sign in sign up
<<
Home , Fossil fuel, Geothermal energy

Comparing the parameters of renewable, nuclear and generation technologies

Annette Evans Graduate School of the Environment, Faculty of Science, Macquarie University, NSW, Australia 2109 [email protected]

Assoc. Prof. Vladimir Strezov Graduate School of the Environment, Faculty of Science, Macquarie University, NSW, Australia 2109 [email protected]

Dr. Tim Evans Graduate School of the Environment, Faculty of Science, Macquarie University, NSW, Australia 2109 [email protected]

Abstract —The sustainability parameters of have been evaluated by the application of eight key indicators. Photovoltaics, wind, hydro, geothermal, crops, biomass residues, , and nuclear have been assessed according to their price, gas emissions, efficiency, use, use, availability, limitations and social impacts on a per kilowatt hour basis. The relevance of this information to the Australian context is discussed. Also included are the results of a survey on Australian opinions regarding electricity generation, which found that Australian prefer solar electricity above any other method and also support , with over 90% support, however coal, biomass and have low acceptance rates at 30% or less. Most Australians, greater than 90%, believe that the government is not doing enough to support renewable electricity.

Keywords -electricity; sustainability; cycle

I. INTRODUCTION

The generation of electricity worldwide is heavily dominated by the use of fossil . The of these fuels releases large amounts of dioxide and pollutants to the atmosphere. Fossil are also ultimately limited, with finite amounts in existence. While coal reserves are still abundant, the excessive consumption of coal by the electricity sector is responsible for the greatest share of emissions globally, as well as emitting large amounts of pollutants, such as NO x, SO 2, CO, particulate and air toxics to the environment.

World electricity production by fuel is shown in Figure 1 indicating coal and fuels contribute to over 40% of the world electricity generation, with fossil fuels in total accounting for over 65% of the electricity generated in 2006. sources are rapidly increasing in usage, however current market shares, excluding , are so low that it will be some time before a significant percentage of world electricity is produced by non-hydro renewable energy sources [1]. For example, in 2008 solar accounted for only 0.02% of the world’s electricity production [2], despite its 33% market growth between 1997 and 2005 [3]. Similarly, wind power has undergone an annual growth rate of nearly 50% between 1971 and 2004, yet only accounted for nearly 0.5% of the total world electricity production in 2004, with over 82 TWh generated globally [4].

Other, 2.3%

Hydro, 16%

Coal/Peat, 41%

Nuclear, 14.8%

Oil, 5.8%

Gas, 20.1%

Figure 1 World electricity production by fuel 2006 [1]

Increased electricity demand strengthens the need for reduced impacts from electricity generation per unit produced. Demand for electricity increased at an average of 1.8% per year between 1990 and 2004 [5]. IEA predictions show that, if the current coal dependence is not reduced, coal fired power stations in developing countries alone will produce more emissions than the entire OECD power sector in the year 2030 [6]. The impacts of developing nations working to achieve better standards of living, compounded by the number of people in these nations will cause electricity consumption rates to keep increasing.

In order to meet increasing energy requirements with minimal environmental impact, changes to the current energy generation practices are essential. Changes need to include increased energy efficiency from combustion technologies through introduction of oxyfiring and IGCC technologies, as well as increasing the share of alternative energy generation technologies, including hydropower, wind energy, geothermal, biomass combustion and , solar and . Renewable energy sources provide freedom from the price fluctuations, trade and issues associated with , gas and coal, and can potentially improve to countries deficient in resources. However, traditional coal and gas based technologies offer high reliability and low prices. Careful evaluation of the sustainability of each technology is needed to direct future investment and policy. This paper presents a sustainability assessment of electricity generation according to the sustainability indicators of price, , efficiency, , water use, availability, limitations and social impacts. Technologies are then compared and implications for electricity generation in Australia are discussed. Following this are the results of a survey of Australian public attitudes towards different methods of electricity generation.

A. The Sustainability Indicators

To assess the impacts of electricity generation, eight key sustainability indicators were selected that together highlight the financial, environmental, and social sustainability of each technology.

The cost is the first consideration in this study. Securing financial benefits is one of the key important figures that allow . Efficiency of is considered because it has a direct impact on cost and provides an indication of the maturity of the process with greater efficiencies achieved as the process is further developed. Greenhouse gas emissions, including carbon dioxide (CO 2) and (CH 4) determine the of the technology. is now becoming the single key emission parameter that determines sustainability. Emissions from criteria pollutants (SO 2, NOx, CO, Pb, PM 10 and O 3) are not considered here because there is a system in place controlling these emissions through policy and environmental compliance, which is already resulting in declining emissions of criteria pollutants, while the greenhouse gas emissions are showing an increasing global trend. Water use, as an indicator of sustainability, is particularly important in arid , such as Australia. Availability and limitations account for the ability of each technology to provide baseload electricity. Land use or the footprint is of most importance when technologies compete for space with housing, or culturally significant sites. Social impacts are the consideration of the direct and indirect affects on health and quality of life, often not covered adequately or at all in other categories.

B. Assessment Methods

An extensive literature review was performed to collect the data necessary to perform the sustainability assessment. All assessments are performed over the life cycle of each unit, on a per kilowatt hour basis where applicable.

A survey was conducted anonymously online, inviting members of the Australian community to share their opinions on different methods of electricity generation. Participants were asked about their preferred methods of electricity generation, nationally and locally, whether they support the idea of wind farms, solar farms, hydropower, biomass, coal and nuclear power stations and whether they think the government is doing enough to promote renewable technologies.

II. SUSTAINABILITY ASSESSMENT

A. Price

The average electricity price for all technologies is shown in USA dollars per kilowatt hour, averaged over the life cycle of the technology, as shown in Figure 2 [4][6-61]. Biomass dedicated energy crops are represented as Biomass DEC and biomass residues as Biomass RES.

10

1

0.1

Price $/kWh Price 0.01

0.001

l . l c o a C s a ind dr E a o ltai G C vo W Hy o s D ss Res s a Nuclear hot P Geotherm iom Bioma B

Figure 2 Prices of electricity generation

Nuclear, coal and gas are the cheapest methods of electricity generation costing on average 4.3, 4.8 and 4.8 c/kWh, respectively. Hydro, biomass residues, wind, geothermal and biomass energy crops are slightly more expensive, at 5.1, 5.4, 6.6, 6.8 and 8 c/kWh on average. The average cost of photovoltaics is quite prohibitive under normal circumstances, at 24c/kWh. It is nearly 6 times more expensive than the average nuclear price.

There is significant variability within the results, particularly for the renewable energy sources. has the largest data range and also the lowest possible cost at only 0.7c/kWh [29] and all renewable energy sources, even photovoltaics have the potential to be cheaper than coal and gas. Electricity produced from hydro, geothermal, biomass residues and wind can also be cheaper than nuclear at their lowest prices, while the lowest costs for photovoltaics and biomass energy crops are slightly higher than for nuclear. This highlights the importance of careful site selection and planning. Electricity produced from coal and gas show more stable price ranges, compared to renewable energy sources. This is primarily due to the maturity of these technologies and the consistency of fuel products across the world.

