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Information about Active Solar

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Solar trackers may be driven by active or passive solar technology


Active solar technologies are employed to convert solar energy into usable heat, cause air-movement for ventilation or cooling, or store heat for future use. Active solar uses electrical or mechanical equipment, such as pumps and fans, to increase the usable heat in a system. Solar energy collection and utilization systems that do not use external energy, like a solar chimney, are classified as passive solar technologies.

Solar hot water systems, except those based on the thermosiphon, use pumps or fans to circulate water, an anti-freeze mixture, or air through solar collectors, and are therefore classified under active solar technology. The solar collectors can be nonconcentrating or 'flat-plate', or of various concentrating designs. Most solar-thermal collectors have fixed mounting, but can have a higher performance if they track the path of the sun through the sky. Solar trackers, used to orient photovoltaic arrays, may be driven by either passive or active technology.

Because passive solar systems require no additional energy to operate and therefore have zero operating costs, emit no greenhouse gasses in operation, and can have low maintenance costs, passive solar technologies should be given full consideration.

Solar technology comparison

Active solar-thermal systems, via small pumps or fans, can have significantly higher solar savings fractions than passive solar technologies due to greatly-enhanced heat transfer and transport. An interesting hybrid approach is to use photovoltaics to power pumps or fans. A computer analysis, using thermodynamics and heat transfer software, can be used to compare the performance of various active and passive solar thermal strategies

Example

An experimental house built to active solar principles was built in 2004 in county Cork, Ireland. The house, which was monitored throughout 2005 using sensors, is apparently achieving a net energy consumption for space heating and hot water along with electricity to power a heat pump of less than 9kWh/m2/a.[1]

See also

Notes



Solar energy is energy from the sun. It supports life on Earth and drives the Earth's weather. Solar energy predominantly arrives in the form of infrared, visible and ultraviolet light, and is either returned back to space or is absorbed.
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solar chimney — often referred to as a thermal chimney — is a way of improving the natural ventilation of buildings by using convection of air heated by passive solar energy.
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Passive solar technologies convert sunlight into usable heat, cause air-movement for ventilation or cooling, or store heat for future use, without the assistance of other energy sources.
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Solar hot water refers to water heated by solar energy. Solar heating systems are generally composed of solar thermal collectors, a fluid system to move the heat from the collector to its point of usage, and a reservoir or tank for heat storage and subsequent use.
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Thermosiphon (alt. thermosyphon) refers to a method of passive heat exchange based on natural convection which circulates liquid in a vertical closed-loop circuit without requiring a conventional pump.
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solar hot water panel is a solar water heater that uses the sun's energy to heat a fluid, which is used to transfer the heat to a heat storage vessel. In the home, for example, potable water would be heated and then stored in a hot water tank.
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solar tracker is a device for orienting a solar photovoltaic panel or concentrating solar reflector or lens toward the sun. Concentrators, especially in solar cell applications, require a high degree of accuracy to ensure that the concentrated sunlight is directed precisely to the
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photovoltaic array is a linked collection of photovoltaic modules, which are in turn made of multiple interconnected solar cells. The cells convert solar energy into direct current electricity via the photovoltaic effect.
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Greenhouse gases are components of the atmosphere that contribute to the greenhouse effect. Without the greenhouse effect the Earth would be uninhabitable;[1] in its absence, the mean temperature of the earth would be about -19 °C (-2 °F, 254 K) rather than the present
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In discussing solar energy, the solar savings fraction or solar fraction (f) is the amount of energy provided via the solar technology divided by the total energy required.

The solar savings fraction thus is zero for no solar energy utilization, to 1.
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Passive solar technologies convert sunlight into usable heat, cause air-movement for ventilation or cooling, or store heat for future use, without the assistance of other energy sources.
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Thermodynamics (from the Greek θερμη, therme, meaning "heat" and δυναμις, dynamis, meaning "power") is a branch of physics that studies the effects of changes in temperature, pressure, and volume on
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In thermal physics, heat transfer is the passage of thermal energy from a hot to a cold body. When a physical body, e.g. an object or fluid, is at a different temperature than its surroundings or another body, transfer of thermal energy
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An autonomous building is a building designed to be operated independently from infrastructural support services such as the electric power grid, municipal water systems, sewage treatment systems, storm drains, communication services, and in some cases public roads.
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An architectural engineer applies the skills of many engineering disciplines to the design, construction, operation, maintenance, and renovation of buildings while paying attention to their impacts on the surrounding environment.
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Passive solar technologies convert sunlight into usable heat, cause air-movement for ventilation or cooling, or store heat for future use, without the assistance of other energy sources.
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Renewable energy utilizes natural resources such as sunlight, wind, tides and geothermal heat, which are naturally replenished. Renewable energy technologies range from solar power, wind power, and hydroelectricity to biomass and biofuels for transportation.
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Solar energy is energy from the sun. It supports life on Earth and drives the Earth's weather. Solar energy predominantly arrives in the form of infrared, visible and ultraviolet light, and is either returned back to space or is absorbed.
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Sustainability is a characteristic of a process or state that can be maintained at a certain level indefinitely. The term, in its environmental usage, refers to the potential longevity of vital human ecological support systems, such as the planet's climatic system, systems of
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Energy development is the ongoing effort to provide sustainable energy resources through knowledge, skills, and constructions. When energy from primary energy sources and converting them into more convenient secondary energy forms, such as electrical energy and cleaner fuel, both
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Future energy development, providing for the world's future energy needs, currently faces great challenges. These include an increasing world population, demands for higher standards of living, a need for less pollution, a need to avert global warming, and a possible end to fossil
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The 2000-watt society is a vision, originated by the Swiss Federal Institute of Technology at the end of 1998, in which each person in the developed world would cut their rate of energy use to an average of no more than 2,000 watts (i.e.
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Hubbert peak theory posits that for any given geographical area, from an individual oil field to the planet as a whole, the rate of petroleum production tends to follow a bell-shaped curve.
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peak oil is the point or timeframe at which the maximum global petroleum production rate is reached. After this timeframe, the rate of production will enter terminal decline. According to the Hubbert model, the production rate will follow a roughly symmetrical bell-shaped curve.
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Transport or transportation is the movement of people and goods from one place to another. The term is derived from the Latin trans ("across") and portare ("to carry").
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