental, health, government R & D, subsidies to energy suppliers, and the military costs associated with protecting foreign oil sources. • Fuels are priced as “sustainable” commodities rather than as the “finite” commodities that they are, and thus do not reflect the costs of whatever must replace them as fuel reserves become depleted. • Our federal government continues to use our tax dollars to depress the retail prices of fuels and the electricity from generators powered by fuels.

Government subsidies could continue to make the use of fuels appear to be less expensive than the use of renewable energy sources until nearly all of our world's fuels have been consumed. If we allow that to happen, then we would no longer have the massive amounts of fuels necessary for adequately expanding the use of renewable energy systems and improving energy efficiency.

We may not know the true value of fuels until our remaining fuel reserves run low and we need to find adequate alternatives. Mankind has about 34 cubic miles of oil reserves remaining and is presently consuming about one cubic mile each year. Our inadequate domestic supply of natural gas and our growing dependence on foreign oil imports provide clues that our growing population has no time or fuel to waste if we intend to build enough renewable energy systems to sustain everyone in the USA during the post-fossil-fuel era.

Hydropower Hydropower is our most mature and largest source of renewable power, producing about 10 percent of the nation’s electricity. Existing hydropower capacity is about 77,000 megawatts (MW). Hydropower plants convert the energy in flowing water into electricity. The most common form of hydropower uses a dam on a river to retain a large reservoir of water. Water is released

52 through turbines to generate power. “Run of the river” systems, however, divert water from the river and direct it through a pipeline to a turbine. Hydropower plants produce no air emissions but can affect water quality and wildlife habitats. Therefore, hydropower plants are now being designed and operated to minimize impacts on the river. Some of them are diverting a portion of the flow around their dams to mimic the natural flow of the river. But while this improves the wildlife’s river habitat, it also reduces the power plant’s output. In addition, fish ladders and other approaches, such as improved turbines, are being used to assist fish with migration and lower the number of fish killed.

Bioenergy Bioenergy is the energy derived from biomass (organic matter), such as plants. If you’ve ever burned wood in a fireplace or campfire, you’ve used bioenergy. But we don’t get all of our biomass resources directly from trees or other plants. Many industries, such as those involved in construction or the processing of agricultural products, can create large quantities of unused or residual biomass, which can serve as a bioenergy source.

Biopower After hydropower, biomass is this country’s second-leading resource of renewable energy, accounting for more than 7,000 MW of installed capacity. Some utilities and power generating companies with coal power plants have found that replacing some coal with biomass is a low-cost option to reduce undesirable emissions. As much as 15 percent of the coal may be replaced with biomass. Biomass has less sulfur than coal. Therefore, less sulfur dioxide, which contributes to acid rain, is released into the air. Additionally, using biomass in these boilers reduces nitrous oxide emissions. A process called gasification—the conversion of biomass into gas, which is burned in a gas turbine—is another way to generate electricity. The decay of biomass in landfills also produces gas, mostly methane, which can be burned in a boiler to produce steam for electricity generation or industrial processes. Biomass can also be heated in the absence of oxygen to chemically convert it into a type of fuel oil, called pyrolysis oil. Pyrolysis oil can be used for power generation and as a feedstock for fuels and chemical production.

Biofuels Biomass can be converted directly into liquid fuels, called biofuels. Because biofuels are easy to transport and possess high energy density, they are favored to fuel vehicles and sometimes stationary power generation. The most common biofuel is ethanol, an alcohol made from the fermentation of biomass high in

53 carbohydrates. The current largest source of ethanol is corn. Some cities use ethanol as a gasoline additive to help meet air quality standards for

2 Hydropower is our most mature and largest source of renewable power…

A small-scale hydropower system in King Cove, Alaska, provides residents in this remote area with a less expensive source of electricity. Duane Hippe, NREL/PIX04410 3 If you’ve ever burned wood in a fireplace or campfire, you've used bioenergy. ozone. Flex-fuel vehicles are also now on the market, which can use a mixture of gasoline and ethanol, such as E85—a mixture of 85 percent ethanol and 15 percent gasoline. Another biofuel is biodiesel, which can be made from vegetable and animal fats. Biodiesel can be used to fuel a vehicle or as a fuel additive to reduce emissions. Corn ethanol and biodiesel provide about 0.4 percent of the total liquid fuels market. To increase our available supply of biofuels, researchers are testing crop residues— such as cornstalks and leaves—wood chips, food waste, grass, and even trash as potential biofuel sources.

Biobased Products Biomass—corn, wheat, soybeans, wood, and residues—can also be used to produce chemicals and materials that we normally obtain from petroleum. Industry has already begun to use cornstarch to produce commodity plastics, such as shrinkwrap, plastic eating utensils, and even car bumpers. Commercial development is underway to make thermoset plastics, like electrical switch plate covers, from wood residues.

Geothermal Energy The Earth’s core, 4,000 miles below the surface, can reach temperatures of 9000° F.

54

This heat—geothermal energy—flows outward from the core, heating the surrounding area, which can form underground reservoirs of hot water and steam. These reservoirs can be tapped for a variety of uses, such as to generate electricity or heat buildings. By using geothermal heat pumps (GHPs), we can even take advantage of the shallow ground’s stable temperature for heating and cooling buildings. The geothermal energy potential in the uppermost 6 miles of the Earth’s crust amounts to 50,000 times the energy of all oil and gas resources in the world. In the United States, most geothermal reservoirs are located in the western states, Alaska, and Hawaii. GHPs, however, can be used almost anywhere.

Geothermal Electricity Production Geothermal power plants access the underground steam or hot water from wells drilled a mile or more into the earth. The steam or hot water is piped up from the well to drive a conventional steam turbine, which powers an electric generator. Typically, the water is then returned to the ground to recharge the reservoir and complete the renewable energy cycle. There are three types of geothermal power plants: dry steam, flash steam, and binary cycle. Dry steam plants draw from reservoirs of steam, while both flash steam and binary cycle plants draw from reservoirs of hot water. Flash steam plants typically use water at temperatures greater than 360°F. Unlike both steam and flash plants, binary-cycle plants transfer heat from the water to what’s called a working fluid. Therefore binary cycle plants can operate using water at lower temperatures of about 225° to 360°F. All of the U.S. geothermal power plants are in California, Nevada, Utah, and Hawaii. Altogether about 2800 MW of geothermal electric capacity is produced annually in this country.

