How solar power works
You may not know it, but the sun is a huge power plant. In fact, just a tiny fraction of the sun’s power is far greater than all of the power plants on the face of our planet. When we harness the power of the sun we do a lot of great things – from reducing carbon and other emissions, to saving the resources of our planet, to lowering our dependence on foreign oil and more. But best of all, using a solar solution can save you a lot of money!
You can feel the energy of solar power – just go outside on a sunny day and you’ll feel the warmth of the sun on your back. That’s the sun’s energy. Unlike you, however, there are some materials that, when exposed to the energy of the sun, turn that energy into electricity. Understanding this concept is the start of understanding how solar power works.
Materials that turn the sun’s energy into electricity
In the old days, solar technology used large crystals made out of silicon to produce electricity. When the silicon crystal is exposed to light, the electrons actually move around rather than the more common response in other materials of just shaking back and forth. When electrons are “shaking back and forth” the effect is to cause heat; but when they start moving about, the effect it to create electricity. That electricity can be harnessed to generate power. It may surprise you that solar energy solutions have been around since the 1950’s with the first real applications being for use in generating power in space in the 1960’s. It’s very expensive to grow those large silicon crystals, however, and that’s why it has taken many years to bring down the cost of solar and make it affordable for residential applications.
Fast-forward to today and solar power is starting to take off. The reason is the development of cheaper electric generating crystals that can be shaped into films that have flexibility and are more easily used in all manner of applications. When manufactured into a cell to capture the sun’s light and create electricity, the cells are known as Photovoltaic cells (or PV cells for short).
Current capabilities of solar cells
While PV cells are getting cheaper and more efficient, they are still not where scientists would desire. Current residential applications – those that are cost effective enough to put on a rooftop are able to convert light into electricity with a 15% to 20% efficiency. Conversely, the most expensive and effective PV cells can do the same conversion at around 50% efficiency. New materials are being tested and evaluated all the time and there is little doubt that, over time, solar cells will become more and more efficient.
The good news is that the cost for a home solar solution is now affordable for most homeowners; and the efficiency means that the savings on electricity can both help pay off the cost of the solar solution and increase the value of a home. With electricity rates rising each year about 7% or so, the savings can be dramatic over 10, 15, or 20 years.