by Matt McCormack

Created on: July 04, 2007   Last Updated: January 16, 2008

In a single hour the sun delivers us more energy than what the entire planet consumes in one year. Although the sun is a huge power source, the challenge for scientists is to develop technology that will efficiently collect and harness this energy. Solar technology has evolved, today it is much more than the blue panels you see on calculators and road signs. It will most likely be our major energy source in the future.

SOLAR COLLECTION:
Solar thermal technology is predicted to be the future for solar power. It works on the century old principle of using steam to spin a turbine to generate electricity, but entails the sun to heat the water, rather than coal. But as strange as it sounds, some coal power stations have adopted solar thermal technology.
The Liddell power station in Australia will become one of the first hybrid power plants using both coal and the sun to produce electricity. The station will use the sun's energy to preheat water which will reduce the amount of coal needed to make steam. This will increase the plants efficiency and cuts greenhouse gas emissions. Solar thermal technology can still work very effectively without fossil fuels.

The world's first commercial solar tower was commissioned in Spain earlier this year. It uses a field of 600 steel reflectors, acting as mirrors that track the sun's rays and direct them to a focus point on a 377 ft (115 m) tower. The reflectors can magnify the sun's energy as much as 1500 times and reach temperatures over 750 Fahrenheit (400 C). This heat is then used to power a boiler that can generate up to 10 Megawatts of power enough to power 6000 homes. An even bigger 20MW solar thermal tower is currently being developed.

The most common form of solar collection at the moment is through photovoltaic cells which are the blue colored panels found in calculators. These cells, developed 50 years ago, are made from silicon and are designed to absorb the sun rays. A complex molecular reaction takes place in the cells, which in turn converts the sunlight directly into electricity that can be distributed through the electricity grid.

STORAGE:
A major downside of solar power is that the sun doesn't shine all the time. This means that another power source is needed to supplement solar technology or solar energy needs to be stored. Until recently the main method of storing solar power has involved using large batteries. These batteries are very expensive and have made solar energy less viable.

In Europe a new storage method has been developed where the gas Ammonia is heated. The heat splits the gas into hydrogen and nitrogen which are stored separately. When the two gasses are recombined they give off the same heat that was originally used to separate them which can be as hot as 900 F (500 C). This has made storage much more viable and compatible with solar thermal technology.

ECONOMICS:
The cost of solar technology is around 3 times the price of standard electricity and is currently not regarded by many governments as a viable alternative to fossil fuels. However there is optimism that this will change, firstly further developments and investment in these technologies can bring the price down. Also, With the threat of global warming most countries have adopted emissions trading schemes (such as those established under the Kyoto Protocol), as well as carbon taxes and other measures that will put a price on carbon emissions. These measures will make solar energy much more competitive with fossil fuel technologies in the future. So there is still a very bright future ahead for solar technology.

Learn more about this author, Matt McCormack.
Click here to send this author comments or questions.