This is a common question that I get asked quite often. You know the meaning of “solar” but what does exactly “PV” mean?
Well, PV stands for Photovoltaics. That’s the term used in physics which describe how light rays turn in to electricity. This theory explains that there are special types of materials (semiconducting materials) which emit free electrons once they get illuminated by sunlight. A flow of free electrons means, electric current.
It is actually the visible light rays of the whole solar radiation spectrum that is responsible for electric current making. Some people think that solar panels need heat to make energy. No, it is not heat, it’s the light rays that make energy out of solar panels. Wave forms closer to visible light rays like UV and infrared does not help making electricity in solar panels.
But there are other technologies which we use solar thermal energy for making electricity. That is a totally different technology other than solar PV. It is called Solar Thermal Energy. A good example for solar thermal energy is the solar hot water unit on your roof. They use solar thermal energy to heat up water.
There are mega scale solar thermal electricity plants in the world also. They use solar thermal energy to heat up water to get high pressure steam and then, this steam drives an electric turbine. This is how these solar thermal plants are operating.
So, don’t get confused now, solar PV and solar thermal energy are 2 different technologies.