References: NREL, 2009, Learning about Renewable Energy, Available at: http://www.nrel.gov/learning/ . [Accessed 20/11/2011]. NREL, 2009, Hydrogen Basics, Available at: http://www.nrel.gov/learning/eds_hydrogen.html . [Accessed 20/11/2011]. NREL, 2009, Solar Energy Basics, Available at: http://www.nrel.gov/learning/re_solar.html [Accessed 20/11/2011]. NREL, 2009, Geothermal Energy Basics, Available at: http://www.nrel.gov/learning/re_geothermal.html. [Accessed 20/11/2011]. Clean Energy Ideas, 2011, Natural and Renewable Energy resources, Available at: http://www.clean-energy-ideas.com/ .[Accessed 20/11/2011]. Clean Energy, 2011, Why Natural Gas is Today’s Best Alternative Vehicle Fuel, Available at: http://www.cleanenergyfuels.com/straight.html. [Accessed 20/11/2011]. Ned Haluzan, Renewable Energy Articles, 2010, Clean Energy Definition, Available at: http://www.renewables-info.com/energy_definitions/clean_energy_definition.html .[Accessed 20/10/2011]. “U.S. Department of Energy”, 1997. National Renewable Energy Laboratory [Online], Available at: http://www.nrel.gov/docs/legosti/fy97/20505.html pdf.[Accessed 20/11/2011]. Science online. 2001. Renewable energy resources. [ONLINE] Available at: http://www.scienceonline.co.uk/energy/renewable-energy.html . [Accessed 20/11/2011].
References: NREL, 2009, Learning about Renewable Energy, Available at: http://www.nrel.gov/learning/ . [Accessed 20/11/2011]. NREL, 2009, Hydrogen Basics, Available at: http://www.nrel.gov/learning/eds_hydrogen.html . [Accessed 20/11/2011]. NREL, 2009, Solar Energy Basics, Available at: http://www.nrel.gov/learning/re_solar.html [Accessed 20/11/2011]. NREL, 2009, Geothermal Energy Basics, Available at: http://www.nrel.gov/learning/re_geothermal.html. [Accessed 20/11/2011]. Clean Energy Ideas, 2011, Natural and Renewable Energy resources, Available at: http://www.clean-energy-ideas.com/ .[Accessed 20/11/2011]. Clean Energy, 2011, Why Natural Gas is Today’s Best Alternative Vehicle Fuel, Available at: http://www.cleanenergyfuels.com/straight.html. [Accessed 20/11/2011]. Ned Haluzan, Renewable Energy Articles, 2010, Clean Energy Definition, Available at: http://www.renewables-info.com/energy_definitions/clean_energy_definition.html .[Accessed 20/10/2011]. “U.S. Department of Energy”, 1997. National Renewable Energy Laboratory [Online], Available at: http://www.nrel.gov/docs/legosti/fy97/20505.html pdf.[Accessed 20/11/2011]. Science online. 2001. Renewable energy resources. [ONLINE] Available at: http://www.scienceonline.co.uk/energy/renewable-energy.html . [Accessed 20/11/2011].