Geothermal Direct Use If you’ve ever soaked in a natural hot spring, you’re one of millions of people around the world who has enjoyed the direct use of

55

This gasifier in Burlinton, Vermont, converts biomass into a clean gas for electricity production Warren Gretz, NREL/PIX04744

The Steamboat Hills geothermal power plant in Steamboat Springs, Nevada has an electricity generation capacity of 13.5 MW. Joel Renner, INEEL, NREL/PIX07658 geothermal energy. Direct-use applications require geothermal temperatures between about 70° to 302°F—lower than those required for electricity generation. The United States already has about 1,300 geothermal direct-use systems in operation. In a direct-use system, a well is drilled into a geothermal reservoir, which provides a steady stream of hot water. Some systems use the water directly, but most pump the water through what’s called a heat exchanger. The heat exchanger keeps the water separate from a working fluid (water or a mixture of water and usually antifreeze), which is heated by the geothermal water. The working fluid then flows through piping, distributing the heat directly for its intended use. The heated water or fluid can be used in a building to replace the traditional heat source—often natural gas—of a boiler, furnace, and hot water heater. Some cities and towns actually have large direct-use heating systems— called district heating— that provide many buildings with heat. Geothermal direct use is also used in agriculture— such as for fish farms and to heat greenhouses—and for industrial food processing (vegetable dehydration).

Geothermal Heat Pumps While air temperatures can vary widely through the seasons, the temperatures of

56 the shallow ground only range from 50° to 70°F depending on latitude. GHPs draw on this relatively stable temperature as a source for heating buildings in the winter and keeping them cool in the summer. Through underground piping, a GHP discharges heat from inside a building into the ground in the summer, much like a refrigerator uses electricity to keep its interior cool while releasing heat into your kitchen. In the winter, this process is reversed; the GHP extracts heat from the ground and releases it into a building. Because GHPs actually move heat between homes and the earth, instead of burning fuels, they operate very cleanly and efficiently. In fact, GHPs are at least three times more efficient than even the most energyefficient furnaces on the market today.

Solar Energy Solar technologies tap directly into the infinite power of the sun and use that energy to produce heat, light, and power. Solar energy can be used to cook food, heat water and generate electricity. It remains the cleanest energy source an it is renewable. It is the hope for the energy source of the future and scientists at NREL are actively working on ways for solar energy to supply more our energy needs!

Alternative Energy Solutions - Solar LED Street Lighting

The sun is the biggest source of renewable energy on the planet. Solar power doesn't use fossil fuels, and is a non-renewable energy source. As the price of fossil fuels and other non-renewable energy sources skyrocket, consumers are being forced to think about other sources of energy. This is why, over the years, Solar Energy has found its way into our homes, offices, gardens and streets; while protecting the planet and helping us to save a fortune on our electricity bills.

Furthermore, the recent innovations in Solid State Lighting technology have made it possible for the mass adoption of high-efficacy energy efficient LED luminaires in conventional lighting applications. When equipped with solar power, LED street lighting offers a unique solution to reduction in electricity bills for city councils and Solar LED street lighting applications comprise of 3 phases: energy collection (solar panels), energy storage and energy conversion. Solar Panels form the core element of the design which collects and converts solar energy into electric energy which is then stored into the Energy Storage devices (e.g. high energy density batteries) during the day. During the night, power is fed into the LED arrays from the batteries through a DC/DC converter circuitry (or DC/AC if power is to be fed back into the energy grid). The entire operation from charging to monitoring the entire system is controlled by an

57 MCU that supports a higher number of I/O pins to receive external control signals.

Passive Solar Lighting and Heating People have used the sun to heat and light their homes for centuries. Ancient Native Americans built their dwellings directly into south-facing cliff walls because they knew the sun travels low across the southern sky in the Northern Hemisphere during the winter. They also knew the massive rock of the cliff would absorb heat in winter and protect against wind and snow. At the same time, the cliffdwelling design blocked sunlight during the summer, when the sun is higher in the sky, keeping their dwellings cool. The modern version of this sun-welcoming design is called passive solar because no pumps, fans, or other mechanical devices are used. Its most basic features include large, south-facing windows that fill the home with natural sunlight, and dark tile or brick floors that store the sun’s heat and release it back into the home at night. In the summer, when the sun is higher in the sky, window overhangs block direct sunlight, which keeps the house cool. Tile and brick floors also remain cool during the summer. Passive solar design combined with energy efficiency will go even further. Energy-efficient features such as energysaving windows and appliances, along with good insulation and weatherstripping, can make a huge difference in energy and cost savings.

Solar Water Heating

58 Solar energy can be used to heat water for your home or your swimming pool. Most solar water-heating systems consist of a solar collector and a water storage tank. Solar water-heating systems use collectors, generally mounted on a south- facing roof, to heat either water or a heat-transfer fluid, such as a nontoxic antifreeze. The heated water is then stored in a water tank similar to one used in a conventional gas or electric water-heating system. 4 Altogether about2800 MW of geothermal electric capacity is produced annually in this country.

This homeowner in Aurora, Colorado, uses a GHP to heat and cool his home. Warren Gretz, NREL/PIX06537 There are basically three types of solar collectors for heating water: flatplate, evacuatedtube, and concentrating. The most common type, a flat-plate collector, is an insulated, weatherproof box containing a dark absorber plate under a transparent cover. Evacuated- tube collectors are made up of rows of parallel, transparent glass tubes. Each tube consists of a glass outer tube and an inner tube, or absorber, covered with a coating that absorbs solar energy but inhibits heat loss. Concentrating collectors for residential applications are usually parabolic-shaped mirrors (like a trough) that concentrate the sun’s energy on an absorber tube called a receiver that runs along the axis of the mirrored trough and contains a heat-transfer fluid. All three types of collectors heat water by circulating household water or a heat- transfer fluid such as a nontoxic antifreeze from the collector to the water storage tanks. Collectors do this either passively or actively. Passive solar water-heating systems use natural convection or household water pressure to circulate water through a solar collector to a storage tank. They have no electric components that could break, a feature that generally makes them more reliable, easier to maintain, and possibly longer lasting than active systems. An active system uses an electric pump to circulate water or nontoxic antifreeze

59 through the system. Active systems are usually more expensive than passive systems, but they are also more efficient. Active systems also can be easier to retrofit than passive systems because their storage tanks do not need to be installed above or close to the collectors. Also, the moving water in the system will not freeze in cold climates. But because these systems use electricity, they will not function in a power outage. That’s why many active systems are now combined with a small solar-electric panel to power the pump. The amount of hot water a solar water heater produces depends on the type and size of the system, the amount of sun available at the site, proper installation, and the tilt angle and orientation of the collectors. But if you’re currently using an electric water heater, solar water heating is a cost-effective alternative. If you own a swimming pool, heating the water with solar collectors can also save you money.

Solar Electricity Solar electricity or photovoltaic (PV) technology converts sunlight directly into electricity. Solar electricity has been a prime source of power for space vehicles since the inception of the space program. It has also been used to power small electronics and rural and agricultural applications for three decades. During the last decade, a strong solar electric market has emerged for powering urban grid-connected homes and buildings as a result of advances in solar technology along with global changes in electric industry restructuring. Although many types of solar electric systems are available today, they all consist of basically three main items: modules that convert sunlight into electricity; inverters that convert that electricity into alternating current so it can be used by most household appliances; and possibly or sometimes batteries that store excess electricity produced by the system. The remainder of the system comprises equipment such as wiring, circuit breakers, and support structures. Today’s modules can be built into glass skylights and walls. Some modules resemble traditional roof shingles, but they generate electricity, and some come with built-in inverters. The solar modules available today are more efficient and versatile than ever before. In over 30 states, any additional power produced by a PV system, which is not being used by a home or building, can be fed back to the electric grid through a process known as net metering. Net metering allows electricity customers to pay only for their “net” electricity, or the 5 Passive solar building techniques turn homes into huge solar collectors.

