Resources | Renewable energy basics

Renewable energy refers to energy generated from natural resources, such as biomass, geothermal, solar, water (hydropower) and wind.  Renewable energy can generate electricity or provide a direct source of heat (thermal) energy for  hot water tanks, pools or homes..  In 2007,  8% of electricity in the US was generated by renewable energy sources.

The use of renewable energy promotes sustainable living and energy independence while reducing carbon emissions and energy costs.

Renewable energy systems for residential and commercial use include a wide range of options that can provide primary or supplementary sources of energy. These options may include installing one or more of the following configurations:

•             Biomass systems use wood, plants, or bio-waste as a fuel to generate electricity, thermal energy, or both.  Some bio-fuels are used for power transportation, like cars.

•             Geothermal systems use the earth’s heat (low-temperature) to regulate temperatures, warming a space during cold weather or cooling a space during hot weather.  Medium-temperature geothermal systems generally provide heat.  High-temperature systems are a good choice for utility scale applications, such as generating electricity.

•             Hydropower systems use water’s kinetic energy to generate electricity with turbines.  These small turbines are similar to those found at hydro power plants.

•             Solar systems use the sun’s light energy to generate electricity (photovoltaic) or capture the sun’s thermal energy to heat air, water, or other fluids.  Some utility scale application solar thermal systems are designed to power electric generators.

•             Wind systems use the wind’s kinetic energy to generate electricity with turbines.  These turbines typically consist of three blades ranging from two to sixty feet in length.

Renewable energy systems that provide 100% of the energy needed by a household or other applications are called stand-alone, or off-grid, systems. If you plan to generate less than 100% of your household energy power using renewable energy, you can stay connected to the utility power, or install a generator, for the rest. Renewable energy systems that also connect to utility power are grid-tied or grid-interactive systems. One drawback of a grid-interactive system includes power loss when the utility goes down, even when the renewable energy system is operational (due to safety design).  For this reason, you might choose a variant of grid-interactive systems called grid-interactive with battery backup.  In grid-interactive with battery backup systems, a bank of batteries, attached to the system, act as a backup power source when utility power is not available. These systems are typically more complex in design, more expensive and less efficient than pure grid-interactive systems.

Successful selection of a renewable energy system depends on your goal and location. We can help you choose the system that best suits your budget and the renewable energy sources available in your area.  If you plan to generate 100% of your household energy from renewable energy, you may require more than one renewable energy source, depending on your location.  For example, if you live in a warm location with sufficient sunlight and adequate rooftop space, a solar array may meet your needs.  However, if you live in a location that has moderate sunlight, you may need to install a “hybrid” system that utilizes both solar and wind energy.