The sun provides enough energy in one minute to supply the world's energy needs for one year. In one day, it provides more energy than our current population would consume in 27 years. Solar energy is a free, inexhaustible resource, yet utilizing it is a relatively new idea.
Solar energy had great potential, but it was left on the backburner whenever fossil fuels were more affordable and available.
We use solar power in the same two forms today, thermal and photovoltaic. The first concentrates sunlight, converts it into heat, and applies it to a steam generator or engine to be converted into electricity in order to warm buildings, heat water, generate electricity, dry crops or destroy dangerous waste. Electricity is generated when the heated fluid drives turbines or other machinery. The second form of solar power produces electricity directly without moving parts. Today's photovoltaic system is composed of cells made of silicon, the second most abundant element in the earth's crust.
There are several advantages of solar power that make it one of the most promising renewable energy sources in the world. It is non-polluting, has no moving parts that could break down, requires little maintenance and no supervision, and has a life of 20-30 years with low running costs. It is especially unique because no large-scale installation is required. Remote areas can easily produce their own supply of electricity by constructing as small or as large of a system as needed. Solar power generators are simply distributed to homes, schools, or businesses, where their assembly requires no extra development or land area and their function is safe and quiet. As communities grow, more solar energy capacity can be added. Compare those characteristics to those of coal, oil, gas, or nuclear power, and the choice is easy. Solar energy technologies offer a clean, renewable and domestic energy source.
Photovoltaic power even has advantages over wind power, hydropower, and solar thermal power. The latter three require turbines with moving parts that are noisy and require maintenance.
Solar energy is most sought today in developing countries, the fastest growing segment of the photovoltaics market. It is much more practical than the extension of expensive power lines into remote areas, where people do not have the money to pay for conventional electricity.
Solar power is just as practical in populated areas connected to the local electrical power grid as it is in remote areas. The average home has more than enough roof area to produce enough solar electricity to supply all of its power needs. With an inverter, which converts direct current (DC) power from the solar cells to alternating current (AC), which is what most home appliances run on, a solar home can look and operate very much like a home that is connected to a power line.
There are only two primary disadvantages to using solar power: amount of sunlight and cost of equipment. The amount of sunlight a location receives can vary greatly depending on geographical location, time of day, season and clouds.
The best way of lowering the cost of solar energy is to improve the cell's efficiency. As the price of solar power lowers and that of conventional fuels rises, photovoltaics will enter a new era of growth. Solar power will remain an excellent energy option.