for County Facilities

Many regional utilities offer credit on ener- A dish engine system is essentially an elec- ●●Introduction gy bills for providing the utility with excess tric generator that runs on . A dish involves the use of the sun’s electricity from the customer’s solar or other made of glass mirrors collects direct rays of energy to provide electricity, heat, or light. alternative energy electricity system. This light from the sun and concentrates these rays This energy can be harnessed for use in both “net energy metering” can lead to significant in a receiver. The receiver converts it to heat large- and small-scale projects, from a home bill reductions for customers with this tech- and then transfers it to the engine, which uses to a commercial building. According to the nology. it to produce electricity. This is essentially an NACo County Green Programs Survey, electric generator that runs on sunlight. Environmentally, the use of solar energy which was sent to counties nationwide in benefits both land and air quality. Solar pow- June 2008, 14% of the 147 respondents gen- Some concentrating solar systems are com- er does not create gas emissions, erate . Of this renewable bined with thermal storage capacities to op- nor does it release other toxins into the air. energy, 40% is solar power. erate during nighttime. Others are combined It also replaces the use of fossil fuels with a with natural gas powered generators, so that Sunlight is made of photons, which contain renewable resource. power can be produced on demand if needed. energy. Several technologies have emerged In both cases, the reason is to ensure power to harness this energy including concentrat- ●●Concentrating Solar can be produced on demand even if the sun ing solar power, , solar heating is not shining. and solar , all of which will be ex- Power Systems plained in this fact sheet. By using mirrors or lenses to concentrate Concentrating solar power systems may the rays of the sun, solar thermal systems can also use special photovoltaic cells (see the ●●Costs and Benefits produce temperatures as high as 750 degrees section on Photovoltaic Systems below) de- Fahrenheit. DOE reports that this intense signed for the intense light from the concen- The sun shines daily, serving as a con- heat can produce anywhere from 10 kilo- trator. However, these types of collectors are stant free fuel. The U.S. Department of En- watts to 100 megawatts of electricity. Solar mostly under development and not commer- ergy (DOE) reports that even on extremely concentrators come in three main designs: cially available. overcast days, solar energy systems can still parabolic troughs, power towers, and dish Boulder County, Colorado is working to produce 25% of maximum output, and this engine systems. Arrays of lenses are also oc- identify potential sites for concentrating so- number increases to as much as 80% on days casionally used. lar power plants, as well as finding partners that are only partially cloudy. Due to this to support and demonstrate these projects. abundantly available fuel, solar power can be The uses a curved collec- The county has created a map with possible a cost-effective choice. Note: Regional dif- tor to reflect light onto a pipe running along areas for these plants. The county is also ferences (particularly weather patterns) may the inside of the curved surface. This raises encouraging a company with plants in the make another source of energy more cost ef- the temperature of a heat transfer fluid in the county, Frito Lay, to build 50 acres of solar fective. pipe, which then is used to run a steam gen- erator. Often, these troughs will be combined concentrators to provide renewable fuel. This to create a collector field, which is generally plan would reduce the plant’s electricity con- aligned on a north-south axis, in order to op- sumption by 90% and the use of natural gas timize the sun as it travels across the sky. by 80%. For more information, see the Boul- der County sustainability website, located at According to the Union of Concerned Sci- www.bouldercounty.org/sustain/. entists, a nonprofit organization working for a healthy world, there are currently nine so- lar electric generating stations in California’s Mojave Desert, built from 1985 to 1991. Power towers concentrate sunlight from a very large area on a receiver at the top of a tower. The sunlight is reflected by , large sun-tracking mirrors that all point the sunlight at the tower. Inside the tower the receiver contains a heat-transfer fluid which then generates steam power to drive turbines, producing electricity. The system was in- County Case Study: stalled in the county’s youth center, home Washtenaw County, Michigan to 30 people. Hot water at the facility is Population: 341,847 used for 30 showers daily, laundry, and in County Seat: Ann Arbor the kitchen. The system consists of a flat- plate solar collector and a storage tank. It Washtenaw County, Michigan has a allows the facility to save $500 and 400 photovoltaic and solar hot water heating cubic feet of natural gas each year, as well system in two county facilities. The 10 as to reduce carbon dioxide emissions by kilowatt , installed at 5,000 annually. the Washtenaw County Western Service Center, generates enough power for 3% The county also educates the community to 5% of the facility’s energy needs, sav- about solar power. The Washtenaw County ing the county $1,000 to $1,500 annually Western Service Center features a display and reducing carbon dioxide emissions by with information about the county’s solar 16,000 to 24,000 pounds. It was funded by power use, as