Thousands of years we have been using the Sun to dry clothes and food, but we recently able to apply it to generating solar energy.
The distance from the Earth to the Sun is approximately 150 million kilometers, and it's energy amazingly powerful. Simply a little part of the particular solar energy that hits the Earth (about one hundred million percent), to meet all our energy needs many times over. |
| Solar Panels |
Solar energy (solar cell) systems
Solar panels convert sunlight into electricity. Solar cells are usually often used to power calculators and watches. It's made of substrates materials similar to those used in computer chips. When these materials absorb sunlight, solar knocks electrons loose from their atoms, allowing electrons to flow through the material to produce electricity. This process is called convert light (photons) to electricity (voltage) optical effect (PV).
Solar cells are usually integrated into modules that hold about 40 cells; many of these units in photovoltaic arrays that can measure up to several meters on the side. You can download these arrays PV flat panel fixed angle facing south, or they can be attached to the tracker that follows the Sun, allowing them to capture the most sunlight over one day. Several PV arrays connected can provide enough power for household electric utilities or industrial applications can have hundreds of interconnected arrays to form one large PV system.
Solar cells use thin layers of semiconductor material only a few micrometers thick. Thin film technology has produced it possible for photovoltaic panels to double surface plates now as rooftop shingles and build interfaces or glass skylights or Atria. The version of the items like solar panels such as shingles provides the same protection and durability as regular asphalt shingles.
Some solar cells designed for working with concentrated sunlight. These cells are built into concentrating collectors that use a lens to focus sunlight on the cells. This approach has advantages and disadvantages compared to flat-plate PV arrays. The main idea is to use to tiny from the costly semiconducting PV material while collecting as much sunshine as possible. But due to the fact, the lenses must end up being pointed at the Sun, use collectors to focus exclusively on the sunniest parts of the country. Some collectors focus designed for installation on simple tracking devices, but require the most sophisticated monitoring devices, as well as reducing the use of electrical utilities, industries, and large buildings.
See also: Solar panels-Generating energy from the sun
Solar cell performance is measured regarding efficiency in converting sunlight to electricity. Only sunshine from energies will work efficiently to create electricity, and much of it reflected or absorbed by the material that forms the cell. Because of this, a typical commercial solar cell efficiency of 15% for one-sixth of the sunlight hitting the cell generates electricity. Low efficiency means that there need to be more arrays, mean higher cost. Improve the efficiency of solar cells while holding down the cost of each cell is an important goal for manufacturing PV, NREL researchers, and other United States Department of Energy (DOE) laboratories, and it offers made considerable progress. The first solar cells, built within the 1950s, was much less than 4% efficiencies.
Solar electricity
Today many power plants using fossil fuels as a source of heat to boil water. Steam from boiling water spins big turbines, which activates the generator that produces electricity. However, using a new generation of power plants, with emphasis on solar energy systems, the Sun as a source of heat. You will find three main types of concentrating solar power systems: parabolic trough, dish/engine, and power tower.Parabolic-trough systems to focus the Sun's energy through long rectangular, curved (U-shaped) mirrors. Mirrors tend towards the Sun and focusing sunlight on a pipe runs down the center of the trough. This heating oil flows through the pipes. The hot oil can be used to boil water in a conventional steam generator to produce electricity.
A dish/engine system uses a mirrored platter drive (similar to a huge satellite dishes). The dish-shaped collects and focuses the Sun's heat on a receiver, which absorbs heat and transfers it to fluids inside the engine. Heat causes the liquid to expand against a piston or turbine to produce mechanical energy. Mechanical energy is then used to run a generator or alternator to generate electricity.
Power Tower system uses a big field of mirrors to concentrate sunlight on the upper part of the tower, where the receiver sits. This particular heats molten salt flowing through the receiver. Heat is then used for salt to generate electricity through a steam generator. Molten Salt retains heat so efficiently, so they can be stored for days before being converted to electricity. That means can produce electricity on cloudy days or even several hours after sunset.
Solar hot water
The shallows of the lake are usually warmer than deep water. That's because the sunlight can heat the bottom lake in depthless areas, which in turn heats the water. It's nature's way of heating water with solar energy. The Sun can be used mainly in the same way to heat the water used in swimming pools and the buildings.Many solar water heating systems for buildings have two main parts: a solar collector and storage tank. Most commonly called flat panel collector. On the surface, it consists of a thin, flat and rectangular box with the transparent lid facing the Sun. The small pipe run through the box and carry the fluid - either water or another fluid such as antifreeze solution - to be heated. The pipes connected to the absorber plate painted black to absorb heat. Since the heat builds up within the collector, it heats the liquid passes through the tubes.
Then the hot fluid reservoir holds. Could be just the water heater has been modified, but it is usually larger and very well insulated. Other fluids used systems of water usually heat the water passes through a coil tube in the tank, filled with hot liquids.
