Before learning about the future of solar energy we must first look at how solar energy currently works. There is essentially only one way to produce electricity through solar power that is commercially available to most people. This is through a Photovoltaic cell.
The photovoltaic cell starts with polycrystalline silicon (also known as polysilicon or poly-Si). This is a high purity, crystalline form of silicon. When polysilicon itself is irradiated by sunlight, some of the electrons on the silicon start to get knocked off and become free electrons. The amount of free electrons produced however is very low, and nowhere near enough to efficiently produce electricity. Scientists and engineers however, have found a way to essentially turn the polysilicon into a solar 'battery' by lacing the polysilicon with impurities (doping) to make it either positively or negatively charged and 'sandwiching' them together to create an electric field similar to batteries.
The photovoltaic cell starts with polycrystalline silicon (also known as polysilicon or poly-Si). This is a high purity, crystalline form of silicon. When polysilicon itself is irradiated by sunlight, some of the electrons on the silicon start to get knocked off and become free electrons. The amount of free electrons produced however is very low, and nowhere near enough to efficiently produce electricity. Scientists and engineers however, have found a way to essentially turn the polysilicon into a solar 'battery' by lacing the polysilicon with impurities (doping) to make it either positively or negatively charged and 'sandwiching' them together to create an electric field similar to batteries.
Although photovoltaic cells themselves are very similar, there are various strategies for capturing sunlight that makes each photovoltaic cell more efficient. For example most solar power plants use a way of concentrating solar energy conveniently called 'Concentrated Solar Energy'.
One of the most common versions of concentrated solar energy involves the use of mirrors to concentrate and direct the suns rays toward one point where the energy is more easily collected.
To the right is one example of concentrated solar energy. In this case sunlight is directed to the top of a tower, where it's collected. Although constructing these soar power plants is very expensive, they are many times more efficient than normal photovoltaic cells. |
Another interesting way of collecting solar energy surprisingly involves no photovoltaic cells.
In this type, large parabolic-half cylinders are built with a pipe in the center. During the day sunlight is directed towards the pipe heating oil inside. Eventually the oil in the pipes get so hot that when its poured into a vat of water, the water vaporizes. This steam spins a turbine that produces electricity (similar to the way nuclear power plants produce energy.
In this type, large parabolic-half cylinders are built with a pipe in the center. During the day sunlight is directed towards the pipe heating oil inside. Eventually the oil in the pipes get so hot that when its poured into a vat of water, the water vaporizes. This steam spins a turbine that produces electricity (similar to the way nuclear power plants produce energy.
No matter how solar energy is collected, you inevitably run into the same problem: Darkness. Whether its night, or just a cloudy day, solar power obviously cannot be collected when there is no sun to draw from. Unfortunately this problem has yet to be efficiently solved. Although there are endless ways to store energy to be used when there is no sunlight, it just ends up being too expensive be readily implemented. Further knowledge in physics is required to solve this currently unsolvable problem.