Solar Power

Solar panel electricity is generated when the sun hits a solar panel and is converted to electricity. All solar panels are made from treated silicon cells, but there are slight variations in production methods. Solar panels are usually one of three types.

Monocrystalline panels are made from a thin slice cut from a single, very large crystal of silicon. The crystal itself is cut from an even larger ingot of silicon. Because of the use of only one crystal, these are the most expensive. However, they are the most efficient.

Polycrystalline panels are blocks of silicon that contain many small crystals. The polycrystalline cells are sliced from a cast silicon block and have an appearance of shattered glass. The cells are linked together into a panel. Although slightly less efficient than the monocrystalline panels, the difference is minor.

Amorphous panels are the "thin film" panels, where a thin film of silicon is spread over some other material, either rigid or flexible. Amorphous panels are noticeably less efficient than the other two types, which means you have to have a larger panel to generate the same electricity as a mono- or polycrystalline panel.

Silicon is a semiconductor, meaning it serves as an "intermediary", allowing electrons to move between positive and negative fields. Silicone is always sandwiched with some other material, often stainless steel. One surface has a positive field, the other a negative field. When sunlight hits the silicon, electrons move between the two fields, creating electricity.

However, solar cells generate direct current, or DC, the same kind produced by batteries. Your household appliances, lights, etc, typically run on alternating current or AC. Somewhere between the solar panel and your light bulb, that current needs to be converted. For that you would purchase an inverter.

Currently, solar panel electricity is more expensive than electricity purchased from the "grid". A standard watt of electricity costs, on average, $2.00. A solar-generated watt of electricity runs somewhere around $4.50 to $5.00. However, this is much, much lower than the over $12 per watt it cost in California in 1998.

Electricity generated by solar panels has other advantages that are bringing it into mainstream American homes, though. No rivers need to be dammed up or fish killed. No coal is burned or pollution produced. Our fossil fuel reserves are not depleted.

For many people, these "ancillary" benefits reduce the cost of solar-generated electricity enough that they consider installing a system. Also, many utilities offer a variety of rebates and financing options to further sweeten the pot, so to speak.

Research is underway around the world to bring technological advances to solar panel technology. Within a few years we should see the cost per watt of solar energy approach that of electricity from the grid. At a competitive cost, solar power may help us turn the corner toward an independent energy future.