B. Efficiency

The efficiency of conversion from the energy in the fuel source into electricity is an important parameter which needs to be considered when assessing electricity production technologies. Efficiencies strongly influence prices as well as sustainability, since the high levels of waste associated with an inefficient process are unsustainable. However, there are diminishing returns in efficiency improvements. Inefficient processes operating at 10% efficiency will significantly improve profits if a 1% improvement is made, whereas in an efficient process, already achieving 50% efficiency, a 5% improvement is necessary to achieve such gains. A summary of efficiencies for each power generation technology, as found in literature, is shown in Table 1 [7][30][32][41][52][55][62-92].

Table 1 Electrical efficiencies of electricity generation

Technology Efficiency Range Photovoltaic 4 - 22% Wind 23 - 45% Hydro >90% Geothermal 10 - 20% Biomass 16 - 43% Gas 45 - 53% Coal 32 - 45% Nuclear 30 - 36%

Hydropower has the highest efficiency, from double to 5 times above the highest achieved in all other technologies. When located at a high quality wind , wind power is the second most efficient renewable , followed closely by high efficiency biomass. Natural gas shows the second highest overall efficiency and is the most efficient thermal technology. However, it must be considered that gas, coal and nuclear, have small ranges of efficiency, varying by up to 13%. This is unlike wind, which if not placed correctly can halve its potential and varies by up to 22%. Biomass has an even larger data range, varying by up to 27%. At its highest efficiency, biomass is comparable with coal and higher than nuclear. At its lowest efficiency the electricity produced from biomass is one of the least efficient choices. Lowest quoted efficiencies are often for older technologies and methods. The large efficiency range for photovoltaics is due to differing cell types, with amorphous silica cells showing the lowest efficiencies and crystalline silica cells the highest. Geothermal efficiencies vary due to the of the geothermal source; hotter geothermal sources give greater efficiencies. C. Greenhouse Gas Emissions

World electricity production resulted in the release of over 10 billion of carbon dioxide equivalent to atmosphere, or 40% of the total CO 2 emissions for 2004 [4]. This is an increase of 53% since 1990. Renewable energy technologies are often seen as methods for reducing global greenhouse gas emissions, however each renewable energy technology is not entirely greenhouse gas neutral. For instance, although wind turbines and photovoltaic cells do not emit CO 2 during operation, there are CO 2 emissions associated with construction, installation and disposal/recycling of each system. Hydro dams have greenhouse gas emissions during construction, but also during operation as a result of the decay of organic material within the dam. Most of this occurs in anoxic zones within the dam, resulting in anaerobic, methane forming decay.

The results for greenhouse gas emissions for each technology are shown in Figure 3 [19][22][26][30][32][35][46][56][60][62][64-65][69-70][72-73][77][81][85][87][93-129], as carbon dioxide equivalent, or ‘CO 2e’. Nuclear has the lowest average and range of emissions, averaging 16 gCO 2e/kWh and as low as 1.8 gCO 2e/kWh. Enrichment of the ore has the most significant impact on nuclear emissions, therefore the higher values for nuclear are associated with uranium enrichment by diffusion, which is at least 30 times more energy intensive than enrichment by centrifugation [81].

10000

1000

e/kWh 100 2 CO 10

1 l d a s. s al taic n dro e a o y rm R G C clear ol Wi H e u v th to o N o e Ph G Biomass Biomass DEC Figure 3 Greenhouse gas emissions from electricity generation

Wind, biomass residues and hydro also have very low emissions, with averages of 25, 30 and 41 gCO 2e/kWh, and lows of 4, 5.3 and 2 gCO 2e/kWh, respectively. Most emissions from wind power are the result of turbine manufacture. Biomass residue emissions are from the collection and transportation of a low energy density fuel. For hydro, it is dam construction that contributes most significantly to emissions of greenhouse gases. Dam emissions are also affected by site specific variables, such as temperature, rainfall, residence time, flooded terrain shape, etc. The greatest indication of emissions seems to be the power density of the , or the capacity of the plant divided by the flooded area of the dam. with higher power densities showed the lowest emissions [130].

Photovoltaics, biomass energy crops and geothermal have low to moderate average emissions, with all minimum values less than 25 gCO 2e/kWh. The maximum value for geothermal is significant, 740 gCO 2e/kWh however such values are rare as indicated by the much lower average emissions.

Gas and coal have the highest emissions, at averages of 543 and 1004 gCO 2e/kWh, respectively.

Greenhouse gas emissions for the production of wind turbines and solar cells vary according to the country of production, primarily due to the differences in the electricity grid mix of the specific country. Countries which are dependent on fossil fuels for electricity production have larger greenhouse gas emissions associated with the production of wind turbines and photovoltaic cells. Therefore, a typical electricity grid mix for the country of production should be defined for the emissions in question. For instance, greenhouse gas emissions for a typical American electricity grid are over 30% higher than European emissions. Australian photovoltaic emissions are also high as a result of almost exclusive fossil-fuel based electricity generation. There have been few studies which analyse the use of only renewable produced electricity to operate a factory producing wind turbines or photovoltaic cells. Pacca et al. [115] found that using photovoltaic power to supply electricity for production of photovoltaic modules reduced the total CO 2 emissions of a thin film module by 82% to only 6.1 g CO 2/kWh. Hence, one of the potential strategies for the reduction of greenhouse gas emissions during production of solar cells is promoting solar cell production in countries or regions that utilise renewable, low emission energy sources for electricity.

D. Water Use

In an arid such as Australia, water is a vital resource that must be carefully conserved at every opportunity. Many electricity generating methods require large quantities of water for cooling. Literature values for water consumption and total withdrawal during electricity generation are shown in Table 2 [131-134]. Consumption is water that is evaporated, or lost from the system that cannot be returned to the source. Withdrawal is the total amount required to operate the technology and includes water available for recycling. At only 1g of water used per kilowatt hour, wind has negligible water use. Photovoltaics also use very little water with only 10 g/kWh. Due to these extremely low values, wind and photovoltaics are highly sustainable with respect to water consumption . Table 2 Water consumption and withdrawal during electricity generation

Larson et al. Trewin Younos et al. Inhaber Consumption kg water/kWh Withdrawal Photovoltaics negligible 0.01 Wind 0.001 Hydropower 11 3,740* 0.26 20 13,600 Geothermal 0.3 - 1.6 1.7 12 - 300 Biomass Waste 3.2 Biomass Energy Crops 34 Gas 0.3 - 0.5 0.6 1.6 78 Coal 0.3 - 0.5 1.5 14 - 28 1.6 78 Nuclear 31 - 75 1.8 107 *Denotes withdrawal

