How is solar energy is better than thermal power
Answers
Solar energy comes from the sun. It drives the weather and feeds plants on Earth. In more specialized terms, solar energy refers to the technology that allows people to convert and use the energy of the sun for human activities. Part of the sun’s energy is thermal, meaning it is present in the form of heat. Some approaches to solar power convert the sun’s energy to heat, but for other approaches heat does not help at all. There are also other definitions of thermal energy that have nothing at all to do with the sun.
The word "thermal" derives from the Greek word for heat, so thermal energy is technically heat. When engineers talk about thermal energy it is usually a bad thing -- waste. For example, an incandescent light bulb puts out light, but it actually puts out more heat than light. When your laptop computer warms your lap, that does nothing to help you do calculations -- it is wasted energy. This wasted energy is almost everywhere -- car engines, cellphones, televisions. This form of thermal energy has nothing to do with the sun.
There are two general approaches to extracting energy from sunlight. The first approach is called photovoltaic. In the photovoltaic approach, sunlight is captured in a semiconductor material and the semiconductor puts that energy right into its electrons. When the electrons are pulled out and sent through a circuit, they directly provide electrical energy. As long as the sun shines, the electricity comes out. Most solar panels work better when they are cooler -- so when they collect too much of the sun's thermal energy, it is a problem. This is solar energy that is not thermal energy.