60

The Four Times Square Building in New York City uses thin-film PV panels to reduce the building’s power load from the utility grid. Andrew Gordon and Fox & Fowle Architects, NREL/PIX09052 amount of power consumed from their utility minus the power generated by their PV system. This metering arrangement allows consumers to realize full retail value for 100 percent of the PV energy produced by their systems. Grid-connected PV systems do not require batteries. However, some grid connected systems use them for emergency backup power. And of course in remote areas, solar electricity is often a economic alternative to expensive distribution line extensions incurred by a customer first connecting to the utility grid. Electricity produced by solar electric systems in remote locations is stored in batteries. Batteries will usually store electricity produced by a solarelectric system for up to three days. What type of system to purchase will depend on the energy-efficiency of your home, your home’s location, and your budget. Before you size your system, try reducing energy demand through energyefficient measures. Purchasing energy- saving appliances and lights, for example, will reduce your electrical demand and allow you to purchase a smaller solar-electric system to meet your energy needs or get more value from a larger system. Energy efficiency allows you to start small and then add on as your energy needs increase.

Solar Thermal Electricity Unlike solar-electric systems that convert sunlight into electricity, solar thermal electric systems convert the sun’s heat into electricity. This technology is used primarily in large-scale power plants for powering cities and communities, especially in the Southwest where consistent hours of sunlight are greater than other parts of the United States. Concentrating solar power (CSP) technologies convert solar energy into electricity by using mirrors to focus sunlight onto a component called a receiver. The receiver transfers the heat to a conventional engine-generator—such as a steam turbine—that generates electricity. There are three types of CSP systems:

61 power towers (central receivers), parabolic troughs, and dish/engine systems. A power tower system uses a large field of mirrors to concentrate sunlight onto the top of a tower, where a receiver sits. Molten salt flowing through the receiver is heated by the concentrated sunlight. The salt’s heat is turned into electricity by a conventional steam generator. Parabolictrough systems concentrate the sun’s energy through long, parabolic- shaped mirrors. Sunlight is focused on a pipe filled with oil that runs down the axis of the trough. When the oil gets hot, it is used to boil water in a conventional steam generator to produce electricity. A dish/engine system uses a mirrored dish(similar in size to a large satellite dish). The dish-shaped surface focuses and concentrates the focal point of the dish (above and center the sun’s heat onto a receiver at of the collectors). The receiver absorbs the sun’s heat and transfers it to a fluid within an engine, where the heat causes the fluid to expand against a piston to produce mechanical power. The mechanical power is then used to run a generator or alternator to produce electricity. Concentrating solar technologies can be used to generate electricity for a variety of applications, ranging from remote power systems as small as a few kilowatts (kW) up to grid-connected applications of 200 MW or more. A354-MW power plant in Southern California, which consists of nine trough power plants, meets the energy needs of more than 350,000 people and is the world’s largest solar energy power plant.

Wind Energy For hundreds of years, people have used windmills to harness the wind’s energy. Today’s wind turbines, which operate differently from windmills, are a much more efficient technology. Wind turbine technology may look simple: the wind spins turbine blades around a central hub; the hub is connected to a shaft, which powers a generator to make electricity. However, turbines are highly sophisticated power systems that capture the wind’s energy by means of new blade designs or airfoils. Modern, mechanical drive systems, combined with advanced generators, convert that energy into electricity. Wind turbines that provide electricity to the utility grid range in size from 50 kW to about 2500 MW

62 Wind power: worldwide installed capacity [1]

Wind power: worldwide installed capacity forecast [1][2]

Burbo Bank Offshore Wind Farm, at the entrance to the River Mersey in North West England

Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships.

The total amount of economically extractable power available from the wind is considerably more than present human power use from all sources.[3] At the end of 2010, worldwide nameplate capacity of wind-powered generators was 197 gigawatts (GW).[4] Wind power now has the capacity to generate 430 TWh annually, which is about 2.5% of worldwide electricity usage.[4][5] Over the past five years the average annual growth in new installations has been 27.6 percent. Wind power market penetration is expected to reach 3.35 percent by 2013 and 8 percent by 2018.[6][7] Several countries have already achieved relatively high levels of wind power penetration, such as 21% of stationary electricity production in Denmark,[4] 18% in Portugal,[4] 16% in Spain,[4] 14% in Ireland[8] and 9% in Germany in 2010.[4][9] As of 2011, 83 countries around the world are using wind power on a commercial basis.[9]

A large wind farm may consist of several hundred individual wind turbines which are connected to the electric power transmission network. Offshore wind

63 power can harness the better wind speeds that are available offshore compared to on land, so offshore wind power’s contribution in terms of electricity supplied is higher.[10] Small onshore wind facilities are used to provide electricity to isolated locations and utility companies increasingly buy back surplus electricity produced by small domestic wind turbines. Although a variable source of power, the intermittency of wind seldom creates problems when using wind power to supply up to 20% of total electricity demand, but as the proportion rises, increased costs, a need to use storage such as pumped-storage hydroelectricity, upgrade the grid, or a lowered ability to supplant conventional production may occur.[11][12][13] Power management techniques such as excess capacity, storage, dispatchable backing supply (usually natural gas), exporting and importing power to neighboring areas or reducing demand when wind production is low, can mitigate these problems.

Wind power, as an alternative to fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, and uses little land. In operation, the overall cost per unit of energy produced is similar to the cost for new coal and natural gas installations.[14] The construction of wind farms is not universally welcomed, but any effects on the environment from wind power are generally much less problematic than those of any other power source.[15]

History Main article: History of wind power

Medieval depiction of a wind mill

Windmills are typically installed in favourable windy locations. In the image, wind power generators in Spain near an Osborne bull

64 Humans have been using wind power for at least 5,500 years to propel sailboats and sailing ships. Windmills have been used for irrigation pumping and for milling grain since the 7th century AD in what is now Afghanistan, India, Iran and Pakistan.[citation needed]

In the US, the development of the "water-pumping windmill" was the major factor in allowing the farming and ranching of vast areas otherwise devoid of readily accessible water. Windpumps contributed to the expansion of rail transport systems throughout the world, by pumping water from water wells for the steam locomotives.[16] The multi-bladed wind turbine atop a lattice tower made of wood or steel was, for many years, a fixture of the landscape throughout rural America. When fitted with generators and battery banks, small wind machines provided electricity to isolated farms.

