How Solar Energy Works
Solar for Your Home
Solar for Your Business
How Do Solar Panels Work?
In addition to being the ultimate source of all life on earth, the sun is an infinitely renewable, completely pollution-free source of electricity. Instead of burning fossil fuels dug up from the ground in a big power plant – a very 19th century, industrial age approach, when you think about it – solar panels convert sunlight directly into electricity, with no harmful emissions.
The basic unit of a solar panel is a solar cell, which usually consists of one or two layers of silicon-based semiconductor wafers. When struck by the photons in sunlight, the solar cell generates an electrical charge due to the "photovoltaic effect" – which is a pretty good name, since it produces voltage from photons. The flow of these electrons moves in a steady electrical current from one side of the cell to the other.
Dozens of these PV cells are packaged together into solar modules, which in turn are packaged into solar panels that are mounted on a rooftop and arranged to maximize their hours of exposure to direct sunlight. Because the electricity generated by all those solar cells is direct current (DC), it is then sent to an inverter that transforms the power into the same alternating current (AC) used by the appliances in your home and the local utility electricity distribution grid. Increasingly, these inverters are getting "smart," providing data monitoring for solar installation performance and other grid integration services.
This compatibility with the grid is important, because for a variety of reasons most solar homes only use solar to provide a portion of their electricity needs, relying on local utility supplies for backup when the sun isn't shining or if extra power is needed. The electricity produced by these panels is integrated seamlessly into your existing electricity service, so you can go solar without having to worry about your lights dimming every time a cloud passes overhead.
Not Cutting the Cord – Lowering Your Energy Costs
Understanding that solar panels work with your existing electricity service instead of replacing it completely is key to understanding the economics behind the solar boom. Solar panel prices have plummeted in recent years, as the industry achieves greater and greater economies of scale – much like the production of computer chips, which makes sense since both technologies rely on silicon-based semiconductors. These declining costs for solar panels are a big reason why solar PV is everywhere these days, whether as part of your solar-charging backpack or huge power plants in the desert.
The home solar boom isn't just about the price of the panels themselves though – it's also about the availability of solar financing that allows homeowners to pay for those solar panels (and their installation) in regular installments over a long period of time, instead of paying for everything up front. These payments are usually lower than what they pay for the equivalent amount of electricity from their utility. Thus, instead of paying one big utility bill every month, you pay a smaller combined amount from the payments on your solar system plus a much lower utility bill.