Equipment and products that enable us to use renewable energy instead of fossil fuels and conventional electricity are highly beneficial. Examples include solar thermal systems, solar electric (photovoltaic) systems, and wind turbines. Other power generation equipment, such as fuel cells and some energy storage systems (like batteries) are included here because they help us accommodate varied energy sources so that we may eventually move beyond fossil-fuel dependence.
SunEarth, Inc., a manufacturer of solar water-heating equipment since 1978, produces flat-plate solar collectors, ICS and thermosiphon water-heating systems, and ancillary components including residential and commercial racking systems for both solar water heating and PV systems.
Solar thermal systems—also known as solar water heaters or solar domestic hot water systems when used in residential applications—provide an energy-efficient source of hot water. These systems are typically sold as complete "plug-and-play" packages that include collectors, tanks, controls and all of the necessary components.
There are a number of different solar thermal system configurations available, including:
- Direct solar thermal systems that use potable water as the heat-transfer fluid.
- Indirect systems that use propylene glycol as the heat-transfer fluid and require heat exchangers in the water tank.
- Passive systems that rely on rising hot water (or glycol) to provide circulation.
- Active systems that rely on pumps and controls for circulation.
Most cold-climate systems are indirect, active systems that use flat-plate or evacuated-tube collectors. In warm climates, direct, flat-plate collectors are common, as are inexpensive integral-collector storage (ICS), or “batch” systems, that contain both the collector and water storage.
GreenSpec lists residential and light commercial solar thermal systems certified by the Solar Rating and Certification Corporation (SRCC) to its OG-300 standards. OG-300 certified systems are tested based on collectors (certified to OG-100); storage tanks; pumps, controls, and other components; and backup water heater. OG-300 is required for a solar thermal system to qualify for a federal Residential Renewable Energy Tax Credits and to be listed as an Energy Star-qualified system.
GreenSpec lists residential systems certified to SRCC OG-300 and high-temperature commercial systems that incorporate SRCC OG-100-certified collectors.
Flat-plate solar collectors are available as glazed and unglazed units. Used for water and space heating, glazed units are insulated, sealed boxes that contain an absorber plate and glass or plastic cover. The dark-colored absorber captures solar energy and a heat-transfer fluid carries it to a storage tank.
Unglazed flat-plate collectors are made from dark-colored materials that have heat-transfer fluid running through them. Used primarily for heating pools, unglazed systems are usually less expensive and less efficient than glazed systems, and generate lower-temperature water.
GreenSpec lists innovative flat-plate collectors that are certified by Solar Rating and Certification Corporation (SRCC) to its OG-100 standards.
GreenSpec lists inverters that convert the direct-current (DC) power produced by renewable energy systems into alternating-current (AC) power needed for most conventional appliances, and for feeding site-generated electricity into the power grid.
GreenSpec also lists power-conditioning equipment, controllers, batteries, and mounting equipment, as well as tracking systems that follow the path of the sun to maximize the amount of light hitting photovoltaic collectors.
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