well as a computer with real a grant from the Energy Office of the State time data about energy production and the ●●Photovoltaic Systems of Michigan. money that using solar power is saving the Photovoltaic systems convert solar energy county. into electricity. The use of these systems in the U.S. is rapidly increasing. Solar Industry Magazine reports that the number of new sys- in remote locations where no utility power is In May 2004, Butte County, California tems in the U.S. approached 13,000 in 2007, available. commissioned Sun Power & Geothermal up 24% from the previous year, bringing the Energy in collaboration with Sharp Electron- A more common solution is to connect cumulative number to over 48,000 locations. ics Corporation, Pacific Gas & Electric, and the photovoltaic system to the utility power Methods of collecting and storing solar en- the California Energy Commission, to install grid with equipment that outputs utility- ergy vary depending on the intended uses. a solar energy system that would double the compatible power, while protecting both the solar energy already produced in the county. Most commercial photovoltaic “cells” (also utility and photovoltaic systems in case of Installation was completed in September called solar cells), are made of silicon, which problems on either side. When the sun does 2004, with a total project cost of just over is a semiconductor, allowing it to absorb not produce sufficient energy for the facil- $8.4 million. some sunlight and convert it into electricity. ity, electricity can come from a local power The silicon in a is very specially company. In addition, with the company’s The system is comprised of four separate formulated and manufactured so that it will approval, the facility may also be able to sell solar arrays, providing all power for three allow energy to move through it, producing excess power generated by the solar cells to electricity. the power company. Sunlight is made of photons, which contain The typical amount of time that it takes for energy. When these photons hit the photovol- a photovoltaic system to generate the same taic cell, some are absorbed, and the energy amount of energy that it took to create the from the photon is transferred to an electron system is about 2 to 5 years. A well-designed, in an atom in the cell. The electron uses this well-cared-for system can last for 20 or more energy to move around freely, becoming part years, creating a net energy gain. of the electric current. A metal backing and a grid of wires on the front collects the elec- According to the Florida Solar Energy tricity and connects it to the power system. Center, the state’s energy research institute, The photovoltaic cell is also covered with an non-tracking solar arrays (that do not follow anti-reflective coating to prevent loss of pho- the sun’s path) located in the Northern Hemi- tons. Finally, a glass cover plate covers the sphere should face south in order to best col- cell to protect it from the elements. lect sunlight. Additionally, they should be inclined at an angle equal to 90% of their lo- Of course, the sun does not constantly shine cation’s latitude, so as to receive as much en- in one place. One solution for this is to install ergy as possible year-round. They should be deep-cycle batteries to store energy for night- placed away from shade. If even one of the time. These batteries are charged during the cells in the panel is shaded, the production day, and are able to discharge a current for a of power can be reduced by more than 50%. long period of time over the night or cloudy Furthermore, the panels should be designed periods when more electricity is needed. to account for the time of year with the worst Typically, however, batteries are an expen- weather, so as to ensure that enough electric- sive and high-maintenance option, so are ity can be produced year-round. rarely used for solar electric systems except county government buildings and producing lated and glazed box through which cold tem can consist of a passive system, an active approximately one peak megawatt of power. water passes to be heated; or system, or a combination of both. When commissioned, it was the fifth largest zzevacuated tube solar collector systems: Passive systems are usually less costly and such system in the U.S. and the seventeenth rows of metal absorber tubes are sur- less complex than active systems, but both largest in the world. Monitoring kiosks were rounded by a transparent glass outer tube can be used to control the building tempera- placed in public locations for real-time view- with the air removed, to reduce heat loss. tures. According to the DOE, it is most eco- ing of solar energy production information. Each metal tube has a fin whose coating nomical to design a system that will produce Working together with Kennecott Land, absorbs solar energy. 