What Are Solar Power Farms?

Solar power farms are large-scale commercial power plants that create clean energy from the sun. They are typically located in desert climates where sunshine is plentiful and the land is cheap. These industrial-sized installations, costing millions of dollars, are usually constructed and developed by electric utilities or by government-sponsored technology experiments.

Electricity can be generated by three types of solar power farms:

  1. Solar cells, or photovoltaic cells, can create direct current (DC) electricity from sunlight without using a turbine or generator. Using semiconductor material, these solar cells are the most expensive way to create power.

  2. Reflecting sunlight onto a centralized tower which in turns heats a fluid to super-hot temperatures. This fluid, usually iodized salt, can reach over 1000 degrees Celsius which is than used to create steam to turn a turbine.

  3. Smaller, parabolic mirrors can also be used to concentrate sunlight to a focal point where a fluid is heated or to energize an efficient electric generator (a Sterling engine).

One of the largest of these farms will create enough power for 21,000 homes (about 80 MegaWatts). It is estimated to require about 640 acres of land in the California desert.

To make solar farms like this viable, the following considerations must be addressed:

  • Solar power plants only produce electricity during daylight hours so their payback time is less then other forms of power generation. Since it is not operating 24 hours a day, the cost per megawatt is higher than other forms of energy.

  • A sunny climate, with as many cloud-free days as possible, is necessary for maximum efficiency and effectiveness. These power plants, which already have limited working hours, can only be located in desert regions.

  • Expensive transmission lines need to be run a long distance to these hot, remote regions since cheap land is located far from urban centers where the power will be consumed.

  • For these plants to be economically viable, large tracts of lands must be covered with photovoltaic or reflective mirrors. Small-scale generators do not make efficient use of land, equipment or transmission lines to make them worthwhile for individual household installation.

How To Get Involved

Obviously, a homeowner cannot construct their own solar farm to power their house. However, if you live in an arid climate, contact your power company to see if you can participate in any "green energy" initiatives they may have. The specific electrons that arrive at your home may or may not originate from the solar power farms, but your participation will help contribute to investing in solar power and to subsidize the construction of clean-power, zero-emission power generators.