In July 1887, a Scottish academic, Professor James Blyth, undertook wind power experiments that culminated in a UK patent in 1891.[17] In the US, Charles F. Brush produced electricity using a wind powered machine, starting in the winter of 1887-1888, which powered his home and laboratory until about 1900. In the 1890s, the Danish scientist and inventor Poul la Cour constructed wind turbines to generate electricity, which was then used to produce hydrogen.[17] These were the first of what was to become the modern form of wind turbine.

Small wind turbines for lighting of isolated rural buildings were widespread in the first part of the 20th century. Larger units intended for connection to a distribution network were tried at several locations including Balaklava USSR in 1931[citation needed] and in a 1.25 megawatt (MW) experimental unit in Vermont in 1941.[citation needed]

In the 1970s, U.S. industries teamed with NASA in a research program which created the NASA wind turbines, developing and testing many of the features of modern utility-scale turbines.[citation needed]

The modern wind power industry began in 1979 with the serial production of wind turbines by Danish manufacturers Kuriant, Vestas, Nordtank, and Bonus.[citation needed] These early turbines were small by today's standards, with capacities of 20–30 kW each. Since then, they have increased greatly in size, with the Enercon E-126 capable of delivering up to 7 MW, while wind turbine production has expanded to many countries.

Today, wind generated energy is the fastest growing source of renewable energy[citation needed]. Wind power is expected to grow worldwide in the twenty- first century.[18]

65 Wind energy Main article: Wind energy

Map of available wind power for the United States. Color codes indicate wind power density class.

The Earth is unevenly heated by the sun, such that the poles receive less energy from the sun than the equator; along with this, dry land heats up (and cools down) more quickly than the seas do. The differential heating drives a global atmospheric convection system reaching from the Earth's surface to the stratosphere which acts as a virtual ceiling. Most of the energy stored in these wind movements can be found at high altitudes where continuous wind speeds of over 160 km/h (99 mph) occur. Eventually, the wind energy is converted through friction into diffuse heat throughout the Earth's surface and the atmosphere.

The total amount of economically extractable power available from the wind is considerably more than present human power use from all sources.[3] The most comprehensive study as of 2005[19] found the potential of wind power on land and near-shore to be 72 TW, equivalent to 54,000 MToE (million tons of oil equivalent) per year, or over five times the world's current energy use in all forms. The potential takes into account only locations with mean annual wind speeds ≥ 6.9 m/s at 80 m. The study assumes six 1.5 megawatt, 77 m diameter turbines per square kilometer on roughly 13% of the total global land area (though that land would also be available for other compatible uses such as farming). The authors acknowledge that many practical barriers would need to be overcome to reach this theoretical capacity.

Others authors disagree with the bottom-up methodology and cites problems with such methods which can be "violating the first principle of energy conservation". [20][21] The principle is that the amount of energy which can be extracted from wind power can actually exceed the power currently present in the lower atmosphere using such bottom-up analyses. (i.e. There is 100 TW of total power in the lower 200m of the entire atmosphere and somes studies go

66 well over that limit. [20][21]) Their results show 1 TWe for the limit of wind power energy, which is much lower than previous estimates.

The practical limit to exploitation of wind power will be set by economic and environmental factors, since the resource available is far larger than any practical means to develop it.

Distribution of wind speed

Distribution of wind speed (red) and energy (blue) for all of 2002 at the Lee Ranch facility in Colorado. The histogram shows measured data, while the curve is the Rayleigh model distribution for the same average wind speed.

The strength of wind varies, and an average value for a given location does not alone indicate the amount of energy a wind turbine could produce there. To assess the frequency of wind speeds at a particular location, a probability distribution function is often fit to the observed data. Different locations will have different wind speed distributions. The Weibull model closely mirrors the actual distribution of hourly wind speeds at many locations. The Weibull factor is often close to 2 and therefore a Rayleigh distribution can be used as a less accurate, but simpler model.

Wind farms

Landowners in the US typically receive $3,000 to $5,000 per year in rental income from each wind turbine, while farmers continue to grow crops or graze cattle up to the foot of the turbines.[22] Main article: Wind farm

67 A wind farm is a group of wind turbines in the same location used for production of electric power. A large wind farm may consist of several hundred individual wind turbines, and cover an extended area of hundreds of square miles, but the land between the turbines may be used for agricultural or other purposes. A wind farm may also be located offshore.

Many of the largest operational onshore wind farms are located in the US. As of November 2010, the Roscoe Wind Farm is the largest onshore wind farm in the world at 781.5 MW, followed by the Horse Hollow Wind Energy Center (735.5 MW). As of November 2010, the Thanet Wind Farm in the UK is the largest offshore wind farm in the world at 300 MW, followed by Horns Rev II (209 MW) in Denmark.

There are many large wind farms under construction and these include BARD Offshore 1 (400 MW), Clyde Wind Farm (548 MW), Greater Gabbard wind farm (500 MW), Lincs Wind Farm (270 MW), London Array (1000 MW), Lower Snake River Wind Project (343 MW), Macarthur Wind Farm (420 MW), Shepherds Flat Wind Farm (845 MW), Sheringham Shoal (317 MW), and the Walney Wind Farm (367 MW).

Wind power usage Main article: Wind power by country

Worldwide there are now many thousands of wind turbines operating, with a total nameplate capacity of 194,400 MW.[23] World wind generation capacity more than quadrupled between 2000 and 2006, doubling about every three years. The United States pioneered wind farms and led the world in installed capacity in the 1980s and into the 1990s. In 1997 German installed capacity surpassed the U.S., a position it held until passed by the U.S. in 2008. China rapidly expanded its wind installations in the late 2000s and passed the U.S. in 2010 to become the world leader.

Europe accounted for 48% of the world total in 2009. In 2010, Spain became Europe's leading producer of wind energy, achieving 42,976 GWh. However, Germany holds the first place in Europe in terms of installed capacity, with a total of 27,215 MW at December 31, 2010.[24] Wind power accounts for approximately 21% of electricity use in Denmark,[4] 18% in Portugal,[4] 16% in Spain,[4][24] 14% in the Republic of Ireland,[4] and 9% in Germany.[4][25]

Top 10 countries by nameplate windpower capacity (2010)[4] Country Windpower capacity (MW) China 44,733 United States 40,180

68 Top 10 countries by nameplate windpower capacity (2010)[4] Country Windpower capacity (MW) Germany 27,215 Spain 20,676 India 13,066 Italy 5,797 France 5,660 United Kingdom 5,204 Canada 4,008 Denmark 3,734 Top 10 EU countries by windpower electricity production (December 2010)[24] Country Windpower electricity production (GWh) Spain 42,976 Germany 35,500 United Kingdom 11,440 France 9,600 Portugal 8,852 Denmark 7,808 Netherlands 3,972 Sweden 3,500 Ireland 3,473 Greece 2,200 Austria 2,100

