Solar power plants are facilities where sunlight is converted into electrical energy for use in our day to day activities. The conversion of sunlight to electric energy can be done either directly or indirectly. The direct means of conversion involves the use of photovoltaics while the indirect means of electricity generation is via concentrated solar power (CSP).
There are several ways by which the sun’s energy can be harnessed and used to generate electricity. Some of these methods and techniques are outlined below;
Solar Thermal Power Plants: such solar power plants use the energy collected from the sun to generate steam which is then used to power a turbine and eventually generate electricity. There are three distinct methods by which these plants collect solar energy and they are outlined below;
- Linear parabolic trough systems
- Linear concentrating systems (i.e. Fresnel reflectors)
- Solar dishes and engines
Solar power towers: this method of solar energy collection involves the use of several hundreds or thousands of heliostats (these are flat mirrors that track the sun so as to get the maximum amount of sunlight possible) to direct the sun’s energy towards a central tower. Solar power towers are effective in the collection of solar energy as they have the ability to greatly enhance the intensity of sunlight received. Sunlight collected using this method can be concentrated to as much as 1,500 times direct sunlight.
Solar power towers generate electricity by using the solar energy collected to heat the air in the tower. The air thus heated is then used to generate steam via a boiler. The steam thus generated is subsequently used to power a turbine and generate electricity. Some solar power towers utilize water as the means of transferring heat as opposed to air.
Solar power towers can store energy which means that they can produce electricity even during cloudy days and overnight. They are also sturdy and tough which makes them very well suited for locations that have severe weather conditions.
Photovoltaics: photovoltaic solar power plants utilize expansive areas of photovoltaic cells (these are light sensitive cells that can convert solar energy to electricity) to produce electricity. This is done through the immediate conversion of sunlight to electricity.
Photovoltaic cells are manufactured using silicon alloys and they take different shapes which include the following;
Crystalline solar panels: this type of photovoltaic panels are created using crystalline silicon. There is the monocrystalline variant (which is more expensive) and the poly- or multi-crystalline variant. The monocrystalline variant is more effective and efficient than its counterpart.
Thin-film solar panels: this photovoltaic panels offer flexibility and can thus be applied in a variety of ways through incorporation. An example is integration with house roofing tiles. Thin-film solar panels use a number of light absorbing films to capture sunlight which is then converted into electricity. The materials used includes amorphous silicon, copper indium, diselenide etc.
Solar pond: this type of solar power plant makes use of a pond containing saltwater. With the aid of a technique known as salinity-gradient technology, the sun’s energy is harvested and stored within this pond.
With awareness increasing as to the benefits of renewable energy as well as the many havoc we are wreaking on the planet, attention is shifting to alternative methods of energy production such as solar power. This sector has seen rapid growth in the past few years with more expected in the years to come.