The results by Inhaber [131] for geothermal differ markedly to the findings of Younos et al. [134], who give a consumption of 1.7 kg/kWh. Water consumption for geothermal varies widely, depending on water capture and recycling efficiency as well as the temperature of the geothermal resource. It is possible to have a closed system with generation that achieves the lower limits shown. Gas and coal show the same water withdrawal, 78 kg water/kWh as both use water in the same way for cooling. Inhaber [131] states that water consumption for these technologies is 1.6 kg/kWh, which is consistent with the Australian Bureau of Statistics findings of Trewin [133] for coal fired power stations at 1.5 kg/kWh, but much less than the findings of Younos et al. [131] at 14 – 28 kg/kWh. Trewin [133] gives a lower average for gas at 0.6 kg/kWh. Biomass water consumption is higher than coal and gas, since biomass combustion consumes similar amount of water but there is also the added water load of crop growth (if applicable), collection and transportation of a low energy dense fuel and drying of a high moisture fuel. Dedicated energy crops have a water requirement over ten times higher than waste biomass. Nuclear power has a high requirement for cooling water in the reactors. Inhaber [131] states a water consumption of 1.8 kg/kWh for electricity production from biomass, which is again much lower than the findings of Younos et al. [134] at 31 – 75 kg/kWh.

As expected, hydropower has the largest water withdrawal, as it requires significant water storage volumes. Storage in this way results in water losses by evaporation from the dam, the magnitude of which is influenced by the total dam surface area and , local and geography. Inhaber found the average water loss from hydropower dams to be around 19 kg/kWh. Younos et al. [134] found a much lower water loss of 0.26 kg/kWh, which would make hydropower among the most sustainable water users. Trewin [133] gives the highest average water withdrawal at 3740 kg/kWh across Australian hydropower sites, however it is also stated that nearly all of this water is used in- stream and not consumed.

E. Availability

Fossil fuels and nuclear power have finite reserves available that limit how long the technology can be applied. Current estimates by Shafiee and Topal [135] for the time remaining until resources are depleted are 107 years for coal and 35 years for gas. The World Nuclear Association [136] estimated 70 years of uranium reserves, based on current consumption rate of 66.5 kt uranium/year and known resources of 4.7 Mt uranium.

High grade geothermal resources are available in over 80 countries around the world, with a potential generating capacity of 11±1.3 PWh/year [137]. The feasible, currently economical potential is estimated at 8.1 PWh/year, with a total theoretical potential of around 400 PWh/year [138]. This is much larger than the current production level of 2.6 PWh/year. For comparison, it should be noted that global in 2009 was 20.2 PWh [2]

Due to the inconsistent nature of wind speeds, there are limitations on potential of wind power at a single site. No power is generated at wind speeds below 3-5 m/s and turbines must be stopped at high wind speeds above 20-25 m/s to avoid damage [60]. Therefore, wind power can only be produced when the wind speed is between this range. To overcome this problem a range of favourable sites should be used, which, between them, should smooth variation and supply a consistent amount of electricity. The IEA [139] estimated a global wind potential of 40 PWh/year.

Energy from the sun is a virtually unlimited resource. The intercepts a solar flux of over 170 PW of every year [140]. In 2007, the world consumption of electricity was 5.5 TW [141]. Solar intensity on Earth varies by season, latitude, weather and time of day. Averaged on an annual daily basis, a good solar climate, such as Australia, receives about 5–6 kWh/m 2/day with summer to winter levels varying by a factor or 2 to 1. A poor solar climate, such as Northern Europe, will receive around 2–3 kWh/m 2/day and has a greater seasonal variation [10]. The optimal climate for solar collection is a desert, where in excess of 300 sunny days per year can be expected [10].

It has been estimated that the global potential for electricity production from biomass is as high as 200 EJ/year [142]. Kaygusuz [143] gave an estimated potential of 270 EJ on a basis of sustainability, significantly higher than the sustainable potential of 100 EJ/year given by Parikka [144]. It must be noted that even the lowest of these values, 100 EJ/year, still represents 30% of the global total energy consumption for 2004. The CEC [145] calculated the long term potential of bagasse at 7.8 TW/year.

Biomass shows the highest availability. All technologies show the potential to make a significant contribution to the world’s electricity generation supply. Hydropower is the only technology with current generation measureable in the same units as its potential, with 40% of its economically feasible potential, or 3.2 PWh produced in 2009 [2]

F. Limitations

The limitations of different technologies are difficult to quantitatively compare. The intermittent nature of wind and photovoltaics is a very different limitation to the limitations on the amount of biomass or water available for power production. Without storage capabilities, wind and solar can only feed into the grid when the wind is blowing or sun is shining, which makes them incapable of providing baseload power. It also causes complications with regard to load forecasting when these technologies provide a high percentage of the grid, they cannot always be relied upon to deliver the amount of electricity predicted. Recent research suggests possible applications for wind power [146].

For biomass and hydropower operation where reserves are in limited supply, fuel can be collected until there are sufficient amounts available to operate without interruption. Such management can help smooth the load during peak operation, or provide electricity during peaking times when it is needed most. Where fuel is abundant both hydropower and biomass can operate at steady state baseload. This flexibility is a significant advantage. Hydropower also has the highest reliability of any generating source [147], providing there is sufficient water in the dam.

Geothermal has the least limitations of the studied renewable energy sources, provided that the area of consideration is geothermally appropriate. Once installed and operational, geothermal power plants operate 24 hours a day, providing baseload due to the reliability of the power, with plant life times around 20 years [138].

G. Land Use

Land occupation is a measure of the direct and indirect footprint area required. It is a measure of how much land is required for a technology to operate. It does not convey the way in which the land is used, for how long it is used or how much damage is done to the site as a result of the technology. Table 3 shows land occupation values taken from Fthenakis and Kim [101] and Bertani [148].

Table 3 Life cycle land occupation for electricity generation

Technology Gagnon m 2/kWh Fthenakis m 2/kWh Photovoltaic 0.045 0.0003 Wind 0.072 0.0015 Hydro 0.152 0.004 Geothermal (Bertani 2005) 0.05 0.05 Biomass Energy Crops 0.533 0.0125 Biomass Residues 0.001 Gas 0.0003 Coal 0.004 0.0004 Nuclear 0.0005 0.00005 According to the results in Table 3, nuclear has the lowest land requirement of the technologies studied. Coal and gas also have low land requirements, making these 3 technologies the most sustainable with regard to land use, ignoring the damaging impact on the land used over the life cycle. Photovoltaic land use is also sustainable, however, this is the total land use for ground mounted photovoltaic modules; building integration and rooftop mounting would significantly reduce this footprint. Wind power land use is high, but this is the value for the entire . Actual turbine occupation is typically only 1- 10% of this area, with the remaining site used for grazing, agriculture or recreation [101]. Hydropower land occupation is the second highest due to large dam requirements. Biomass results are extremely high, over four times higher than the closest result for hydropower.