40% to 60% of the heat for the building. Rocky Mountain Power, the Salt Lake City There are two types of active solar water Therefore, the structure should have a back- Corporation, and Utah Clean Energy, Salt heating systems. Direct circulation systems up heating system to provide the rest of the Lake County, Utah is developing a plan to pump the water directly through the collec- heat, as well as for cloudy days. facilitate the installation of at least 10 mega- tors described above, then into the building There are two kinds of active heating sys- watts of photovoltaic systems before 2015. for use. Indirect circulation, on the other tems, liquid and air. In a liquid-based system, These partners are identifying barriers to the hand, pumps heat-transfer fluid through the water or anti-freeze moves through the col- use of solar energy, creating a comprehensive collectors, then through heat exchangers, lector and absorbs solar heat, then travels to plan, and partnering with land developers to which is used to heat the water that flows a storage tank or heat exchanger to transfer install solar energy in new housing develop- into the building. the heat to a distribution fluid. The collectors ments. Bexar County, Texas has installed a solar work the same way as described above for Cook County, Illinois commissioned the water heater in the county’s Adult Detention solar water heaters. Spire Corporation to design and build a pho- Annex. The water heater has a 30,000 gallon After the liquid is heated, it can be used to tovoltaic array for the county’s Domestic capacity and is capable of heating 500,000 distribute heat in any of the following ways: Violence Courthouse. The system produces gallons each month to temperatures of up 129,640 kilowatt-hours of electricity annu- to 140 degrees. The system initially cost zzradiant floor heating: the room is heated ally, making it the largest single system in $495,000; however, operating costs are only by liquid traveling through pipes in a thin the area. It will provide more than 5% of the $2,600 each year, which is $76,168 less than concrete slab in the floor; building’s energy needs. the annual costs of a conventional system. zzhot water baseboards or radiators: fluids The county estimates that the project will are distributed to appliances that heat the The array was funded by a combination of have paid for itself within 4.9 years. county funds, money from the utility com- room; or pany, and a grant from the Illinois Clean En- Solar Building Heating Systems zzcentral forced air system: air is passed over the heated liquid, warming it, and ergy Community Foundation. Solar heating requires almost no energy then returned to the room. transformation, and therefore is an efficient ●●Solar Heating use of solar power. A solar space-heating sys- In an air-based collection system, the air is According to the U.S. Environmental Pro- tection Agency’s (USEPA) ENERGY STAR program, commercial buildings across the country use almost 35% of energy for space heating. Additionally, the DOE reports that water heating comprises up to 17% of resi- dential energy consumption and significant percentages (varying depending on industry) in commercial buildings. Solar water and space heating can reduce the use of outside energy. Solar Water Heating Solar water heaters require a well-insulated storage tank and a conventional water heater as back up. There are three kinds of solar col- lection systems used to heat water: flat plate, integral collector-storage, and evacuated tube solar collectors. zzthe flat plate system: a dark absorber plate, sometimes under a glass or plastic cover, is placed in an insulated weather-proofed box on the roof in a sunny location; zzthe integral collector-storage system: black tanks or tubes are placed in an insu- amount of solar energy received as the sun County Case Study: moves across the sky. The array, located in Dane County, Wisconsin the flamingo pen, is capable of producing Population: 458,106 1,950 kilowatt hours each year. County Seat: Madison Additionally, the Dane County Justice Dane County, Wisconsin has two main Center was the first building to be con- photovoltaic projects: one at the Dane structed under the county’s County Arena, the other at the Henry Vilas Policy. The nine-story, $44 million project Zoo. incorporated concepts into its design, using the results of the county’s The Arena is powered by a fixed-panel, analysis on the site to determine how to roof-mounted photovoltaic system, in- maximize natural light while minimizing stalled in 2000. The system consists of 16 heat and glare. The facility has traditional panels, each 4 feet by 6 feet. It is capable of heated in a collector, which can take one of sidelight and clerestory windows, some of producing 5,612 kilowatt-hours each year, the following forms: which have an exterior sun shade, and the greatly reducing the energy bills for the building has been designed to save 50% of zzan airtight, insulated metal frame, with a 20,000 square foot Arena. black metal plate to absorb heat: The so- electricity consumption and $96,500 in an- lar radiation heats the plate, which in turn The Henry Vilas Zoo has a dual-axis track- nual costs. heats the air in the collector. This air is ing array that allows it to maximize the then blown back into the room; or zza dark metal plate with holes in it attached to the south-facing wall, leaving air space between the wall and this cover. The plate are designed to collect, store, and then dis- There are three kinds of passive solar heat- heats up, and a fan or blower draws air tribute it. An aperture, or collector, is a large ing systems: direct gain, indirect gain, and into the building through the holes in the glass window through which the sunlight en- isolated gain. A direct gain system is the sim- collector and then through the air space, ters the building. The absorber, collects the plest of the three. The sunlight first passes which is warmed by the hot metal plate. heat from the sun and stores it in the thermal through south-facing windows, after which mass. This is often made of it hits masonry walls or floors. The masonry Air-based heating systems produce heat masonry, although sometimes water is used absorbs the heat and later, when the room at earlier and later times in the day than do instead. During the evenings, when it be- cools, radiates it into the