![]() ![]() This method of collection has an efficiency of 20-80% depending on the design of the collector. These carrier fluids are typically heated to between 66 and 93☌. The hot water can either be drawn directly from the storage tank or passed through pipes in floors and ceilings to heat homes or business premises as space heating. Flat plate collectors are used for solar water or house heating, with the heated water being gathered on sunny days and stored in insulated tanks so it can be used at night or on cloudy days. Carrier fluids such as water flow past the back of the plate, warming up so the thermal energy can be used directly or stored as a different medium. These plates, which can have surface areas of around 40 square metres, heat up as sunlight falls upon them. One of the more common methods is the use of large flat plate collectors, which are commonly made of blackened metal plate covered in sheets of glass. There are several techniques that are used to capture solar energy and convert it into thermal energy. One method for this is to focus the heat upon blackened pipes, through which water is passed, to warm it up. This focusing can heat a target to 2,000 ☌ (3,600 ☏) or more, operating a boiler that creates steam, which turns turbines and powers an electricity generator. Most modern photovoltaic cells are around 15-22% energy efficient (although improvements are being made), which mean that large assemblies may be required to generate moderate amounts of power.Ĭommon smaller scale uses of solar cells include providing a power source for pocket calculators and watches, while homeowners and businesses use larger arrays to replace or augment their conventional electric supplies and solar power plants can offer even greater levels of electricity generation by concentrating or focusing the light with aligned mirrors or lenses. Creating solar panel arrays from large numbers of solar cells allows for thousands of kilowatts of energy to be generated. This supplies a small amount power to the load, with each photovoltaic cell producing around two watts. The photovoltaic effect frees electrons, which flow through an external circuit as the semiconductors present a natural difference in electric potential (voltage). ![]() When sunlight hits a solar cell, a small electric voltage is generated as the photovoltaic effect takes place between a metal and semiconductor like silicon, or two different semiconductors. Electricity GenerationĮlectricity can be generated from sunlight using solar cells (also called photovoltaic cells). When harnessed, solar radiation can be converted into electrical energy with solar panels, for example, or converted into thermal (heat) energy, which is easier to achieve. Exploiting this renewable resource can be difficult however, with collection, conversion and storage still being quite costly. Although much of the solar energy is lost as it travels to the surface of the Earth, this energy still equals around 200,000 times the daily total electricity generating capacity of the world. As a result, the sunlight that reaches the ground is around 50% visible light and 45% infrared radiation with the rest being made up of small amounts of ultraviolet and other types of electromagnetic radiation. More of this sunlight is lost in the Earth’s atmosphere and due to clouds, which between them scatter as much as 54% of the incoming light. Sunlight is the largest energy source to reach the Earth but, despite this, the intensity of the energy that reaches the Earth’s surface is relatively low due to the radial spreading of solar radiation as it travels from the distant Sun. National Structural Integrity Research Centre.Structural Integrity Research Foundation.
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