H. Social Impacts

The manufacture of solar cells involves the use of several toxic, carcinogenic, flammable and explosive chemicals. With constantly reducing requirements during cell manufacture due to thinner cells, involved and hence risks are reduced however, all chemicals must be carefully handled to ensure minimal human and environmental contact. There are also toxic substances used during operation, including antifreeze, rust inhibitors and heavy metals that leach from the system [149]. Glare from solar panels is a hazard to eyesight, therefore care must be taken where this is an issue.

Solar farm locations must be carefully selected to reduce competition with agriculture, erosion and compaction, wind diversion, potential reductions in evaporation rates from soil and disruption of ground and flow [149].

The main impacts of wind power are typically noise, visual intrusion and bird strike. When operational, wind farms generate some noise from the rotation of the blades and machinery noise from the gearbox and generator. Public annoyance at the visual impact can be significant. Wolsink [150] found it to be the most influential factor in public opposition to wind farms. Noise annoyance was more affected by visual impact attitudes than by the actual resulting from the turbines [151].

Several early wind farms were found to have a negative impact on birdlife due to bird contact with wind turbines. In depth studies of the proposed area prior to construction ensure any bird flight patterns can be accounted for in the design, to reduce the probability of bird strike. Bird kill by well designed, modern wind farms is now rare [60].

Hydropower dams provide a means of control and as well as an area for recreational water pursuits and conservation areas surrounding the dam. They may also form a tourist attraction. The worst effect of dam installation is the displacement of communities within the flood area. These people are often the poorest communities, living and farming the area for generations. Many studies have shown the serious implications and trouble these people have adjusting after removal (e.g. [32][152]). Dam inundation will usually also result in the loss of archaeologically and culturally significant sites as well as disrupting fish migration patterns.

There are potential health risks to the community if dam contaminant levels are not carefully monitored. Mailman [153] showed that people consuming fish out of hydro reservoirs have an increased risk for accumulation of methyl . Waterborne diseases also require attention, particularly in tropical areas [32].

The likely adverse environmental impacts associated with geothermal power generation include surface disturbances, physical effects, such as land caused by fluid withdrawal, noise, thermal pollution and the release of offensive chemicals [149]. There are large variations from site to site that are also technology dependent. Many geothermal systems have emission and waste free operation [41]. The single location required for power production, avoids the need for mines, pipelines and waste repositories. The reinjection of process water increases in the frequency, but not severity of seismic activity [154]. This is less of a problem than the soil and waterway contamination and increased water use if waste is not reinjected, since geothermal fluid contains significant amounts of sulphide, , mercury, radon, [155] cadmium, lead and [156]. Abbasi & Abbasi [149] found highly mineralised water carried from cooling towers and killing downwind vegetation in .

Food competition is the key social issue with biomass. In many cases, energy crops compete with crops for valuable agricultural land. To avoid this competition, energy crops need to be grown only on agricultural land not used for food crops. In poor communities, biomass removal may also remove fuel for heating and cooking. Along with agricultural land, are an essential site for biomass crop growth. The removal of wood waste from forests is partially compensated by returning wood ash, rich in mineral nutrients and counteracting acidification, however nitrogen and organic matter are lost, the effects of stump harvesting and loss of are not balanced [157]. The loss of habitat and biodiversity are key influences on the lack of public acceptance and support for the use of native residues, which are the main available biomass resource [158].

Direct labour inputs for wood biomass are two to three times greater per unit energy than for coal [149]. There is also an increased labour requirement for construction, operation and maintenance. More occupational injuries and illnesses are associated with biomass in agriculture and than with underground coal , oil or gas extraction. Agriculture has 25% more injuries per man day than all other private industries [149].

The social impacts of coal, gas and nuclear technologies are more widely understood. Mining for mineral resources often occurs in delicate environments and alongside communities. Land occupation by mining is highly invasive, removing large areas of vegetation and animal habitat and requiring significant rehabilitation after use has ended. It may also irrevocably damage archaeologically and culturally significant sites. Exhaust gases from thermal fuels are highly contaminated with pollutants, such as sulphur, nitrous oxide, dioxins, and heavy metals, which are then dispersed over wide areas. Coal is particularly high in mercury.

Nuclear power impacts the community through the mining, milling, transportation, fabrication, enrichment and disposal of uranium, plant operation and decommissioning, uncontrolled leaks, mine wastes and mill tailings, the health effects of low level radiation exposure on workers, the carcinogenic effects of exposure and proliferation [159]. Many researchers have found clusters of higher than background childhood leukaemia incidence in areas surrounding nuclear power plants [160-163].

III. SOCIAL ACCEPTANCE OF ENERGY TECHNOLOGIES IN AUSTRALIA

A survey was conducted to assess social acceptance of energy technologies in Australia. A total of 282 responses were received in the survey. The results overwhelmingly showed community support favouring , with over 56% believing solar power is the best choice for Australia, as shown in Figure 4 and over 49% for their local area, as shown in Figure 5. Over 96% of respondents would consider or have already installed solar power in their home and over 95% support the idea of solar farms. These results are consistent with the Australian climate and highlight the significance of local conditions on public opinion. After solar, wind was viewed most favourably, particularly from a local perspective, supported by 13% of respondents. The need for variety within the electricity grid mix was acknowledged by at least 10% of respondents (typically those that selected ‘other’) with comments regarding the necessity of several solutions, that there is no single right answer. Gas, 3.2% No Response, Coal, 4.3% 3.2% Geothermal, 3.2% Other, 9.9% Hydropower, 3.5% Wind, 8.2% Nuclear, 5.7%

Wave, 2.1%

Solar, 56.4%

Figure 4 Preferred national electricity choice

Biomass, 1.8% No Response, Coal, 6.0% 5.7% Gas, 6.7%

Other, 4.6% Geothermal, 0.7%

Wind, 13.1% Hydropower, 4.3%

Nuclear, 3.9% Wave, 3.5%

Solar, 49.6%

Figure 5 Preferred local electricity choice

The level of support for all non-solar technologies was significantly lower, with the exception of wind power, as shown in Table 4. Wind was the only non-solar technology to receive over 90% of public favour. Hydropower had strong support, but also strong and vocal opposition, with many concerned about the damaging effects to and aquatic as a result of dam inundation and downstream water losses. Biomass power generation is not typically seen as renewable, receiving a similar response to coal fired power stations. Nuclear power was the least favoured option, with almost 75% of respondents not supporting the installation of nuclear power in the currently nuclear free Australian grid.

Table 4 Public support for different methods of electricity generation

Solar Farms Wind Farms Hydro Biomass Coal Nuclear Support 95.7% 91.1% 70.6% 31.2% 30.1% 23.8% Against 1.8% 6.4% 27.0% 66.0% 67.4% 74.8% No Response 2.5% 2.5% 2.5% 2.8% 2.5% 1.4% One of the strongest responses to the survey was that over 90% of respondents do not believe the government is doing enough to support renewable energy technologies.