room. liquid systems, and they also do not freeze. comes colder, the heat is released; in a purely However, air is less efficient at transferring Indirect gain systems involve an 8 to 16 passive system, this heat moves through the heat than is liquid. inch thick masonry wall built on the south building by the processes of conduction, side of the building. Glass is mounted an inch Passive solar heating does not require convection, and radiation; however, a fan is in front of this wall, and the heat is stored pumps or electrical controls to transfer the sometimes also used. between the window and the wall. After the heat, because the windows, walls, and floors heat is absorbed into the wall, it then radiates through into the living space. This is often referred to as a Trombe wall. Isolated gain systems involve a sunspace, more commonly known as a solar room or solarium. Vertical windows are installed around the room with a masonry floor, ma- sonry walls, or water container to absorb heat from the sun. Later, the heat is circulated to the rest of the building through ceiling and floor vents, windows, or fans. San Mateo County, California’s Office of Education demonstrated alternative build- ing methods by constructing a building out of straw bales. The building maintains a con- stant inside temperature of 60 to 75 degrees Fahrenheit (despite outside temperatures of 29 to 85 degrees Fahrenheit) by incorporat- ing elements of passive solar design. These include site orientation, double-paned win- dows, overhangs, and a cement slab floor which serves as the thermal mass. The county is also in the process of in- County Case Study: stalling solar panels on the Media Bor- Delaware County, Pennsylvania ough Public Library and Elementary Population: 555,648 School. This project is partially funded by County Seat: Media a $94,245 grant from the Pennsylvania En- ergy Harvest Grant Program, and will pro- Delaware County, Pennsylvania currently duce 33,250 kilowatt-hours of electricity uses photovoltaic panels installed on the each year, saving the county at least $4,500 Veteran’s Museum. These produce 5,000 annually. It will also prevent 86,958 pounds kilowatt-hours each year and reduce the of carbon dioxide emissions, 120 pounds of building’s energy bill by 20%. Additionally, nitrogen oxide, and 476 pounds of sulfur they prevent the emission of 12,000 pounds oxide and mercury. The county also intends of carbon dioxide, 14 pounds of nitrogen to install photovoltaic panels at the commu- oxide, and 68 pounds of sulfur dioxide. nity theatre. ●●Solar Lighting According to the USEPA’s ENERGY STAR Indoor Lighting zzclerestories: apertures set high in the program, lighting is responsible for about walls. 13% of energy consumption in commer- Indoor lighting refers to daylighting, which cial buildings. Solar lighting can reduce the is essentially the strategic positioning of ap- Daylighting is most effective in buildings amount of power that facilities need to obtain ertures, or openings, to allow sunlight into used primarily during the day, but still re- from outside sources. the facility. This serves a dual purpose, both quires integration with a traditional lighting reducing the need for artificial light during system for times when there is not enough Outdoor Lighting the daytime as well as offering a view of the available sunlight. A daylighting system outside world. Outdoor solar lights consist of a plastic case, should incorporate sensors that turn off or dim artificial lights in response to the amount a solar cell, a rechargeable battery, a control- When placing the apertures, consider out- of natural light entering the building, so as to ler board, a light emitting diode (LED) light, side obstructions that could block the path of maintain lighting levels. and a photoresistor that is used to detect dark- sunlight or increase glare. Additionally, ar- ness. The battery is wired to the solar cells to range the facility so that tasks which need the Clackamas High School in Clackamas allow the charging of the battery during the most light are conducted near the aperture. County, Oregon, incorporates daylighting day. When it is completely charged, the bat- techniques into the building design. The fa- The DOE reports that the window will light tery can power the light for approximately 15 cility was oriented to take advantage of opti- an area up to 1.5 times its height, but that this hours. At night, the photoresistor detects the mal daylighting and has windows, , number can be increased by using reflectors. absence of light and turns on the LED. and sunshades so that students and staff can These reflectors can include overhangs as have views and natural lighting. Approxi- It is important to remember that operating well as reflection from the walls, ceilings, mately 90% of occupied spaces are lit using times during the winter may be decreased and floor surfaces, which should be coated daylight, and the school saves 44% of energy because there are fewer hours of daylight for in high reflectance matte paint or tiles. Using through the use of this system. the battery to charge. Additionally, the cells light colored materials in the facility will also need to be placed in an area where they are increase the reflection of light. Additionally, not shaded by trees, the surrounding land- the higher the window, the more area of the scape, or other objects. room it will light. King County, Washington has installed 102 Sometimes, daylight will provide exces- solar-powered light emitting diode (LED) sive contrast or brightness. To prevent these systems in bus shelters since 2004. It cost