Solar Panels: What Exactly Are They, and How Do They Do What They Do?

The type of solar panels that are used for electricity are flat panels made up of photovoltaic cells, which are tiny, crystalline, semiconductor structures made from silicon, with boron and phosphorous added. The boron and phosphorous create a positively charged region and a negatively charged region within the cell that produce a current when stimulated by the sun's rays. Solar panels that are used for heating do not have cells but are specially designed to absorb heat from the sun. The energy generated is then used for hot-water heating.

The ideal location for a solar energy system is one that has space for enough panels to make the system worthwhile, is exposed to little or no shading from trees or surrounding buildings, and allows the panels to face south (although east and west are also acceptable in some cases). When used to generate electricity, a solar system needs to be connected to the electrical power grid and thus will automatically shut down when power to the grid fails. However, a battery backup system may be used to store a portion of the solar-generated electricity.