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.
While resilience—the ability to weather natural disasters and maintain livable conditions in the aftermath of disruptive events—is mostly an issue of building design and community preparedness, certain products can help. For example, almost all heating systems require electricity to operate even if their primary fuel is oil, gas, or wood pellets; systems that allow operation even if grid electricity is not available are more resilient in the event of power outages. Rainwater harvesting, water storage, composting toilets, and waterless urinals contribute to resilience not only in drought-prone areas but also during power outages in any home dependent on well water. Solar water heating systems that can operate without utility power, and back-up power systems that are more energy-efficient than standard generators, may have this attribute.
Power Partners Solar offers a number of commercial and residential solar thermal systems using flat plate collectors. Residential systems include open- and closed-loop glycol systems for warmer and colder climates, respectively. The company’s commercial systems are custom designed using its lightweight SRCC OG-100-certified collectors. These collectors, which incorporate a dual-wall polycarbonate glazing, are available in 26 trim colors and come with a limited ten-year warranty. Complete residential systems have a one-year warranty.
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.
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.
EAc1: Optimize Energy Performance
EAc1.3: Optimize Energy Performance—HVAC
EAc2: On-Site Renewable Energy
EAc2: On-site Renewable Energy
EAp2: Minimum Energy Performance
Ratings and Commentary