IV. CONCLUSION

The sustainability of electricity generation from photovoltaics, wind, hydro, geothermal, biomass, coal, natural gas and nuclear fuels has been assessed according to eight key sustainability indicators.

On the basis of price of electricity, coal and nuclear had the best average prices, while hydro and geothermal showed the lowest possible prices. Photovoltaics had both the highest average and overall highest cost, but at the lowest limits it was cheaper than coal or gas and only slightly more expensive than nuclear power. Hydropower shows the highest and photovoltaics the lowest electrical efficiency. Greenhouse gas emissions were low in all non-fossil fuels, with wind, hydro and nuclear showing the lowest values. Coal had the highest emissions by a significant margin.

Water use was the lowest in photovoltaics and wind power and highest for dedicated biomass energy crops. Hydro power has a very high water requirement, however most of this is returned to the stream. Hydropower has the highest availability. Photovoltaics show the lowest availability, however they also showed one of the lowest levels of limitations, due to the global abundance and distribution of sunlight. Coal is also favourably low in limitations due to abundant and wide spread reserves. Biomass shows the highest limitations.

Nuclear, photovoltaics and wind power have the smallest land use, with biomass the largest. With respect to social impacts, wind and photovoltaics are the most sustainable, while all thermal technologies had low sustainability in this area.

