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im looking to get solar panels. what type should i get? who is the best company to buy from? do i need to have someone come to my house and evaluate it? and if it make any difference i live in southern california in tulare county
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This may help. I dont want to tell you where to go so I have provided you with enough info to make the decision on your own.
Types of technologies
Many technologies have been developed to make use of solar radiation. Some of these technologies make direct use of the solar energy (e.g. to provide light, heat, etc.), while others produce electricity.
Solar design in architecture
Main article: Passive solar building design
Solar design in architecture involves the use of appropriate solar technologies to maintain a building’s environment at a comfortable temperature through the sun's daily and annual cycles. It may do this by storing solar energy as heat in the walls of a building, which then acts to heat the building at night. Another approach is to keep the interior cool during a hot day by designing in natural convection through the building’s interior.
Solar heating systems
Main articles: Solar hot water and Solar combisystem
Solar hot water systems use sunlight to heat water. They may be used to heat domestic hot water, for space heating or to heat swimming pools. These systems are composed of solar thermal collectors, a storage tank and a circulation loop.[8] The three basic classifications of solar water heaters are:
Batch systems which consist of a tank that is directly heated by sunlight. These are the oldest and simplest solar water heater designs, however; the exposed tank can be vulnerable to cooldown.[9]
Active systems which use pumps to circulate water or a heat transfer fluid.
Passive systems which circulate water or a heat transfer fluid by natural circulation. These are also called thermosiphon systems.
A Trombe wall is a passive solar heating and ventilation system consisting of an air channel sandwiched between a window and a sun-facing wall. Sunlight heats the air space during the day causing natural circulation through vents at the top and bottom of the wall and storing heat in the thermal mass. During the evening the Trombe wall radiates stored heat.[10]
A transpired collector is an active solar heating and ventilation system consisting of a perforated sun-facing wall which acts as a solar thermal collector. The collector pre-heats air as it is drawn into the building's ventilation system through the perforations. These systems are inexpensive and commercial models have achieved efficiencies above 70%. Most systems pay for themselves within 4-8 years.[11]
Solar lighting
Main articles: Daylighting and Light tube
Solar lighting or daylighting is the use of natural light to provide illumination. Daylighting directly offsets energy use in electric lighting systems and indirectly offsets energy use through a reduction in cooling load.[14] Although difficult to quantify, the use of natural light also offers physiological and psychological benefits.
Daylighting features include building orientation, window orientation, exterior shading, sawtooth roofs, clerestory windows, light shelves, skylights and light tubes.[15] These features may be incorporated in existing structures but are most effective when integrated in a solar design package which accounts for factors such as glare, heat gain, heat loss and time-of-use. Architectural trends increasingly recognize daylighting as a cornerstone of sustainable design.
Daylight saving time (DST) can be seen as a method of utilising solar energy by matching available sunlight to the hours of the day in which it is most useful. DST energy savings have been estimated to reduce total electricity use in California by 0.5% (3400 MWh) and peak electricity use by 3% (1000 MW).[16] However, there is some question whether these estimates are valid. In 2000 when parts of Australia began DST in late winter, overall electricity consumption did not decrease, but the peak load increased.[17]
Solar pond
A solar pond is simply a pool of water which collects and stores solar energy. It contains layers of salt solutions with increasing concentration (and therefore density) to a certain depth, below which the solution has a uniform high salt concentration. It is a relatively low-tech, low-cost approach to harvesting solar energy. The principle is to fill a pond with 3 layers of water:
A top layer with a low salt content.
An intermediate insulating layer with a salt gradient, which sets up a density gradient that prevents heat exchange by natural convection in the water.
A bottom layer with a high salt content which reaches a temperature approaching 90 degrees Celsius.
The layers have different densities due to their different salt content, and this prevents the development of convection currents which would otherwise transfer the heat to the surface and then to the air above. The heat trapped in the salty bottom layer can be used for heating of buildings, industrial processes, generating electricity or other purposes. One such system is in use at Bhuj, Gujarat, India[26] and another at the University of Texas El Paso.[27]
Solar chemical
Solar chemical is any process that harnesses solar energy by absorbing sunlight in a chemical reaction in a way similar to photosynthesis in plants but without using living organisms. No large-scale systems have as yet been constructed.
Another chemical (but not photochemical) approach has been to use conventional solar thermal collectors to drive chemical dissociation reactions. Ammonia can be separated into nitrogen and hydrogen at high temperature and with the aid of a catalyst, stored indefinitely, then recombined later to release the heat stored. A prototype system was constructed at the Australian National University[28].
A promising approach is to use focused sunlight to provide the energy needed to split water into its constituent hydrogen and oxygen in the presence of a metallic catalyst such as zinc.[29]
While metals, such as zinc, have been shown to drive photoelectrolysis of water, more research has focused on semiconductors. Further research has examined transition metal compounds, in particular titanium, niobium and tantalum oxides.[30]
Unfortunately, these materials exhibit very low efficiencies, because they require ultraviolet light to drive the photoelectrolysis of water. Current materials also require an electrical voltage bias for the hydrogen and oxygen gas to evolve from the surface, another disadvantage. Current research is focusing on the development of materials capable of the same water splitting reaction using lower energy visible light.
It is also possible to use solar energy to drive industrial chemical processes without a requirement for fossil fuel.
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The type depends upon what you want the solar panels to do. Generate electricity ? Heat gain? Makes a big difference. You should probably get a contractor who specialises in solar panels out to at least start your education on this subject or you could throw a lot of money away on something you don't really need or want.
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The only people who could tell you are the manufacturers and the installers. Any of them are likely to tell you theirs are the best. Mine are Siemens and about five years old. I have had no trouble with them.
There are many things to consider when contemplating having a solar system installed. You can learn a lot by clicking on SOLAR PANELS at the upper right of this page.
