Posts Tagged ‘solar power’

solar power

August 30th, 2010

Solar power involves harnessing the sun’s energy to produce electricity. The main advantage of solar power is that the generation of electricity does not produce any of the greenhouse gases responsible for climate change. It is also a renewable energy source and does not rely upon the use of fossil fuels.

Despite the tremendous benefits of solar power, there are also some negative consequences. Construction of solar power infrastructure produces outputs that are not environmentally friendly. Building, operating and maintaining solar power technologies also impact upon local flora, fauna and ecosystems. As with most human activities, there will always be a level of ecological impact or footprint. It is just the degree and type of impact that needs to be considered.

The conversion of solar energy into electricity can involve the use of photovoltaics and the concentration of solar thermal power.

Photovoltaics

The use of solar energy is on the increase. Even in household applications, solar power is being used for the simplest of tasks. From lighting letterboxes to decorative garden lights to powering water features, the use of solar power generation in our daily lives has really taken a turn. We just need to look outside of our homes for all the wonderful ways solar is being used, such as powering road signs and lighting up sea buoys. In the main, photovoltaics are the type of solar power that is most often come across by the average consumer.

Photovoltaics involve the sun being turned directly into electricity. Photovoltaic cells comprise of a semiconductor substance (e.g. silicon). Through a series of processes, electrons are freed and electricity is produced as a result. Although there are problems associated with photovoltaics, such as the small voltages produced, they also have many benefits. The most significant advantage of solar power is that it relies on an abundant resource – one that cannot be depleted. Photovoltaics are also quiet to run and are reliable.

Concentrating Solar Thermal Power

The ability to concentrate solar energy is a simple idea in theory. This form of electricity generation involves using the sun to heat up fluid encased in a receiver. The liquid is heated up to such a high temperature that steam is produced as a result. This steam, in turn, powers a turbine and produces electricity in an attached generator.

There are particular advantages of using concentrated solar thermal power; that is, it is less expensive than other types of solar generation. Perhaps the major advantage to solar thermal technology is that it can be “hybridized”. It can be mixed with fossil fuel technologies and stored. There is much excitement amongst the scientific community over concentrated solar thermal power and its potential.

There are different methods for capturing concentrated solar thermal power, some of which include: Parabolic Troughs; Dishes; and, Solar Tower. Parabolic troughs involve mirrors that are used to concentrate the sun onto receiver tubes. These tubes heat up the fluid and power a turbine to generate electricity. The Dish used in harnessing concentrated solar thermal power also involves mirrors to concentrate the sun onto a position (receiver) on a dish. The heated fluid in the receiver powers a small engine to produce electricity. Solar Towers are also used to concentrate solar thermal power. These towers involve the use of mirrors that track the sun. The receiver is located on the top of the tower and the mirrors concentrate the sun.

Despite humankind employing solar energy technology throughout history, it’s almost as though it had been forgotten – with the more efficient fossil fuels taking its place. Since concern over greenhouse gases and depletion of fossil fuels reserves, however, solar and many of the renewable energy sources have experienced a revival. Scientists are only just beginning to make considerable technological advancements that will help our society transition into using renewable energy as a mainstream energy source.