Solar hot water systems can be either active or passive, but the most common active systems. Active systems depend on pumps for transferring fluid between collector and storage tank while passive systems depend on the gravity and the tendency for water to naturally circulate as it heats up.
Swimming pool systems are simple. The pool's filtration system pump is required to pump water through a solar collector, which is usually made of rubber or black plastic. And definitely, the pool stores the hot water.
See also: Right source of hot water for eco-friendly home
Passive Solar Heating and Daylighting
Step outside on a hot and sunny summer day, and you will feel the power of the solar heat and light. Nowadays, many buildings are designed to benefit from these natural resources through the use of passive solar heating and daylighting. The South side of a building always has more sunlight. Therefore, the buildings designed for passive solar heating usually big, south facing windows. Materials which absorb and store the sun's heat can be built in the sunlit floors and walls. The floors and walls will warm up daily and slowly release heat at night when heat is needed most. This feature is called passive solar design direct gain.Another passive solar heating design features include sunspace and Trombe walls. Sunspace (which is like a greenhouse) is built on the South side of the building. As sunlight passes through the glass or other glazings, warms the sunspace. Ventilation allows heat to circulate inside the building. On the other hand, is a very thick wall Trombe, south facing the wall, is black and made of materials that absorb a lot of heat. A pane of glass or plastic glass, installed a few inches in front of the wall, helps to keep in the heat. Wall structure heats gradually daily. Then as it cools slowly during the night, it gives off heat inside the building.
Many of the passive solar heating design as daylighting features. Daylighting is only using natural sunlight brighten the interior building. To lighten the north-facing rooms upper levels, a clerestory- a row of windows near the peak of the roof – is often used along with open floor plan inside that allows the light to bounce all over the building.
And of course, lots of daylighting and solar heating may be a trouble during the hot summer season. The good news is, there are lots of design features that help keep passive solar buildings cooler in summer. For example, you can create overhangs for shading windows when the sun is high in the summer. Sunspace could be closed off for the rest of the building. The building can be designed to use fresh air ventilation in summer.
Solar space heating and cooling process
Industrial and commercial buildings may use the same solar technologies-photovoltaic, passive heating, daylighting, and water heating— that are used for residential buildings. These non-residential buildings can use solar technologies that would not be practical for home. These technologies include ventilation air preheating, solar heating and cooling process.Many large buildings need air ventilation to maintain indoor air quality. In cold climates, you can use this heating air large amounts of energy. The solar ventilation system can preheat the air, save energy and money. This type of system usually uses collectors event, which consists of a thin metal plate, black mounted on the South-facing wall to absorb the sun's heat. Air passes through many small holes in the Panel. Space behind the perforated wall allows currents of air holes blend. Then suck the hot air out of the upper part of the space in the ventilation system.
Solar process heating systems are created to produce lots of hot water or space heating for non-residential buildings. The most system consists of solar collectors that work along with the pump and heat exchanger have one or more of the large storage tanks. Two main types of solar collectors used - an evacuated-tube collector and a parabolic-trough collector- can operate at high temperatures with high efficiency. Evacuated-tube collector shallow box filled with lots of glass and double tube walls and reflectors to heat the fluid inside the tube. The isolated vacuum between the walls of the inner tube, holding in the heat. Parabolic troughs are long, rectangular mirrors, curved (U-shaped) tends to focus sunlight on a tube, which runs down the center of the trough. This heats the fluid inside the tube.
You can also use the heat from a solar collector to cool the building. It may seem impossible to use heat to cool the building but makes more sense if you just think solar heat as an energy source. Your home air conditioner a uses a familiar source of energy, electricity, to create a cool atmosphere. Solar absorption coolers used a similar approach, along which includes complicated chemistry methods to generate cool air through solar energy. Solar energy may also be used with evaporative coolers (also called "swamp coolers") extend their usefulness for more humid climates, using another chemistry approaches called desiccant cooling.
Sources:
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Patent US4322297 - Controller and control method for a ... (n.d.). Retrieved from http://www.google.com/patents/US4322297
Solar Hot Water - Renewable Energy World. (n.d.). Retrieved from http://www.renewableenergyworld.com/solar-energy/tech/solarhotwater.html
Passive Solar Heating & Daylighting - Renewable Energy World. (n.d.). Retrieved from http://www.renewableenergyworld.com/solar-energy/tech/solarpassive.html
Harness the Power of the Sun | Department of Energy. (n.d.). Retrieved from http://energy.gov/energysaver/articles/harness-power-sun
FAQ's - Water Research Foundation. (n.d.). Retrieved from http://www.waterrf.org/knowledge/energy-management/renewable-energy/Pages/faqs.a
NREL: Learning - Solar Process Heat Basics. (n.d.). Retrieved from http://www.nrel.gov/learning/re_solar_process.html
UTPB | Solar Energy. (n.d.). Retrieved from http://www.utpb.edu/cobe/the-jan-and-ted-roden-center-for-entrepreneurship/utpb-
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