Growth trends

Worldwide installed capacity 1997–2020 [MW], developments and prognosis. Data source: WWEA

In 2010, more than half of all new wind power was added outside of the traditional markets in Europe and North America. This was largely from new construction in China, which accounted for nearly half the new wind installations (16.5 GW). [26]

69 Global Wind Energy Council (GWEC) figures show that 2007 recorded an increase of installed capacity of 20 GW, taking the total installed wind energy capacity to 94 GW, up from 74 GW in 2006. Despite constraints facing supply chains for wind turbines, the annual market for wind continued to increase at an estimated rate of 37%, following 32% growth in 2006. In terms of economic value, the wind energy sector has become one of the important players in the energy markets, with the total value of new generating equipment installed in 2007 reaching €25 billion, or US$36 billion.[27]

Although the wind power industry was affected by the global financial crisis in 2009 and 2010, a BTM Consult five year forecast up to 2013 projects substantial growth. Over the past five years the average growth in new installations has been 27.6 percent each year. In the forecast to 2013 the expected average annual growth rate is 15.7 percent.[6][7] More than 200 GW of new wind power capacity could come on line before the end of 2013. Wind power market penetration is expected to reach 3.35 percent by 2013 and 8 percent by 2018.[6][7]

Offshore wind power Main article: Offshore wind power

Aerial view of Lillgrund Wind Farm, Sweden

Offshore wind power refers to the construction of wind farms in bodies of water to generate electricity from wind. Better wind speeds are available offshore compared to on land, so offshore wind power’s contribution in terms of electricity supplied is higher.[10]

Siemens and Vestas are the leading turbine suppliers for offshore wind power. DONG Energy, Vattenfall and E.ON are the leading offshore operators.[10] As of October 2010, 3.16 GW of offshore wind power capacity was operational, mainly in Northern Europe. According to BTM Consult, more than 16 GW of additional capacity will be installed before the end of 2014 and the UK and Germany will become the two leading markets. Offshore wind power capacity is expected to reach a total of 75 GW worldwide by 2020, with significant contributions from China and the US.[10]

70 Electricity generation

Typical components of a wind turbine (gearbox, rotor shaft and brake assembly) being lifted into position

In a wind farm, individual turbines are interconnected with a medium voltage (often 34.5 kV), power collection system and communications network. At a substation, this medium-voltage electric current is increased in voltage with a transformer for connection to the high voltage electric power transmission system.

The surplus power produced by domestic microgenerators can, in some jurisdictions, be fed into the network and sold to the utility company, producing a retail credit for the microgenerators' owners to offset their energy costs.[28][29]

Grid management

Induction generators, often used for wind power, require reactive power for excitation so substations used in wind-power collection systems include substantial capacitor banks for power factor correction. Different types of wind turbine generators behave differently during transmission grid disturbances, so extensive modelling of the dynamic electromechanical characteristics of a new wind farm is required by transmission system operators to ensure predictable stable behaviour during system faults (see: Low voltage ride through). In particular, induction generators cannot support the system voltage during faults, unlike steam or hydro turbine-driven synchronous generators. Doubly fed machines generally have more desirable properties for grid interconnection[citation needed]. Transmission systems operators will supply a wind farm developer with a grid code to specify the requirements for interconnection to the transmission grid. This will include power factor, constancy of frequency and dynamic behavior of the wind farm turbines during a system fault.[30][31]

Capacity factor

Since wind speed is not constant, a wind farm's annual energy production is never as much as the sum of the generator nameplate ratings multiplied by the

71 total hours in a year. The ratio of actual productivity in a year to this theoretical maximum is called the capacity factor. Typical capacity factors are 20–40%, with values at the upper end of the range in particularly favourable sites.[32] For example, a 1 MW turbine with a capacity factor of 35% will not produce 8,760 MW·h in a year (1 × 24 × 365), but only 1 × 0.35 × 24 × 365 = 3,066 MW·h, averaging to 0.35 MW. Online data is available for some locations and the capacity factor can be calculated from the yearly output.[33][34]

Unlike fueled generating plants, the capacity factor is affected by several parameters, including the variability of the wind at the site, but also the generator size- having a smaller generator would be cheaper and achieve higher capacity factor, but would make less electricity (and money) in high winds.[35] Conversely a bigger generator would cost more and generate little extra power and, depending on the type, may stall out at low wind speed. Thus an optimum capacity factor can be used, which is usually around 20-35%.

In a 2008 study released by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy, the capacity factor achieved by the wind turbine fleet is shown to be increasing as the technology improves. The capacity factor achieved by new wind turbines in 2004 and 2005 reached 36%.[36]

Penetration

Wind energy "penetration" refers to the fraction of energy produced by wind compared with the total available generation capacity. There is no generally accepted "maximum" level of wind penetration. The limit for a particular grid will depend on the existing generating plants, pricing mechanisms, capacity for storage or demand management, and other factors. An interconnected electricity grid will already include reserve generating and transmission capacity to allow for equipment failures; this reserve capacity can also serve to regulate for the varying power generation by wind plants. Studies have indicated that 20% of the total electrical energy consumption may be incorporated with minimal difficulty.[37] These studies have been for locations with geographically dispersed wind farms, some degree of dispatchable energy, or hydropower with storage capacity, demand management, and interconnection to a large grid area export of electricity when needed. Beyond this level, there are few technical limits, but the economic implications become more significant. Electrical utilities continue to study the effects of large (20% or more) scale penetration of wind generation on system stability and economics.[38][39][40][41]

At present, a few grid systems have penetration of wind energy above 5%: Denmark (values over 19%), Spain and Portugal (values over 11%), Germany and the Republic of Ireland (values over 6%). But even with a modest level of penetration, there can be times where wind power provides a substantial

72 percentage of the power on a grid. For example, in the morning hours of 8 November 2009, wind energy produced covered more than half the electricity demand in Spain, setting a new record.[42]

Variability and intermittency Main articles: Intermittent energy source and wind power forecasting

Wildorado Wind Farm in Oldham County in the Texas Panhandle, as photographed from U.S. Route 385

Electricity generated from wind power can be highly variable at several different timescales: from hour to hour, daily, and seasonally. Annual variation also exists, but is not as significant. Related to variability is the short-term (hourly or daily) predictability of wind plant output. Like other electricity sources, wind energy must be "scheduled". Wind power forecasting methods are used, but predictability of wind plant output remains low for short-term operation.