Applying this information to NSW, Australia, which is a hot, sunny and dry climate with a moderate population, the best technology choice would be wind power, due to low costs, good availability, low water consumption and low social impacts. Although there is also a significant level of public support for wind power within the Australian community, the solar technology appears to be the most favourable among the majority of the anonymous survey respondents conducted for this study in Australia. V. REFERENCES [1] International Energy Agency. (2008) "Key World Energy Statistics 2008." [2] Euromonitor International (2010). Global information database, Euromonitor International. [3] Hoffmann, W. (2006). "PV solar electricity : Market growth and perspective." Materials and Solar Cells 90(18-19): 3285-3311. [4] International Energy Agency. (2007). Renewables in global . [5] International Energy Agency, IEA, (2007). Findings of recent IEA , IEA. [6] International Energy Agency. (2004) "World Energy Outlook 2004." [7] Ansolabehere, S., Deutch, J. et al. (2003). The Future Of Nuclear Power, Institute of Technology. [8] Awerbuch, S. (2000). "Investing in photovoltaics: risk, accounting and the value of new technology." 28(14): 1023-1035. [9] Cavallo, A. (2007). "Controllable and affordable utility-scale electricity from intermittent wind resources and compressed air (CAES)." Energy 32(2): 120-127. [10] Charters, W. W. S. (1991). "Solar energy: Current status and future prospects." Energy Policy 19(8): 738-741. [11] Cottrell, A., Nunn, J. et al. (2003). Systems Assessment of Future Electricity Generation Options for Australia. Technology Assessment Report 32. CCSD. [12] DeCarolis, J. and Keith, D. (2002). Is the answer to blowing in the wind? Proceedings of the first International Doctoral Consortium on Technology, Policy, and Management, Delft, The Netherlands. [13] DENA (2005) "German Energy Agency Dena study demonstrates that large scale integration of wind energy in the electricity system is technically and economically feasible." [14] Denholm, P. (2006). "Improving the technical, environmental and social performance of wind energy systems using biomass-based energy storage." Renewable Energy 31(9): 1355-1370. [15] Deutch, J. M. and Lester, R. K.. Making technology work. Applications in energy and the environment., Cambridge University Press, 2004. [16] Dincer, I. (1999). "Environmental impacts of energy." Energy Policy 27: 845-854. [17] Dincer, I. (2000). "Renewable energy and sustainable development: a crucial review." Renewable & Reviews 4(2): 157-175. [18] Drennen, T. E., Erickson, J. D. et al. (1996). "Solar power and climate change policy in developing countries." Energy Policy 24(1): 9-16. [19] Dudhani, S., Sinha, A. K. et al. (2006). "Renewable energy sources for peak load demand management in India." International Journal of Electrical Power & Energy Systems 28(6): 396-400. [20] Edmonds, J., Wise, M. et al. (2007). Global Energy Technology Strategy- Addressing Climate Change. G. E. T. S. Program, Battelle Memorial Institute. [21] El-Fadel, M., Chedid, R. et al. (2003). "Mitigating energy-related GHG emissions through renewable energy." Renewable Energy 28(8): 1257-1276. [22] El-Kordy, M. N., Badr, M. A. et al. (2002). "Economical evaluation of electricity generation considering ." Renewable Energy 25(2): 317-328. [23] Evrendilek, F. and Ertekin, C. (2003). "Assessing the potential of renewable energy sources in ." Renewable Energy 28(15): 2303-2315. [24] Fridleifsson, I. B. and Freeston D. H. (1994). "Geothermal-Energy Research-and-Development." Geothermics 23(2): 175-214. [25] Gross, R. (2004). "Technologies and for system change in the UK: status, prospects and system requirements of some leading renewable energy options." Energy Policy 32(17): 1905-1919. [26] Hammons, T. J. (2004). "Geothermal power generation worldwide: Global perspective, technology, field experience, and research and development." Components and Systems 32(5): 529-553. [27] Herbert, G. M. J., Iniyan, S. et al. (2007). "A review of wind energy technologies." Renewable & Sustainable Energy Reviews 11(6): 1117-1145. [28] Houri, A. (2006). "Prospects and challenges of using hydropower for electricity generation in Lebanon." Renewable Energy 31(11): 1686-1697. [29] Idaho National Laboratory. (2005) "Hydropower Plant Costs and Production Expenses." [30] International Energy Agency. (2006). Annual Report 2005. [31] IEEJ (2006). Solar Photovoltaic Market, Cost and Trends in the EU. [32] Ito, M., Kato, K. et al. (2003). "A preliminary study on potential for very large-scale photovoltaic power generation (VLS-PV) system in the Gobi desert from economic and environmental viewpoints." Solar Energy Materials and Solar Cells 75(3-4): 507-517. [33] Jager-Waldau, A. and Ossenbrink, H. (2004). "Progress of electricity from biomass, wind and photovoltaics in the European Union." Renewable & Sustainable Energy Reviews 8(2): 157-182. [34] Kammen, D. M. and Pacca, S. (2004). "Assessing the costs of electricity." Annual Review of Environment and Resources 29: 301-344. [35] Kannan, R., Leong, K. C. et al. (2007). "Life cycle energy, emissions and cost inventory of power generation technologies in Singapore." Renewable & Sustainable Energy Reviews 11(4): 702-715. [36] Koch, F. H. (2002). "Hydropower--the politics of water and energy: Introduction and overview." Energy Policy 30(14): 1207-1213. [37] Lackner, K. S. and Sachs, J. D. (2005). "A robust strategy for sustainable energy." Brookings Papers on Economic Activity(2): 215-284. [38] Lovseth, J. (1995). "The Renewable Energy Potential of Norway and Strategies for Its Development." Renewable Energy 6(3): 207-214. [39] MacLeod, M., Moran, D. et al. (2006). "Counting the cost of water use in hydroelectric generation in ." Energy Policy 34(15): 2048-2059. [40] McGowan, J. G. and Connors, S. R. (2000). "WINDPOWER: A Turn of the Century Review." Annual Review of Energy & the Environment 25(1): 147. [41] Mock, J. E., Tester, J. W. et al. (1997). "Geothermal energy from the earth: Its potential impact as an environmentally sustainable resource." Annual Review of Energy and the Environment 22: 305-356. [42] Moran, D. and Sherrington, C. (2007). "An economic assessment of windfarm power generation in Scotland including externalities." Energy Policy 35(5): 2811-2825. [43] Muneer, T., Asif, M. et al. (2005). "Sustainable production of solar electricity with particular reference to the Indian economy." Renewable & Sustainable Energy Reviews 9(5): 444-473. [44] Nuclear Energy Institute, N. E. I. (2006). U.S. Electricity Production Costs [45] Organisation For Economic Co-Operation And Development, and the Nuclear Energy Agency (2003). Nuclear Electricity Generation: What Are the External Costs? [46] Pacca, S. and Horvath, A. (2002). "Greenhouse gas emissions from building and operating electric power plants in the upper Colorado River Basin." Environmental Science & Technology 36(14): 3194-3200. [47] Peltier, R. (2004). "Nuclear renaissance continues." Power 148(5): 32-+. [48] Roques, F. A., Nuttall, W. J. et al. (2006). "Nuclear power: A hedge against uncertain gas and carbon prices?" Energy Journal 27(4): 1-23. [49] Sanner, B. and Bussmann, W. (2003). "Current status, prospects and economic framework of geothermal power production in Germany." Geothermics 32(4-6): 429-438. [50] Schumacher, K. and Sands, R. D. (2006). "Innovative energy technologies and climate policy in Germany." Energy Policy 34(18): 3929-3941. [51] Sims, R. E. H. (1994). "Electricity-Generation from Woody Biomass Fuels Compared with Other Renewable Energy Options." Renewable Energy 5(5-8): 852-856. [52] Sims, R. E. H., Rogner, H. H. et al. (2003). "Carbon emission and mitigation cost comparisons between fossil fuel, nuclear and renewable energy resources for electricity generation." Energy Policy 31(13): 1315-1326. [53] Soderholm, P., Ek, K. et al. (2007). "Wind power development in Sweden: Global policies and local obstacles." Renewable & Sustainable Energy Reviews 11(3): 365-400. [54] Tarjanne, R. and Rissanen S. (2000). Nuclear Power: Least-Cost Option for Baseload Electricity in Finland. The Uranium Institute 25th Annual Symposium, London. [55] Australian Uranium Association and Uranium Information Centre. (2007) "Australia's Electricity." [56] United Nations Development Program, U. N. D. P. (2000). World Energy Assessment Energy and the Challenge of Sustainability. [57] United Nations Development Program, U. N. D. P. (2004). World Energy Assessment Overview 2004 Update. J. Goldemberg and T. B. Johansson. [58] University of Chicago. (2004). The Economic Future Of Nuclear Power. [59] der Zwaan, B. and Rabl, A. (2003). "Prospects for PV: a learning curve analysis." Solar Energy 74(1): 19- 31. [60] World Energy Council. (2007). 