There are several different types of generation systems that are easily available and environmentally sound. Read below for more information about each type.

Wind

The wind turns a propeller connected to a generator in this renewable technology system. A direct current wind generator will provide its energy to direct current loads. Alternating current for refrigerators, computers, TV, etc. would have to be provided by an inverter. If the wind turbine generator produces 60 cycle alternating current, the generator could serve AC loads directly.

Wind energy experts recommend placing an 80 to 120 foot high residential wind turbine on no less than one acre of land. Smaller lots generally are not acceptable for safety and noise reasons.

The economics of a 5 to 10 kw residential system are sensitive to the average wind speed and the cost of electricity. As a general rule, an economical system requires an average wind speed of at least 10 MPH at the turbine’s location.

Solar Photovoltaic Panels

Solar photovoltaic panels (PV) generate direct current electricity. These solar cells consist of positive and negative layers on a silicon wafer. Sunlight striking the panels is absorbed, freeing electrons in the silicon crystal. Electrons activated by the sunlight move through the crystal and out to the load or battery. This type of electric generation is typically 10 to 15 percent efficient; meaning 10 to 15 percent of the energy striking the panels is converted to electricity. Research continues to increase this efficiency.

Cost of a PV system depends largely on the application. Systems containing 100 watts or more
generally cost between $10 and $20 per watt. Smaller systems are more expensive on a per watt basis.

The cost of the panels is usually one-third to one-half of the total system cost. Each watt of panel typically produces between two and six watt-hours of energy a day depending on the season and location. Solar panels can generate electricity in cloudy weather, although their output is diminished.

Energy produced on an overcast day might be as little as five to ten percent of the amount generated on a bright, sunny day.

Fuel Cell

Fuel cells are similar to batteries in that they produce electricity using an electrochemical reaction. Unlike a battery, which must be recharged, a fuel cell produces electricity continuously when supplied by a fossil fuel–usually natural gas, propane, methane, or bio-mass. These units are available commercially in the 250-kw size. Smaller residential units are also being produced and field-tested at this time.

The National Aeronautics and Space Administration (NASA) first used fuel cells to provide
electricity on space missions. Currently, 250-kw applications are found in hospitals, computer facilities and industrial firms.

A fuel cell has two major sections: the reformer and the stack. Hydrogen is stripped from the fossil fuel in the reformer. In the stack section, electricity is produced from the hydrogen. The type of reformer determines the type of fossil fuel that can be used.

While the 250-kw fuel cell can use natural gas, propane or bio-mass, optimum electrical performance is obtained with natural gas. Using propane or bio-mass will reduce the kw output of the nominally rated 250-kw unit. Others use methane as its energy source. Fuel cell size, equipment costs and maintenance requirements, as well as fuel quantity needed, are a few of the factors that determine the best fossil fuel to use in the fuel cell.

This equipment produces clean and quiet energy. This cogenerator is so clean that it enjoys a
blanket exemption from air quality standards in Southern California, which has the strictest air quality standards in the country.

Micro-turbines

Micro-turbines – like their larger counterparts, the combustion turbines – use jet engine technology to produce electricity. The simplest combustion turbine consists of three components: a compressor, a combustion chamber and a turbine.

Air is compressed in the compressor. This high temperature and high pressure air moves to the
combustion chamber where fuel is injected and the mixture is ignited. In the turbine section, this very hot mixture expands, turning the turbine shaft that is connected to the generator.

This equipment is designed and operated to produce 60-cycle alternating current and can operate on multiple fuel sources, including natural gas propane and diesel. Micro-turbines can produce electricity efficiently and cost-effectively, while emitting very low levels of pollutants. The hot exhaust can be used for space and water heating.