Solar Power

The sun provides all of the energy for life on Earth, powering plants, animals and human activity.

Solar power systems allow us to generate electricity from sunlight. This can be direct conversion through photovoltaics or indirect through mirror arrays. Photovoltaics are small cells that convert solar radiation into a stream of charged electrons. These photovoltaic cells can be grouped together in mass quantities on solar panels, and installed on any scale, from households to industrial solar power plants.

Solar power can be harnessed indirectly, such as by concentrating the sun’s power to a central point using reflective mirrors, and then using that central point as a super-heated engine to boil water, spin a rotor and generate electricity.

Another way of harnessing the sun’s energy is through passive solar power. This involves techniques like orienting windows towards the Sun to warm buildings naturally, or designing spaces that naturally circulate air in order to use solar energy more efficiently.

Solar power is now the world’s fastest growing renewable energy technology. In the four years between 2004 and 2009, solar photovoltaic capacity multiplied nearly sixfold to more than 16 gigawatts globally under construction.

Using the sun’s energy to power an electricity generator avoids greenhouse gas emissions. That means that solar power could be a carbon-neutral alternative to burning fossil fuels to produce energy. Once solar panels have reimbursed their initial energy input, roof-top solar can avoid 40 tonnes of CO2 emissions each day by replacing fossil fuel sourced energy. That means that solar energy could play an important role in stopping climate change.

Although solar power has been widely recognised as part of the solution to climate change, it still faces various criticisms. Some people point out that solar panels are less efficient and more costly compared to fossil fuels.

One response to these criticisms is that more research is needed to make solar power more efficient and less expensive. Right now fossil fuels are a cheaper source of energy, but that is partly because governments have traditionally subsidised infrastructure and research and development into fossil fuel technology.

In the US alone, government subsidies for the fossil fuel industry reached US$72 billion from 2002 to 2008, while the solar industry received less than US$1 billion in assistance. Clearly more money is needed to improve solar power technology.

Many governments already help to subsidise the costs of installing solar panels in homes, schools and businesses. In terms of efficiency, home solar power systems already produce around 17 times the amount of energy needed to create and install them.

Another debate around solar power is that the sun’s energy, obviously, is only available during the day. However that does not mean that electricity from solar power is restricted to daylight hours only. Solar energy can be stored, such as in molten salts, which store solar energy in the form of heat which can be used to make energy during the night or on very cloudy days.

References

Renewable Energy Policy Network, ‘Renewables Global Status Report’, 2010, http://www.ren21.net/Portals/97/documents/GSR/REN21_GSR_2010_full_revised%20Sept2010.pdf

Energy Matters, ‘Solar Panel Myths – Climate Change Contributors’, 20 October 2009, http://www.energymatters.com.au/index.php?main_page=news_article&article_id=631

Geoffrey Styles, ‘Can Solar Compete?’, 3 September 2009, Scitizen, http://scitizen.com/stories/future-energies/2009/09/Can-Solar-Compete/

Daniel Kessler, ‘Solar Industry Says End Fossil Fuel Subsidies And Expect A Solar Boom’, 29 Debember 2009, http://www.treehugger.com/files/2009/12/solar-industry-fifteen-percent.php#comments

Energy Matters, ‘Solar Panel Myths – Climate Change Contributors’, 20 October 2009, http://www.energymatters.com.au/index.php?main_page=news_article&article_id=631

Todd Woody, ‘Generating Solar Power After Dark’, The New York Times, 26 December 2009 http://greeninc.blogs.nytimes.com/2009/12/26/hold-for-playback/