2007 Survey of Energy Resources. W. E. Council. [61] Wibberley, L., Cottrell, A. et al. (2006). Techno-economic Assessment of Power Generation Options for Australia. Technology Assessment Report 52. [62] A. E. A. Technology, (2005). Environmental Product Declaration of Electricity from Torness Nuclear . [63] Andersson, B. A. and Jacobsson, S. (2000). "Monitoring and assessing technology choice: the case of solar cells." Energy Policy 28(14): 1037-1049. [64] Barbier, E. (2002). "Geothermal energy technology and current status: an overview." Renewable & Sustainable Energy Reviews 6(1-2): 3-65. [65] Bilek, M., Lenzen, M. et al. (2006). Life-Cycle Energy and Greenhouse Gas Emissions of Nuclear Power in Australia, The University of Sydney: 181. [66] Chopra, K. L., Paulson, P. D., et al. (2004). "Thin-film solar cells: an overview." Progress in Photovoltaics: Research and Applications 12(2-3): 69-92. [67] de Wild - Scholten, M. J. and Alsema, E. A. (2006). Environmental Life Cycle Inventory of Crystalline Silicon Photovoltaic Module Production - Excel file Proceedings of the Materials Research Society Fall 2005 Meeting, Symposium G, Boston, USA, ECN Solar Energy [68] DiPippo, R. (2007). "Ideal for geothermal binary plants." Geothermics 36(3): 276-285. [69] Dones, R. and Frischknecht, R. (1998). "Life-cycle assessment of photovoltaic systems: Results of Swiss studies on energy chains." Progress in Photovoltaics 6(2): 117-125. [70] Dones, R., Heck, T. et al. (2005). ExternE-Pol Externalities of Energy: Extension of Accounting Framework and Policy Applications. [71] Energy Information Agency, E. I. A. (2007). International Energy Outlook 2007, Energy Information Administration. [72] Frankl, P., Masini, A.et al. (1998). "Simplified Life-cycle Analysis of PV Systems in Buildings: Present Situation and Future Trends." Progress in Photovoltaics: Research Applications 6(2): 137-146. [73] Fthenakis, V. and Alsema, E. (2006). "Photovoltaics energy payback times, greenhouse gas emissions and external costs: 2004-early 2005 status." Progress in Photovoltaics: Research and Applications 14(3): 275-280. [74] Fthenakis, V. M. and Moskowitz, P. D. (2000). "Photovoltaics: environmental, health and safety issues and perspectives." Progress in Photovoltaics: Research and Applications 8(1): 27-38. [75] Green, M. A. (2000). "Photovoltaics: technology overview." Energy Policy 28(14): 989-998. [76] Green, M. A., Emery, K.et al. (2007). "Solar cell efficiency tables (version 29)." Progress in Photovoltaics 15(1): 35-40. [77] Greijer, H., Karlson, L. et al. (2001). "Environmental aspects of electricity generation from a nanocrystalline dye sensitized solar cell system." Renewable Energy 23(1): 27-39. [78] Gurzenich, D. and Wagner, H. J. (2004). "Cumulative energy demand and cumulative emissions of photovoltaics production in Europe." Energy 29(12-15): 2297-2303. [79] Hegedus, S. (2006). "Thin film solar modules: the low cost, high throughput and versatile alternate to Si wafers." Progresss in Photovoltaics: Research and Applications 14: 393-411. [80] Hepbasli, A. (2003). "Current status of geothermal energy applications in Turkey." Energy Sources 25(7): 667-677. [81] Hondo, H. (2005). "Life cycle GHG emission analysis of power generation systems: Japanese case." Energy 30(11-12): 2042-2056. [82] Jungbluth, N., Bauer, C. et al. (2005). "Life cycle assessment for emerging technologies: Case studies for photovoltaic and wind power." International Journal of Life Cycle Assessment 10(1): 24-34. [83] Kanoglu, M. (2002). " analysis of a dual-level binary geothermal power plant." Geothermics 31(6): 709-724. [84] Mason, J. E., Fthenakis, V. M. et al. (2006). "Energy payback and life-cycle CO2 emissions of the BOS in an optimized 3•5 MW PV installation." Progress in Photovoltaics: Research and Applications 14(2): 179-190. [85] Meijer, A., Huijbregts, M. A. J. et al. (2003). "Life-cycle assessment of photovoltaic modules: Comparison of mc-Si, InGaP and InGaP/mc-Si solar modules." Progress in Photovoltaics: Research and Applications 11(4): 275-287. [86] Mohr, N. J., Schermer, J. J. et al. (2007). "Life cycle assessment of thin-film GaAs and GaInP/GaAs solar modules." Progress in Photovoltaics: Research and Applications 15(2): 163-179. [87] Oliver, M. and Jackson, T. (2000). "The evolution of economic and environmental cost for crystalline silicon photovoltaics." Energy Policy 28(14): 1011-1021. [88] Treble, F. (1998). "Milestones in the development of crystalline silicon solar cells." Renewable Energy 15(1- 4): 473-478. [89] Tripanagnostopoulos, Y., Souliotis. M., et al. (2005). "Energy, cost and LCA results of PV and hybrid PV/T solar systems." Progress in Photovoltaics: Research and Applications 13(3): 235-250. [90] University of Wollongong. (2007). "Nuclear Power & Australia?", from http://www.uow.edu.au/eng/phys/nukeweb/reactors_types.html. date accessed 20/10/2009 [91] , M. E., Johnson, A. J. et al. (1998). "Life-cycle air emissions from PV power systems." Progress in Photovoltaics 6(2): 127-136. [92] Yang, H., Wang, H. et al. (2003). "Status of photovoltaic industry in China." Energy Policy 31(8): 703-707. [93] Alsema, E. A. and Nieuwlaar, E. (2000). "Energy viability of photovoltaic systems." Energy Policy 28(14): 999-1010. [94] Armannsson, H., Fridriksson, T. et al. (2005). "CO 2 emissions from geothermal power plants and natural geothermal activity in ." Geothermics 34(3): 286-296. [95] Bertani, R. and Thain, I. (2002). "Geothermal power generating plant CO 2 emission survey." IGA News 49: 1-3. [96] Brown, M. T. and Ulgiati, S. (2002). " evaluations and environmental loading of electricity production systems." Journal of Cleaner Production 10(4): 321-334. [97] Chatzimouratidis, A. I. and Pilavachi, P. A. (2007). "Objective and subjective evaluation of power plants and their non-radioactive emissions using the analytic hierarchy process." Energy Policy 35(8): 4027-4038. [98] Denholm, P., Kulcinski, G. L. et al. (2005). "Emissions and Energy Efficiency Assessment of Baseload Wind Energy Systems." Environ. Sci. Technol. 39(6): 1903-1911. [99] Dones, R., Hirschberg, S. et al. (1994). Greenhouse gas emission inventory based on full energy chain analysis. Comparison of energy sources in terms of their full-energy-chain emission factors of greenhouse gases, IAEA Advisory Group meeting/Workshop. [100] Elsam Engineering, A. S. (2004). Life cycle assessment of onshore and offshore sites wind power plants. [101] Fthenakis, V. M. and Kim, H. C. (2007). "Greenhouse-gas emissions from solar electric- and nuclear power: A life-cycle study." Energy Policy 35(4): 2549-2557. [102] Gagnon, L. and van de Vate, J. F. (1997). "Greenhouse gas emissions from hydropower : The state of research in 1996." Energy Policy 25(1): 7-13. [103] Gagnon, L., Belanger, C. et al. (2002). "Life-cycle assessment of electricity generation options: The status of research in year 2001." Energy Policy 30(14): 1267-1278. [104] Hunt, T. M. (2000). Five lectures on environmental effects of geothermal utilization. Geothermal Training Programme 2000, Report 1, United Nations University: 109. [105] International Atomic Energy Agency. (2000). Greenhouse Gas Emissions from Electricity Production. [106] Kato, K., Murata, A. et al. (1997). "An evaluation on the life cycle of photovoltaic considering production energy of off-grade silicon." Solar Energy Materials and Solar Cells 47(1-4): 95-100. [107] Komiyama, H., Yamada, K. et al. (1996). "Life cycle analysis of solar cell systems as a means to reduce atmospheric carbon dioxide emissions." Energy Conversion and Management 37(6-8): 1247-1252. [108] Kreith, F., Norton, P. et al. (1990). "A comparison of CO2 emissions from fossil and solar power plants in the ." Energy 15(12): 1181-1198. [109] Lenzen, M. and Munksgaard, J. (2002). "Energy and CO2 life-cycle analyses of wind turbines--review and applications." Renewable