Solar Heating

Solar power is one of the cleanest sources of energy available and one whose acceptance and development is constantly growing. Currently, solar power is available to home owners in various ways, mainly through photovoltaic panels (PV) and solar heating. A solar heating system is designed to reduce the need for conventional water heating by about two thirds, according to an estimate by the U.S. Department of Energy. Therefore it impacts positively on our dependency on fossil fuel and conventional electricity and mitigates a household�s impact on the environment.

Usually, solar heating systems have two parts: a solar collector and a storage tank. The collector heats the water and the heated water is held in the storage tank, ready for use. A conventional system co-exists with the solar system in order to provide any additional heating, when necessary. There are active and passive solar heating systems. The former use electric pumps and controllers to circulate water. The latter rely on gravity and water�s natural tendency to circulate when heated. These are more reliable (due to the absence of electrical components), easy to maintain and they tend to last longer.

Besides helping the environment, solar heating systems can also provide a source of financial savings. The U.S. Energy Policy Act implemented a 30% tax credit for consumers who install solar water heating systems. To quality for this tax break, the systems must be certified by the Department of Energy's non-profit partner, the Solar Rating & Certification Corporation (SRCC). However, in Florida and Hawaii residents can use their area�s own certification programs. Those who would like to benefit from solar heating without installing any equipment, passive solar technology should be of help. It is a concept that informs the design of a building, which will be planned to collect, store and distribute solar energy as heat in the winter and mitigate solar heat in the summer. In general, no mechanical and electrical designs, such as pumps and fans, are required.

According to Energy Savers, a governmental agency dedicated to energy efficiency, there are five elements that constitute a complete passive solar home design to generate solar heating. These are aperture (the entry point of solar light), absorber (the hard, dark surface of the storage element), thermal mass (the materials that retain or store the heat produced by sunlight, distribution (how solar heat circulates from the collection and storage points to different areas of the house) and control (elements to shade the aperture area during summer months, such as roof overhangs). The latter�s purpose is to ensure the house will be comfortable during summer as well.

Passive solar design can range from total reliance on solar power or just partial use of this type of renewable energy to produce solar heat. That will depend on design and geographical location. Wind patterns, topography, vegetation and amount of sunshine in the area play a key role in passive solar design and the performance of the building. Passive solar design principles can be applied to new constructions or adapted to existing buildings, which will need to be retrofitted.