Because instantaneous electrical generation and consumption must remain in balance to maintain grid stability, this variability can present substantial challenges to incorporating large amounts of wind power into a grid system. Intermittency and the non-dispatchable nature of wind energy production can raise costs for regulation, incremental operating reserve, and (at high penetration levels) could require an increase in the already existing energy demand management, load shedding, or storage solutions or system interconnection with HVDC cables. At low levels of wind penetration, fluctuations in load and allowance for failure of large generating units requires reserve capacity that can also regulate for variability of wind generation. Wind power can be replaced by other power stations during low wind periods. Transmission networks must already cope with outages of generation plant and daily changes in electrical demand. Systems with large wind capacity components may need more spinning reserve (plants operating at less than full load).[43][44]

Pumped-storage hydroelectricity or other forms of grid energy storage can store energy developed by high-wind periods and release it when needed.[45] Stored energy increases the economic value of wind energy since it can be shifted to displace higher cost generation during peak demand periods. The potential

73 revenue from this arbitrage can offset the cost and losses of storage; the cost of storage may add 25% to the cost of any wind energy stored, but it is not envisaged that this would apply to a large proportion of wind energy generated. For example, in the UK, the 2 GW Dinorwig pumped storage plant evens out electrical demand peaks, and allows base-load suppliers to run their plant more efficiently. Although pumped storage power systems are only about 75% efficient, and have high installation costs, their low running costs and ability to reduce the required electrical base-load can save both fuel and total electrical generation costs.[46][47]

In particular geographic regions, peak wind speeds may not coincide with peak demand for electrical power. In the US states of California and Texas, for example, hot days in summer may have low wind speed and high electrical demand due to air conditioning. Some utilities subsidize the purchase of geothermal heat pumps by their customers, to reduce electricity demand during the summer months by making air conditioning up to 70% more efficient;[48] widespread adoption of this technology would better match electricity demand to wind availability in areas with hot summers and low summer winds. Another option is to interconnect widely dispersed geographic areas with an HVDC "Super grid". In the US it is estimated that to upgrade the transmission system to take in planned or potential renewables would cost at least $60 billion.[49]

In the UK, demand for electricity is higher in winter than in summer, and so are wind speeds.[50][51] Solar power tends to be complementary to wind.[52][53] On daily to weekly timescales, high pressure areas tend to bring clear skies and low surface winds, whereas low pressure areas tend to be windier and cloudier. On seasonal timescales, solar energy typically peaks in summer, whereas in many areas wind energy is lower in summer and higher in winter.[54] Thus the intermittencies of wind and solar power tend to cancel each other somewhat. The Institute for Solar Energy Supply Technology of the University of Kassel pilot-tested a combined power plant linking solar, wind, biogas and hydrostorage to provide load-following power around the clock, entirely from renewable sources.[55]

A report on Denmark's wind power noted that their wind power network provided less than 1% of average demand 54 days during the year 2002.[56] Wind power advocates argue that these periods of low wind can be dealt with by simply restarting existing power stations that have been held in readiness or interlinking with HVDC.[57] Electrical grids with slow-responding thermal power plants and without ties to networks with hydroelectric generation may have to limit the use of wind power.[56]

Conversely, on particularly windy days, even with penetration levels of 16%, wind power generation can surpass all other electricity sources in a country.[58]

74 In Spain, on November 8, 2009 wind power production reached the highest percentage of electricity production till then, with wind farms covering 53% of the total demand.[59][60]

Three reports on the wind variability in the UK issued in 2009, generally agree that variability of wind needs to be taken into account, but it does not make the grid unmanageable; and the additional costs, which are modest, can be quantified.[61] A 2006 International Energy Agency forum presented costs for managing intermittency as a function of wind-energy's share of total capacity for several countries, as shown:

Increase in system operation costs, Euros per MW·h, for 10% and 20% wind share[12]

10% 20% Germany 2.5 3.2 Denmark 0.4 0.8 Finland 0.3 1.5 Norway 0.1 0.3 Sweden 0.3 0.7

Capacity credit and fuel saving

Many commentators concentrate on whether or not wind has any "capacity credit" without defining what they mean by this and its relevance. Wind does have a capacity credit, using a widely accepted and meaningful definition, equal to about 20% of its rated output (but this figure varies depending on actual circumstances). This means that reserve capacity on a system equal in MW to 20% of added wind could be retired when such wind is added without affecting system security or robustness. But the precise value is irrelevant since the main value of wind (in the UK, worth 5 times the capacity credit value[62]) is its fuel and CO2 savings.

According to a 2007 Stanford University study published in the Journal of Applied Meteorology and Climatology, interconnecting ten or more wind farms can allow an average of 33% of the total energy produced to be used as reliable, baseload electric power, as long as minimum criteria are met for wind speed and turbine height.[63][64]

75 Economics

Cost trends

Brazos Wind Farm in Texas

Turbine blade convoy passing through Edenfield in the UK.

Wind power has low ongoing costs, but a moderate capital cost. The estimated average cost per unit incorporates the cost of construction of the turbine and transmission facilities, borrowed funds, return to investors (including cost of risk), estimated annual production, and other components, averaged over the projected useful life of the equipment, which may be in excess of twenty years. Energy cost estimates are highly dependent on these assumptions so published cost figures can differ substantially. A 2011 report from the American Wind Energy Association stated, "Wind's costs have dropped over the past two years, in the range of 5 to 6 cents per kilowatt-hour recently.... about 2 cents cheaper than coal-fired electricity, and more projects were financed through debt arrangements than tax equity structures last year.... winning more mainstream acceptance from Wall Street's banks.... Equipment makers can also deliver products in the same year that they are ordered instead of waiting up to three years as was the case in previous cycles.... 5,600 MW of new installed capacity is under construction in the United States, more than double the number at this point in 2010. Thirty-five percent of all new power generation built in the United States since 2005 has come from wind, more than new gas and coal plants combined, as power providers are increasingly enticed to wind as a convenient hedge against unpredictable commodity price moves."[65]

76 A British Wind Energy Association report gives an average generation cost of onshore wind power of around 3.2 pence (between US 5 and 6 cents) per kW·h (2005).[66] Cost per unit of energy produced was estimated in 2006 to be comparable to the cost of new generating capacity in the US for coal and natural gas: wind cost was estimated at $55.80 per MW·h, coal at $53.10/MW·h and natural gas at $52.50.[67] Similar comparative results with natural gas were obtained in a governmental study in the UK in 2011.[68] Other sources in various studies have estimated wind to be more expensive than other sources. A 2009 study on wind power in Spain by Gabriel Calzada Alvarez Universidad Rey Juan Carlos concluded that each installed MW of wind power led to the loss of 4.27 jobs, by raising energy costs and driving away electricity-intensive businesses.[69] The U.S. Department of Energy found the study to be seriously flawed, and the conclusion unsupported.[70] The presence of wind energy, even when subsidised, can reduce costs for consumers (€5 billion/yr in Germany) by reducing the marginal price by minimising the use of expensive 'peaker plants'.[71]

The marginal cost of wind energy once a plant is constructed is usually less than 1 cent per kW·h.[72] In 2004, wind energy cost a fifth of what it did in the 1980s, and some expected that downward trend to continue as larger multi-megawatt turbines were mass-produced.[73] However, capital costs have increased. For example, in the United States, installed cost increased in 2009 to $2,120 per kilowatt of nameplate capacity, compared with $1,950 in 2008, a 9% increase.[74] Not as many facilities can produce large modern turbines and their towers and foundations, so constraints develop in the supply of turbines resulting in higher costs.[75]

Incentives

Some of the more than 6,000 wind turbines in the Altamont Pass Wind Farm, in California, United States. Developed during a period of tax incentives in the 1980s, this wind farm has more turbines than any other in the US.[76]

Wind energy in many jurisdictions receives financial or other support to encourage its development. Wind energy benefits from subsidies in many jurisdictions, either to increase its attractiveness, or to compensate for subsidies

77 received by other forms of production which have significant negative externalities.