problems, windows should be equipped with the county less to install the lights than to run shades, blinds, or drapes. Trees, plants, win- wires for electricity to the shelters and there dow glazings, shades, and screens can also is no monthly electrical bill; additionally, the be used to diffuse light. LED lights require less of the solar electricity than would incandescent bulbs, as they are Types of apertures used for daylighting in- more energy efficient. clude the following: zz In 2006 and 2007, the county also installed windows: apertures set at mid-level or 150 iStops. These are bus stops that al- lower in the walls; low customers to push a button, lighting a zzskylights: horizontal apertures in the solar-powered lamp. The county hopes that roof; this will better allow transit operators to see zzroof monitors: sections of the roof that passengers waiting at bus stops, preventing is raised above the rest of the roof, with buses from passing riders by in the dark. vertical glazing around the gap, allowing light to enter; and the amount of solar light each building County Case Study: received. All swimming pools must be Pima County, Arizona heated by solar energy. Population: 924,786 zzGreater Tucson Coalition for Solar En- County Seat: Tucson ergy: Since its start in 1997, the Coali- Pima County, Arizona has joined forces tion has raised close to $4 million for with the city of Tucson to form the Tucson- the development of solar energy, and Pima Metropolitan Energy Commission has seen a 400% increase in the number (MEC). The Commission, consisting en- of solar energy systems installed since tirely of volunteers, has set a goal to serve 2001. Additionally, the coalition helped “as a catalyst for the City of Tucson and develop 120 new solar energy industry Pima County to build a more sustainable jobs in 2003. future in the region.” To accomplish this, zzThe annual Solar Energy Home Tour: the MEC has created several programs in The tour allows people to visit solar the region. installations in more than 15 homes in the area. Participants are given the op- zz ●●Regulations for Solar The “solar village” Community of Civa- portunity to speak with the owners, de- Energy Systems no: The buildings’ roofs in the commu- signers, and builders of these residences, nity are required to be built to be able to and learn how to make their own homes It should be noted that it is necessary to support solar equipment, and all struc- more efficient and incorporate solar en- check local building codes and zoning laws tures in the community are required to ergy principles. before constructing a solar energy system. use some application of solar energy, The DOE lists the following problems that whether passive or active. The commu- For more information on the Tucson-Pima those installing solar energy systems often nity was planned and built to maximize Metropolitan Energy Commission, visit encounter: www.tucsonmec.org/. zzexceeding roof load; zzunacceptable heat changers; to house the largest solar power facility in If the county has sufficient access to fund- zzimproper wiring; the state. The land is now covered by 1,200 ing and has investigated all possible legal is- zzunlawful tampering with potable water photovoltaic panels mounted at ground level, sues, solar energy can be an excellent way to supplies; capable of producing 250 kilowatt-hours of save money and the environment. zzobstructing sideyards; energy each year. This prevents over 654,000 pounds of carbon dioxide from entering the zzerecting unlawful roof protrusions; and ●●Encouraging Use of atmosphere annually. zzsiting the system too close to streets or lot Solar Energy boundaries. The panels were installed by Florida Power Counties may to educate their residents For example, Coconino County, Arizona and Light, which provides a voluntary solar about the benefits of solar power by distrib- has developed specific codes for solar instal- power program to energy consumers in the uting brochures, hosting county events, put- lations. Any battery storage sheds for the so- area. The new array, dedicated in February ting information in the county website, or lar energy system require a permit, and those 2008, is capable of powering 55 homes. even putting an article in the newspaper, or attached to a residence must be built out of Zoning laws can also work in favor of can provide incentives. fire-resistant materials. The shed must be ad- those using solar energy. California’s Civil Montgomery County, Maryland has cre- equately ventilated. Additionally, metal ped- Code, section 801.5, describes a solar ease- ated a fact sheet to educate residents about estals supporting photovoltaic panels must ment, which is the right of receiving sunlight solar power. This information explains how be placed on concrete pilon footings 8 inches on land for use in a solar energy system. In the sun provides energy, how this energy is wide by 30 inches deep. When the panels are order to receive a solar easement, the appli- harnessed, and the benefits of its use. Addi- on the roof, the roof must be specifically de- cant needs to describe the dimensions of the tionally, the fact sheet provides information signed to support this amount of weight. easement in measurable quantities, such as about how to get started with solar energy. Sarasota County, Florida donated more degrees, as well as the necessary restrictions Some counties give tours of solar and green than 28,000 square feet, about half of the that would need to be placed on vegetation, homes. Other counties provide a series of size of a football field, in Rothenbach Park buildings, or other objects.