Energy 26(3): 339-362. [110] Markandya, A. and Wilkinson, P. (2007). "Energy and Health 2 - Electricity generation and health." Lancet 370(9591): 979-990. [111] Meier, P. (2002). Life-cycle assessment of electricity generation systems and applications for climate change policy analysis. College of Engineering. Madison, University of Wisconsin. Ph.D. Dissertation: 161. [112] Nieuwlaar, E. and Alsema, E. (1998). "PV power systems and the environment: Results of an expert workshop." Progress in Photovoltaics 6(2): 87-90. [113] Nomura, N., Inaba, A. et al. (2001). "Life-cycle emission of oxidic gases from power-generation systems." Applied Energy 68(2): 215-227. [114] Norton, B. (1999). "Renewable electricity - what is the true cost?" Power Engineering Journal 13(1): 6-12. [115] Pacca, S., Sivaraman, D. et al. (2007). "Parameters affecting the life cycle performance of PV technologies and systems." Energy Policy In Press, Corrected Proof. [116] Pehnt, M. (2006). "Dynamic life cycle assessment (LCA) of renewable energy technologies." Renewable Energy 31(1): 55-71. [117] Proops, J. L. R., Gay, P. W. et al. (1996). "The lifetime pollution implications of various types of electricity generation - An input-output analysis." Energy Policy 24(3): 229-237. [118] Rashad, S. M. and Hammad, F. H. (2000). "Nuclear power and the environment: comparative assessment of environmental and health impacts of electricity-generating systems." Applied Energy 65(1-4): 211-229. [119] Schleisner, L. (2000). "Life cycle assessment of a wind farm and related externalities." Renewable Energy 20(3): 279-288. [120] Spadaro, J., Langlois, L. et al. (2000). "Assessing the difference: greenhouse gas emissions of different electricity generating chains." IAEA Bulletin 42(2): 19-24. [121] Tokimatsu, K., Kosugi, T. et al. (2006). "Evaluation of lifecycle CO2 emissions from the Japanese electric power sector in the 21st century under various nuclear scenarios." Energy Policy 34(7): 833-852. [122] Uchiyama, Y. (2007). "Life cycle assessment of renewable energy generation technologies." IEEJ Transactions on Electrical and Electronic Engineering 2(1): 44-48. [123] Uranium Information Centre Ltd, and World Nuclear Association (2003). Nuclear Electricity, 7th edition. [124] Vattenfall (2004). "Summary of Vattenfall AB’s certified environmental product declaration of electricity from the at Ringhals. Environmental product declaration." [125] Vestas Wind Systems, A. S. (2006) "Life Cycle Assessment of Offshore and Onshore Sited Wind Power Plants Based on Vestas V90-3.0MW Turbines." [126] Voorspools, K. R., Brouwers, E. A. et al. (2000). "Energy content and indirect greenhouse gas emissions embedded in `emission-free' power plants: results for the Low Countries." Applied Energy 67(3): 307-330. [127] Weisser, D. (2007). "A guide to life-cycle greenhouse gas (GHG) emissions from electric supply technologies." Energy 32(9): 1543-1559. [128] White, S. W. and Kulcinski, G. L. (2000). "Birth to analysis of the energy payback ratio and CO2 gas emission rates from coal, fission, wind, and DT-fusion electrical power plants." Fusion Engineering and Design 48(3-4): 473-481. [129] Yasukawa, S., Tadokoro, Y. et al. (1992). "Life cycle CO 2 emission from nuclear power reactor and fuel cycle system." Expert workshop on life-cycle analysis of energy systems, methods and experience. [130] dos Santos, M. A., Rosa, L. P. et al. (2006). "Gross greenhouse gas fluxes from hydro-power reservoir compared to thermo-power plants." Energy Policy 34: 481-488. [131] Inhaber, H. (2004). "Water use in renewable and conventional electricity production." Energy Sources 26(3): 309-322. [132] Larson, D., Lee, C., et al. (2007). "California’s Energy-Water Nexus: Water Use in Electricity Generation." Southwest Hydrology September/October: 20-22. [133] Trewin, D. (2006). Water Account Australia 2004-2005, Australian Bureau of Statistics. [134] Younos, T., Hill, R. et al. (2009). Water Dependency of Energy Production and Power Generation Systems. VWRRC Special Report No. SR46-2009, Virginia Polytechnic Institute and State University Blacksburg, Virginia [135] Shafiee, S. and Topal, E. (2009). "When will fossil fuel reserves be diminished?" Energy Policy 37(1): 181- 189. [136] World Nuclear Association. (2006). The New Economics of Nuclear Power. [137] Stefansson, V. (1998). Estimate of the world geothermal potential. Geothermal Training in Iceland 20th Anniversary Workshop, Reykjavik, United Nations University Geothermal Training Programme. [138] Balat, M. (2006). "Current geothermal energy potential in Turkey and use of geothermal energy." Energy Sources Part B-Economics Planning and Policy 1(1): 55-65. [139] International Energy Agency. (2000). The Potential of Wind Energy to Reduce CO2 Emissions. International Energy Agency Greenhouse Gas R&D Programme. Paris. [140] Sen, Z. (2004). "Solar energy in progress and future research trends." Progress in Energy and Combustion Science 30(4): 367-416. [141] BP. (2008). "Statistical Review of World Energy 2008." from http://www.bp.com/statisticalreview accessed 10/03/2009. [142] IEA . (2007). Potential Contribution of Bioenergy to the World's Future Energy Demand. [143] Kaygusuz, K. (2002). "Sustainable development of hydropower and biomass ." Energy Conversion and Management 43(8): 1099-1120. [144] Parikka, M. (2004). "Global biomass fuel resources." Biomass and Bioenergy 27(6): 613-620. [145] Clean Energy Council. (2008). Biomass Resource Appraisal, Clean Energy Council. [146] Archer, C. L. and Jacobson, M. Z. (2007). "Supplying baseload power and reducing transmission requirements by interconnecting wind farms." Journal of Applied Meteorology and Climatology 46(11): 1701-1717. [147] Egre, D. and Milewski J. C. (2002). "The diversity of hydropower projects." Energy Policy 30(14): 1225- 1230. [148] Bertani, R. (2005). "World geothermal power generation 2001-2005." Geothermics 34(6): 651-690. [149] Abbasi, S. A. and Abbasi, N. (2000). "Likely adverse environmental impacts of renewable energy sources." Applied Energy 65(1): 121-144. [150] Wolsink, M. (2007). "Wind power implementation: The nature of public attitudes: Equity and fairness instead of `backyard motives'." Renewable and Sustainable Energy Reviews 11(6): 1188-1207. [151] Wolsink, M. and Sprengers, M. (1993). "Windturbine noise: a new environmental threat? ." Noise as a public health problem 2: 235-238. [152] Li, F. (2002). "Hydropower in China." Energy Policy 30(14): 1241-1249. [153] Mailman, M., Stepnuk, L. et al. (2006). "Strategies to lower methyl mercury concentrations in hydroelectric reservoirs and lakes: A review." Science of the Total Environment 368: 224– 235. [154] Rybach, L. (2003). "Geothermal energy: sustainability & the environment." Geothermics 32(4-6): 463-470. [155] Fridleifsson, I. B. (2001). "Geothermal energy for the benefit of the people." Renewable & Sustainable Energy Reviews 5(3): 299-312. [156] Baba, A. and Armannsson, H. (2006). "Environmental impact of the utilization of geothermal areas." Energy Sources Part B-Economics Planning and Policy 1(3): 267-278. [157] Møller, I. S. (2006). Criteria and indicators for sustainable production of forest biomass for energy. IEA Bioenergy EXCO58 Meeting. [158] Raison, R. J. (2006). "Opportunities and impediments to the expansion of forest bioenergy in Australia." Biomass and Bioenergy 30(12): 1021-1024. [159] Clapp, R.W.(2005). "Nuclear Power & Public Health." Environment Health Perspectives 113(11): 720-721. [160] Bithell, J. F., Dutton, S. J. et al. (1994). "Distribution of childhood leukaemias and non-Hodgkin's lymphomas near nuclear installations in England and Wales." British Medical Journal 309(6953): 501-506. [161] Brown, V. J. (2007). "Childhood leukemia in Germany: cluster identified near nuclear power plant.(Science Selections)." Environmental Health Perspectives 115(6): A313. [162] Hoffmann, W., Terschueren, C. et al. (2007). "Childhood leukemia in the vicinity of the Geesthacht nuclear establishments near Hamburg, Germany." Environmental Health Perspectives 115(6): 947-952. [163] Mangano, J. J., Sherman, J. et al. (2003). "Elevated childhood cancer incidence proximate to U.S. nuclear power plants." Archives of Environmental Health 58(2): 74-82. [164] ABARE (2009) “ 2009”. Australian Government Department of Resources, Energy and Tousirm.