In the US, wind power receives a tax credit for each kW·h produced; at 1.9 cents per kW·h in 2006, the credit has a yearly inflationary adjustment. Another tax benefit is accelerated depreciation. Many American states also provide incentives, such as exemption from property tax, mandated purchases, and additional markets for "green credits". Countries such as Canada and Germany also provide incentives for wind turbine construction, such as tax credits or minimum purchase prices for wind generation, with assured grid access (sometimes referred to as feed-in tariffs). These feed-in tariffs are typically set well above average electricity prices. The Energy Improvement and Extension Act of 2008 contains extensions of credits for wind, including microturbines.

Secondary market forces also provide incentives for businesses to use wind- generated power, even if there is a premium price for the electricity. For example, socially responsible manufacturers pay utility companies a premium that goes to subsidize and build new wind power infrastructure. Companies use wind-generated power, and in return they can claim that they are undertaking strong "green" efforts. In the US the organization Green-e monitors business compliance with these renewable energy credits.[77]

Full costs and lobbying

A House of Lords Select Committee report (2008) on renewable energy in the UK reported a "concern over the prospective role of wind generated and other intermittent sources of electricity in the UK, in the absence of a break-through in electricity storage technology or the integration of the UK grid with that of continental Europe".[78]

Commenting on the EU's 2020 renewable energy target, Helm is critical of how the costs of wind power are cited by lobbyists.[79] Helm also says that wind's problem of intermittent supply will probably lead to another dash-for-gas or dash-for-coal in Europe, possibly with a negative impact on energy security.[79]

In the US, the wind power industry has recently increased its lobbying efforts considerably, spending about $5 million in 2009 after years of relative obscurity in Washington.[80] By comparison, the US nuclear industry alone spent over $650 million on its lobbying efforts during a single ten year period ending in 2008.[81]

Environmental effects Main article: Environmental impact of wind power

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Livestock ignore wind turbines,[82] and continue to graze as they did before wind turbines were installed.

Compared to the environmental impact of traditional energy sources, the environmental impact of wind power is relatively minor. Wind power consumes no fuel, and emits no air pollution, unlike fossil fuel power sources. The energy consumed to manufacture and transport the materials used to build a wind power plant is equal to the new energy produced by the plant within a few months. While a wind farm may cover a large area of land, many land uses such as agriculture are compatible, with only small areas of turbine foundations and infrastructure made unavailable for use.[15]

There are reports of bird and bat mortality at wind turbines as there are around other artificial structures. The scale of the ecological impact may[83] or may not[84] be significant, depending on specific circumstances. Prevention and mitigation of wildlife fatalities, and protection of peat bogs,[85] affect the siting and operation of wind turbines.

A study on wind farm noise reported that people are annoyed by sound from wind turbines at far less sound levels than they are by noises from railroads, aircraft, or road traffic. The study found the percentage of respondents who found noise levels highly annoying rose quickly as sound levels increased above about 37dbA (about the level of a conversation). [86]

Small-scale wind power

This wind turbine charges a 12 V battery to run 12 V appliances.

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5 kilowatt Vertical axis wind turbine

Small-scale wind power is the name given to wind generation systems with the capacity to produce up to 50 kW of electrical power.[87] Isolated communities, that may otherwise rely on diesel generators may use wind turbines to displace diesel fuel consumption. Individuals may purchase these systems to reduce or eliminate their dependence on grid electricity for economic or other reasons, or to reduce their carbon footprint. Wind turbines have been used for household electricity generation in conjunction with battery storage over many decades in remote areas.

Grid-connected wind turbines may use grid energy storage, displacing purchased energy with local production when available. Off-grid system users can either adapt to intermittent power or use batteries, photovoltaic or diesel systems to supplement the wind turbine. Equipment such as parking meters or wireless Internet gateways may be powered by a wind turbine that charges a small battery, replacing the need for a connection to the power grid.

In locations near or around a group of high-rise buildings, wind shear generates areas of intense turbulence, especially at street-level.[88] The risks associated with mechanical or catastrophic failure have thus plagued urban wind development in densely populated areas,[89] rendering the costs of insuring urban wind systems prohibitive.[90] Moreover, quantifying the amount of wind in urban areas has been difficult, as little is known about the actual wind resources of towns and cities.[91]

A new Carbon Trust study into the potential of small-scale wind energy has found that small wind turbines could provide up to 1.5 terawatt hours (TW·h) per year of electricity (0.4% of total UK electricity consumption), saving 0.6 million tonnes of carbon dioxide (Mt CO2) emission savings. This is based on the assumption that 10% of households would install turbines at costs competitive with grid electricity, around 12 pence (US 19 cents) a kW·h.[92]

80 Distributed generation from renewable resources is increasing as a consequence of the increased awareness of climate change. The electronic interfaces required to connect renewable generation units with the utility system can include additional functions, such as the active filtering to enhance the power quality.[93]

Research and development

Despite growing worldwide demand for wind energy, present wind technology is not optimized and there are still significant challenges. Most of the research has occurred in industry, and is not always easily shared. According to a research agenda from from a coalition of researchers from universities, industry, and government, supported by the Atkinson Center for a Sustainable Future, wind energy research requires a drastic transformation. According to the report:

The gains that we are seeking require new innovations in fluid dynamics, control, materials, manufacturing, structures, and electric power distribution, as well of new ways of engaging the public in appreciating and accepting this technology, the associated transmission infrastructure and its effects on reducing climate change. Design and analysis tools need to be developed. Common computer codes need to be shared and refined in an open collegial way that cannot occur in industry. Researchers need to disseminate, debate, and share results openly, accelerating innovation in the subject

6 Wind energy has been the fastest growing source of energy since1990…

81

This dish/Stirling solar power system in Arizona is capable of producing 25 kW of electricity. Bill Timmerman, NREL/PIX08982 7 Hydrogen is high in energy, yet its use as a fuel produces water as the only emission. 1 or 2 MW. Large, utility-scale projects can have hundreds of turbines spread over many acres of land. Small turbines, below 50 kW, are used to charge batteries, electrify homes, pump water for farms and ranches, and power remote telecommunications equipment. Wind turbines can also be placed in the shallow water near a coastline if open land is limited, such as in Europe, and/or to take advantage of strong, offshore winds. Wind energy has been the fastest growing source of energy in the world since 1990, increasing at an average rate of over 25 percent per year. It’s a trend driven largely by dramatic improvements in wind technology. Currently, wind energy capacity amounts to about 2500 MW in the United States. Good wind areas, which cover 6 percent of the contiguous U.S. land area, could supply more than one and a half times the 1993 electricity consumption of the entire country. California now has the largest number of installed turbines. Many turbines are also being installed across the Great Plains, reaching from Montana east to Minnesota and south through Texas, to take advantage of its vast wind resource. North Dakota alone has enough wind to supply 36 percent of the total 1990 electricity consumption of the lower 48 states. Hawaii, Iowa, Minnesota, Oregon, Texas, Washington, Wisconsin, and Wyoming are among states where wind energy use is rapidly increasing.