Visit www.greencounties.org educational workshops. For thirteen years, Counties can also use incentives to encour- Incentives can also encourage companies to Boulder County, Colorado has been hosting age local businesses and residents to start us- locate their solar technology in certain coun- the Boulder County Solar & Green Homes ing solar energy. ties. Davidson County, North Carolina has Expo and Evening Workshops. These teach proved $2 million in incentives to fund the Marin County, California offers rebates to residents and business owners how to in- construction of a photovoltaic array in the residents and local businesses in the unin- corporate renewable energy. A tour of over county. The array will be built by SunEdison, corporated part of the county, as well as to a dozen solar homes is also provided. Dur- and Duke Energy will buy 16 megawatts of county employees, regardless of the location ing this tour, participants are given the op- power from the new solar farm, beginning no for their residence, that have incorporated portunity to talk with owners, builders, con- later than 2010. solar power. Each household/business is eli- tractors, and installers, and to learn that solar gible for one rebate per solar power type. Eli- In 2005, the Miami-Dade County, Florida homes can be comfortable, reliable, afford- gible solar technology includes photovoltaic Board of Commissioners passed an ordi- able, and practical. systems ($500), solar domestic water heaters nance to encourage manufacturers of solar Arlington County, Virginia’s Fresh AIRE ($300), and solar pool heaters ($200). energy equipment to relocate to the county. (Arlington Initiative to Reduce Emissions) These companies may apply for incentives, Montgomery County, Maryland also pro- campaign has green suggestions on its web- funded through the county’s Targeted Jobs vides a Clean Energy Rewards program as site. These include information about buying Incentive Fund Program. Eligible compa- an incentive to buy environmentally-friendly solar-powered energy from local electricity nies are those that are planning to relocate energy, including solar, wind, and biomass. providers, as well as examples of how coun- to the county, or those already in the county Customers who purchase clean energy from ty residents are incorporating solar and other planning to expand. If the company manu- their utility providers receive a credit on their green technology into their own lifestyles. factures, installs, or repairs solar thermal or energy bill from the program. The county re- For more information on the Arlington Fresh photovoltaic systems, it is eligible for $1,500 imburses the energy suppliers for the rewards AIRE program, visit www.arlingtonva.us/ per new job created, up to $3,000 annually. that they pay to customers. climate. 6% less than what it is paying for electricity County Case Study: now, a savings of $5,000 the first year, and Multnomah County, Oregon possibly more in subsequent years as en- Population: 672,906 ergy prices rise. At the end of the 20 years, County Seat: Portland the county will own the system. Multnomah County, Oregon has signed At least five county buildings will receive a contract with Sun Edison, LLC to install solar panels, generating about a million solar panels on the roofs of county build- kilowatts of solar electricity each year. This ings. Sun Edison, LLC will build, own, is 2% to 3% of the total county energy use. and operate the photovoltaic systems, with This will reduce the county’s greenhouse help from federal grants, for 20 years. Dur- gas emissions by 700 tons annually. Three ing this time, the county will buy the solar- of these solar-powered systems should be powered electricity from the company for operating by the end of 2008.

conservation efforts in county buildings. complished by installing solar panels on the ●●Funding for Solar These included a multi-year program of roofs of city and county facilities, and will Energy solar-powered projects. The county is also provide 10 to 12 megawatts of solar power. Solar systems do require a significant up- working to educate businesses and residents front cost to design and install. Funding about reducing greenhouse gas emissions Performance Contracting sources to install the technology can include and promoting . In performance contracting, a private busi- allocating county funds, issuing bonds, third- ness creates a contract with the county to in- party financing, lease-purchase agreements, Bonds vest in energy retrofits. The business pays for or receiving grants or loans. Bonds are very similar to loans, but are the system, and the county shares profits with more complex. A general obligation bond the contractor. For more information on per- Allocating County Funds requires a referendum of county residents; a formance contracting, see the NACo Green When allocating county funds from the bud- revenue bond system is initiated in anticipa- Government fact sheet on “County Build- get, the county remains able to control the tion of future savings from the project that ings: Energy Efficiency and Performance solar system and its installation completely. they would finance. Contracting,” available at www.greencoun- ties.org. However, this method often will not yield as In a referendum, 73% of residents San Fran- much money as would be obtained through cisco County, California voted in favor of Working with Siemens’s Building Technol- other means. bond measures to fund a $100 million instal- ogies, a 100-killowatt solar array was placed Arlington County, Virginia allocated $1.5 lation of solar power, , and other on the Health and Human Services building million in its Fiscal Year 2008 budget for energy efficient technology. This will be ac- in Sacramento County, California. The solar energy system offsets the electricity used by the facility by nearly 50%. Not only will this help save the county and taxpayers money on their energy bill every month, it also qualifies for than $300,000 in rebates from the Sacramento Municipal Util- ity District (SMUD) as part of a rebate pro- gram designed to encourage consumers and state and local agencies to invest in energy- saving technologies. Sacramento County averages about 265 days each year that are either clear or partly cloudy, allowing the system access to the sun’s rays. This can help to reduce over 800 metric tons of greenhouse gas emissions. Lease-Purchase Agreements A lease-purchase agreement involves