Solar energy is the oldest form of renewable energy known to man and is the cornerstone of many renewable energy projects across the globe. It is also the subject of great debates over its usefulness.
Variously described as wasteful, inefficient and expensive, increasing costs for fossil fuels could bring about a popular return to solar energy – long heralded as the energy of the future. This article will give you a background to what could be one of the energies of tomorrow.
What is Solar Energy?
Architects and farmers have long considered how to site their buildings and fields to make sure they benefit from optimum sunlight. Solar energy and solar power are now usually used to describe the conversion of the Sun’s rays into electricity, and then used for running households, powering factories and heating or cooling offices.
How solar energy works
The conversion of sunlight to electricity is achieved via one of three processes.
- Concentrating solar power (CSP) systems concentrate light into beams and focus them onto panels that can then be used to power conventional conversion systems. The most common achieve this by focusing the light to convert water into steam.
- The second process, known as photovoltaics, utilises the Sun’s rays to generate a voltage through ejecting electrons from a material’s surface.
- Finally, solar chemical systems use the light rays or heat energy from the Sun to trigger chemical reactions, in turn producing extra energy.
Advantages of solar energy
Solar power provides a clean, reliable and renewable source of energy for people living in areas with long hours of sunlight throughout the year. Although the cost of setting up solar energy projects is expensive, the cost of maintaining solar energy farms is remarkably cheap. Large solar farms can also be sited in areas previously of little use to humans, such as arid deserts and barren mountains. It can provide an endless supply of cheap energy rendering it particularly popular with green activists and governments alike.
Disadvantages of solar energy
The cost of manufacturing and installing the panels and converters required to harness solar energy is close to astronomical. Many governments are forced to provide subsidies to those interested in setting up solar energy plants in order to make their endeavour economically viable. Even with rising fuel and gas prices, fossil fuels remain relatively cheap alternatives. A 2006 Australian study estimated that solar thermal energy cost 85 Australian dollars per megawatt hour and photovoltaics $120 per megawatt hour compared with 28-38$ for coal. Similarly, current technologies for solar panels are relatively inefficient. The most advanced ones on the market only manage to convert 22% of the rays, which hit them into useable energy. This means solar energy plants need to be enormous to make financial sense - a problem given many consider them eyesores and would like them kept away from both urban and picturesque natural environments.
Future of Solar Energy
Often derided as inefficient, the rising price of oil has rendered solar power ever more attractive to those searching for guaranteed and safe sources of cheap energy. Still, most new projects rely on some form of government funding to get them started because of the high initial cost of installing the equipment necessary to see any meaningful reduction in reliance on fossil fuels. This could be about to change. New technologies in the pipeline could improve on the efficiency of current machinery by 20 to 40 times. Such advancements could make this most ancient energy form a fuel of the future.
Most governments offer subsidies to set up solar projects, though these often vary in size and suitability. In Australia, many states have set up ‘feed-in tariffs’. The tariffs pay producers of renewable energy a premium for what they produce. This is done to keep compliance with the mandatory renewable energy targets requiring 20% of energy produced in Australia to come from renewable sources by 2020.
Solar Power around the World
Many countries have embarked on ambitious solar energy projects, with the lion’s share being undertaken by those situated close to the equator enjoying long hours of sunlight all year round such as Italy, Spain and China. However, this is not always the case – Germany is a leading country in terms of volume produced in spite of its northern location and limited sunshine. Moreover, some remain undecided on the merits of solar energy, choosing instead to search for their renewable energy elsewhere.
Leading companies involved in solar energy production include Suntech, JA Solar, Sharp, Bosch, BP, Canadian Solar and China Sunergy, most of whom are focused on photovoltaics.
Whilst solar energy has a long way to go before it can fulfil all of man’s energy needs, it seems that such power is here to stay and will be a part of any renewable energy drive for the future.
Visit our Alternative Energy section for more articles about renewable energy sources.