Hydrogen Hydrogen is high in energy, yet its use as a fuel produces water as the only emission.

82 Hydrogen is the universe’s most abundant element and also its simplest. A hydrogen atom consists of only one proton and one electron. Despite its abundance and simplicity, it doesn’t occur naturally as a gas on the Earth. Today, industry produces more than 4 trillion cubic feet of hydrogen annually. Most of this hydrogen is produced through a process called reforming, which involves the application of heat to separate hydrogen from carbon. Researchers are developing highly efficient, advanced reformers to produce hydrogen from natural gas for what’s called Proton Exchange Membrane fuel cells. You can think of fuel cells as batteries that never lose their charge. Today, hydrogen fuel cells offer tremendous potential to produce electrical power for distributed energy systems and vehicles. In the future, hydrogen could join electricity as an important “energy carrier”: storing, moving, and delivering energy in a usable form to consumers. Renewable energy sources, like the sun, can’t produce energy all the time. But hydrogen can store the renewable energy produced until it’s needed. Eventually, researchers would like to directly produce hydrogen from water using solar, wind, and biomass and biological technologies.

Ocean Energy The ocean can produce two types of energy: thermal energy from the sun’s heat, and mechanical energy from the tides and waves. Ocean thermal energy can be used for many applications, including electricity generation. Electricity conversion systems use either the warm surface water or boil the seawater to turn a turbine, which activates a generator. The electricity conversion of both tidal and wave energy usually involves mechanical devices. A dam is typically used to convert tidal energy into electricity by forcing the water through turbines, activating a generator. Meanwhile, wave energy uses mechanical power to directly activate a generator, or to transfer to a working fluid, water, or air, which then drives a turbine/generator. Most of the research and development in ocean energy is happening in Europe.

The 6-MW Green Mountain power plant in Searsburg,

83 Vermont, consists of eleven 550-kW wind turbines. Green Mountain Power Corporation, NREL/PIX05768

NASA uses liquid hydrogen to launch its space shuttles and hydrogen fuel cells to provide them with electricity NASA, NREL/PIX03814 8 Resources The following are sources of additional information on renewable energy. The list is not exhaustive, nor does the mention of any resource constitute a recommendation or endorsement.

Ask an Energy Expert DOE’s Energy Efficiency and Renewable Energy Clearinghouse (EREC) P.O. Box 3048 Merrifield, VA 22116 Phone: 1-800-DOE-EREC (363-3732) TDD: 1-800-273-2957 Fax: (703) 893-0400 E-mail: [email protected] Online submittal form: www.eren.doe.gov/menus/ energyex.html Consumer Energy Information Web site: www.eren.doe. gov/consumerinfo/ Energy experts at EREC provide free general and technical information to the public on many topics and technologies pertaining to energy efficiency and renewable energy. DOE’s Energy Efficiency and Renewable Energy Network (EREN) Web site: www.eren.doe.gov Your comprehensive online resource for DOE’s energy efficiency and renewable energy information. Organizations

84 Center for Energy Efficiency and Renewable Energy (CEERT) 1100 Eleventh St., Suite 311 Sacramento, CA 95814 Phone (916) 442-7785; Fax (916) 447-2940 E-mail: [email protected] Web site: www.cleanpower.org Promotes the development of renewable energy technologies and resources. National Renewable Energy Laboratory (NREL) 1617 Cole Blvd. Golden, CO 80401 Web site: www.nrel.gov DOE-lab devoted to researching and developing renewable energy and energy efficiency technologies. Renewable Energy Policy Project (REPP) 1612 K St. NW, Suite 202 Washington, DC 20006 Phone: (202) 293-2898; Fax: (202) 293-5857 Web site: www.repp.org Works to advance renewable energy technologies. Web Sites CADDET Renewable Energy Web site: www.caddet-re.org Provides technical information on renewable energy projects and technologies from around the world. Clean Energy Basics NREL Web site: www.nrel.gov/clean_energy/ Provides basic information on renewable energy technologies, including specific links for homeowners, small business owners, students, and teachers. European Renewable Energy Exchange (EuroREX) Web site: www.eurorex.com Features information and news on renewable energy technology developments in Europe and around the world. Planet Energy—The Renewable Energy Trail United Kingdom Department of Trade and Industry Web site: www.dti.gov.uk/renewable/ed_pack/ index.html Specifically gears its information for students and teachers, from grade school through high school. Solstice

85 Center for Renewable Energy and Sustainable Technology (CREST) Web site: http://solstice.crest.org Provides an online source of information on renewable energy and technology development. Further Reading Achieving Energy Independence—One Step at a Time, J. Yago, Dunimis Technology, 1999, 190 pp. Charging Ahead: The Business of Renewable Energy and What It Means for America, J. Berger and L. Thurow, University of California Press, 1998, 416 pp. Clean Energy Choices: Tips on Buying and Using Renewable Energy at Home, DOE Office of Energy Efficiency and Renewable Energy, 2000, 48 pp. Print copy available from EREC (see “Ask an Energy Expert” above), and a PDF is available at www.nrel.gov/docs/fy00osti/ 27684.pdf. The Real Goods Solar Living Sourcebook: The Complete Guide to Renewable Energy Technologies and Sustainable Living, D. Pratt ed., Real Goods, 1999, 562 pp. References

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88 http://books.google.com/?id=k22YCjWjF60C&pg=PA14&dq=Al- Masjid+Al-Aqsa. 55. Meri and Bacharach, 2006, p.50 56. Masjid al-Aqsa: Second house of prayer established on Earth World Press. 57. Allen, Edgar (2004). States, Nations, and Borders: The Ethics of Making Boundaries. Cambridge University Press. ISBN 0521525756. http://books.google.com/?id=bntCSupRlO4C&pg=PA192&dq=Al- Masjid+Al-Aqsa. Retrieved 9 June 2008 58. Shah, 2008, p.39. 59. Asali, 1990, p.105. 60. Mosaad, Mohamed. Bayt al-Maqdis: An Islamic Perspective pp.3–8 61. The Furthest Mosque, The History of Al - Aqsa Mosque From Earliest Times Mustaqim Islamic Art & Literature. 5 January 2008.

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