the provision of solar equipment for a facility by a private business. The county makes pay- ments on this equipment, or for the energy produced by the equipment, using the money its saves by using solar power. At the end of zzIncident light- light shining onto the ●●Common Solar face of the solar cell. Terms zzPhoton- a light particle acting as an in- zzAntireflection coating- this is a thin dividual energy unit. coating that is applied to the surface of a zzPhotovoltaic array- a collection of pho- solar cell to reduce light reflection. tovoltaic modules that function together zzAperture- the opening in the roof or to produce electricity. wall to allow daylighting. There are zzPhotovoltaic cell (or solar cell)- a two types of apertures; sidelighting (ap- semiconductor element in a photovoltaic ertures on the side of the building) and module that converts light into electrical toplighting (apertures on the top of the energy. building). zzPhotovoltaic module- an assembly zzDeep discharge battery- a battery dis- of solar cells to generate direct current charged to 20% or less of the full charge power under sunlight. capacity. the lease agreement, the county may choose zzPhotovoltaic panel- connected photo- zzElectron- a particle in an atom with a to keep the equipment. voltaic modules. negative electrical charge; its movement Solano County, California has signed an creates an electric current. agreement with Honeywell, International to purchase solar power for 20 years. This will be accomplished by the installation of solar The Santa Rita Jail in Alameda County, panels on bus ports near the Claybank Adult California, is topped by a three-acre solar ar- Detention Facility, which will be powered by ray on its roof. Originally the array, installed this array. The project is projected to gener- in 2001, generated only 640 kilowatts; how- ate almost over a million kilowatt-hours of ever, the project was so successful that the electricity and the save the county $1 million county expanded it a year later. The new ar- in energy each year. This solar power will ray now produces 1.2 megawatts of power, meet almost two-thirds of the facility’s en- and has reduced the peak summer demand of ergy needs and reduce carbon dioxide emis- traditional electricity by 35%. sions by over 14,500 metric tons during the duration of the contract. The project was funded by a combination of a low interest loan from the California After the 20-year contract is completed, the Energy Commission’s Emerging Renewable county will have the option to continue buy- Buydown Program and incentives from the ing the solar-generated electricity or to buy California Utilities Commission. The project the solar array itself. This will be the third saved the county $425,000 in the first year, solar electric facility in Solano County. and is projected to save $15 million during its life. Grants and Loans Borrowing money from commercial banks, Additionally, programs at both the state and pension funds, insurance companies or other federal level contribute funding to assist lo- financial institutions allows the county to cal governments to install solar power sys- obtain financing for the project without allo- tems. There are several of these programs in cating money from other recipients of county existence; examples include the California funds. However, interest still has to be paid Solar Initiative (CSI) and the U.S. Depart- on the borrowed money and the county is ment of Agriculture (USDA) Rural Energy responsible for repaying the debt even if the for America Program (REAP), which are ex- savings are not as high as anticipated. plained below. In order to fund its solar energy project in zzCalifornia Solar Initiative: As part of its 2004, Butte County, California borrowed Million Solar Roofs Program, the state of $3.2 million from the California Energy California has set a goal to create 3,000 Commission and $1 million from the Butte megawatts of solar-powered electricity by County Investment Pool at a 3.95% interest the year 2017. To achieve this objective, rate. By making payments of $313,000 each the California Public Utilities Commis- year, this money will be repaid in 13.2 years. sion will provide $2.2 billion in incentives The cost savings from the system were about over the next decade. These incentives in- $317,000 in 2004 and it is estimated that over clude $2.50 per watt for systems up to one the course of 40 years, the net savings after megawatt. Additionally, California has the repayment of loans will be $8.5 million. ordered each municipal utility to offer a solar incentive program to customers. For Hybrid solar lighting is a combination of Solar Hydrogen Energy Corporation more information on the California Solar electrical and solar light fixtures in which a (SHEC) has created a system to produce Initiative, visit www.gosolarcalifornia. concentrator is mounted on the roof to collect hydrogen from landfill gases, using solar ca.gov/csi/. sunlight, which is then funneled through op- power. In this system, methane and carbon zzUSDA Rural Energy for America Pro- tical fibers into the building. In the building, dioxide, landfill gases, are fed into a reactor, gram: This program provides grants and the light goes to a hybrid light fixture, which heated by a concentrating solar energy sys- loan guarantees to purchase renewable is equipped to use both sunlight and artificial tem. The gases are reacted, forming hydro- energy systems and make improvements light. Sensors raise and lower the necessary gen and carbon monoxide. These gases then in energy efficiency. Several types of re- level of electrical light as the amount of sun- go into a water gas shift reactor, resulting in newable energy are eligible for the pro- light varies throughout the day. hydrogen and carbon dioxide. gram, including solar water heat, solar No energy conversion is necessary for these SHEC has already built one solar-hydro- space heat, solar thermal electric, and fixtures; the solar light is sent directly to the gen-from-landfill-gas production station in photovoltaics. Grants offered may be up light fixtures. Additionally, some hybrid light the city of Regina Saskatchewan, Canada. to 25% of the program’s cost, while loan fixtures also create solar-powered electricity This plant is estimated to produce 1.2 mil- guarantees may be up to $25 million, as from the invisible sun rays that cannot be lion kilograms of renewable hydrogen annu- long as the combined