Residential Solar energy is a hot topic in the sustainable building industry. The sun as a renewable and free source of energy can be used to generate electricity with solar photovoltaic (PV) panels or used to heat hot water with a Solar Thermal System. Solar PV and Thermal can be combined to work together or separately – and can also be combined to work with our geothermal systems.
Solar Thermal Hot Water Systems
According to the US Department of Energy, a solar thermal water heater can drop your water heating bill an average of 50-80%. Most solar hot water systems require back-up water heating such as electricity or gas for periods of low sunlight, but special system design can drastically increase the efficiency of these systems. Integration of solar hot water with radiant heating and a geo-exchange (geothermal heat pump) system can provide heat and hot water for the entire home, year round.
The components of a solar water heating system typically consist of a solar collector, one or more hot water storage tanks, flow pumps and a back-up energy source. The size of the system depends on the hot water requirements and geographic location of the home. For additional and more detailed information on Solar thermal / solar hot water systems refer to our renewable energy development partner – Energy Environmental Corporation: www.energyhomes.org
Solar Photovoltaic (PV) Panels
Solar cells or photovoltaics (PV) turn sunlight into electricity. Solar PV panels provide a clean alternative form of power to homes and buildings. The energy savings of solar panels depend on the number and size of panels, the energy needs of the home and solar intensity of the geographic location.
Solar PV and Solar Thermal – Efficiency Considerations
Current technologies and materials limit Solar PV efficiency. Currently, solar photovoltaic cells become less efficient as they get hotter, a decline that can be substantial on hot sunny days. Furthermore, solar PV is inefficient and some energy is ‘lost’ to the surrounding environment. However, this weakness can be overcome by combining a solar thermal system. This combination can very easily compliment a stand-alone Solar PV system’s strengths while compensating for its deficiencies.
By placing a solar thermal collector behind a solar photovoltaic (PV) array, the PV cells can be cooled. At the same time, the solar collector can harvest most of the energy that passes through the array that would otherwise be lost, recovering it for productive use. The collector transfers captured energy to a circulating medium, (fluid or air) that in turn takes it somewhere to be stored or used, such as a hot water tank, a building space, or to the ground for later retrieval by heat pump.
Combining these two solar technologies together, the solar PV cells are cooled by contact with the solar thermal collector to a more optimum operating temperature, ideally about 25°C. In providing both thermal and electrical forms of energy, this combination strategy results in a solar co-generation process. For additional detailed information on Solar PV / Solar Photovoltaic / Solar Electric systems refer to our renewable energy development partner – Energy Environmental Corporation: www.energyhomes.org
As with geothermal heating systems, solar PV and Solar thermal systems all qualify for 30% Federal Tax Credits. Determining which technologies to employ or in combination, should be approached with careful engineering and set energy savings objectives.
In summary, Platinum Homes, has systematically evaluated the latest technologies of solar PV, solar thermal, and geothermal exchange systems. Our focus is to deploy these ever changing technologies in a way that efficiently and economically makes sense for use by our customers.