amount of the grant used for lighting. ally. SHEC hopes to construct these plants in and loan guarantee is not higher than 75% other locations, as well. of the project’s cost. For more information Several solar-powered vehicles have al- on REAP, visit www.rurdev.usda.gov/rbs/ ready been designed. Each year, the North farmbill/. American Solar Challenge encourages com- ●●Conclusion These are only a few examples of the many petitors to build solar-powered cars in a race The use of solar technology is increasing programs in existence today. For a compre- from Dallas, Texas to Calgary, Alberta. At quickly throughout the country with the use hensive database of state and federal energy this point, many of the designers of solar- of solar lighting techniques, solar water heat- incentives, visit www.dsireusa.org. powered cars are research departments at ing, solar space heating, and solar powered universities. electricity. Solar energy provides an econom- ●●Emerging Solar For a solar car to function, solar cells on the ically-competitive source for energy. Technologies car would have to collect the sunlight and Counties are tapping into the resources pro- turn it into electricity. Some of this electric- vided for solar energy and to great success. Solar power continues to change and de- ity would be stored in a battery for use when By facilitating solar energy use, counties can velop as new technology emerges, and the no sunlight is available. However, the car reduce cost and prevent harmful greenhouse future looks bright for the implementation of would have to be designed very efficiently gas emissions. As researchers continue to this new technology, including hybrid solar to contain enough solar cells to provide the investigate the uses of harnessing the sun’s lights, solar-powered vehicles, and solar hy- necessary power. power, new technology increases, and solar drogen produced from landfill gas. power becomes more and more a common part of daily life, benefiting both counties, taxpayers, and the environment. Member companies of the NACo Green Government Initiative can batteries that have a long operating cycle, have high charge accep- help you with your green commercial building needs. tance, recharge well, and require almost no maintenance. zzConstellation Energy zzNORESCO Constellation Energy uses its experience in renewable technolo- NORESCO works to bring the company’s expertise into designing, gies, including solar, biomass, and geothermal energy, to fulfill its building, financing, owning, managing, and operating central energy contract for energy performance contracting in the state of Mary- facilities, including those using photovoltaics. land. The company identifies cost-saving energy solutions that are friendly to the environment for their clients. In 2007, Constellation zzSiemens Energy received the 2007 Green Power Leadership award from the Siemens has installed more than a megawatt of solar PV power in DOE. the last year. The company offers a full array of renewable energy solutions across the country, including landfill gas-to-energy, bio- zzGeneral Motors mass and wastewater treatment-to-energy. Siemens also performs General Motors uses solar energy to partially power two of its fa- investment grade energy audits which identify inefficiencies and cilities. The company has installed photovoltaic arrays on the roofs recommend energy-saving measures and retrofits. of warehouses in Cucamonga, California, and Fontana, California, which generate up to 1.5 million kilowatts and 1.3 million kilowatts zzWal-Mart of energy each year, respectively. This powers about half the build- Wal-Mart has been piloting a program to use solar energy in its ing’s energy needs, and the warehouse in Fontana is estimated to facilities. So far, 22 Wal-Mart stores, Sam’s Clubs, and distribution create and send enough power back to the electrical grid to power centers in the states of Hawaii and California use solar power. Each 200 homes. facility’s generating system can provide up to 30% of the power for the store on which it is installed, and Wal-Mart expects to reduce zzJohnson Controls greenhouse gas emissions by 8,000 to 10,000 metric tons each year. Johnson Controls sells solar kits designed to help show customers how solar power can help them save money. These kits include solar

●● zzFlorida Solar Energy Center Additional Resources www.fsec.ucf.edu/en/ zzAmerican Solar Energy Society The Florida Solar Energy Center was created in 1975 by the Florida www.ases.org/ Legislature to conduct research, as well as test and develop energy The American Solar Energy Society is a nonprofit organization that technology that will enhance the economy and the environment. The works to increase the use of solar energy and other sustainable tech- website has a significant amount of resources and research data. nologies across the nation. They accomplish this by public educa- tion and advocacy. The website is an up-to-date resource for infor- zzU.S. Department of Energy’s Solar America mation on the latest solar developments. Initiative www1.eere.energy.gov/solar/solar_america/index.html zzDatabase of State Incentives for Renewables and Efficiency (DSIRE) A program from the DOE, the Solar America Initiative strives to lower the cost of solar electricity so that it will be cost competitive www.dsireusa.org across the market by 2015. DSIRE is a comprehensive source of information on state, local, utility, and federal incentives that promote renewable energy and zzU.S. Department of Energy’s Solar Energies energy efficiency. Technology Program www1.eere.energy.gov/solar/ This site has some basic information about the different forms of existing solar technology, as well as newly emerging forms. About the NACo Green Government Initiative The NACo Green Government Initiative serves as a catalyst between local governments and the private sector to facilitate green government practices, products and policies that result in financial and environmental savings. Launched in 2007, the Initiative provides comprehensive re- sources for local governments on all things green, including energy, green building, air quality, transportation, water quality, land use, purchasing and recycling.

For more information contact Kelly Zonderwyk, NACo Senior Community Services Associate, at 202.942.4224 or [email protected].

25 Massachusetts Avenue, NW l Suite 500 l Washington, DC 20001 l 202.393.6226 l fax 202.393.2630 l www.naco.org