How is solar power used to make electricity?
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Answer:
There are a couple of different ways that solar power can generate electricity. The most common way for home applications is the photovoltaic effect. This technology is also used for large centralized power plants as well.
A solar cell absorbs photons (light). In order to absorb the energy of the photon the solar cell has to store that energy somehow. The way that happens is that electrons in the solar cell are boosted from a trapped state to a free state. You can think of this as like a marble in a hole on a sheet of wood. The marble plays the role of a trapped electron. If the marble is puffed hard by a blast of air (a photon) it can be popped out of the hole where it can now roll around freely. A similar thing happens to electrons when they absorb a photon in a solar cell.
The free electrons are collected by wires attached to the cell and can then be conducted away to and used to drive an electric load. Each electron has a voltage of about 0.7 volts. If solar cells are stacked in series that voltage can be built up to any level you want. In my home system my solar cells operate at about 400 volts DC. My inverter changes that to two phase 230VAC, which is connected to the grid.
The second way solar power can be used to generate electricity is to use it to generate heat. That heat is used to generate steam that is then used to drive a steam turbine. That method is very similar to the way a conventional power plant works the only important difference being the way the heat is generated. This type of system is used for very large solar power plants.
There is a closely related technology that uses a Stirling cycle generator that operates using hot air rather than steam but basically the same idea is used where heat is used to drive a generator that makes electricity. In theory a Stirling cycle generator could be more efficient than existing photovoltaic cells, but it turns out that Stirling engines are very hard to make.
imagine light photons as balls and photovoltaic cells as a large number of mini trampolines.
the balls (photons) hit the trampolines (photocells) and it creates movement (very small subtle vibrations), that movement is then transduced into electricity just like how water spun turbines do.
Scientists invented photovoltaic cells (or panels) to capture the sun's energy and turn it into electricity. They wanted to use this solar electricity to power satellites in space.
Photovoltaic cells are made up like a sandwich - two layers of silicon containing special chemicals. Sunlight is used to charge electrons in the silicon layers. The energised electrons move through the cell and flow into a wire, creating an electric current.
Solar photovoltaic power is the same technology that powers some calculators and watches. It is also used for remote telephones in some regional areas. The power of the sun is also used as a direct source in solar hot water units.
Solar power is particularly useful in remote areas (and there are a lot of these in Australia) where regular electricity supply is not available.
By generating electricity through the sun we prevent the release of greenhouse gases into the atmosphere!
simply solar panels soak up the natural warmth and energy the sun emits everyday, they are stored onto those solar cells until your home or wherever you are installing the panels needs that energy. the panels are usually wired to the houses electrical system and transfer the suns stored energy to the home. i would recomend installing such a system because it ends up paying for itself within five years of purchase. between no longer having utility bills, and being able to sell your excess power to utilities it is a win win situation.
So many really good technical answers. I'll go after the simple answer approach.
The electrons in the material of the solar panels become excited by the sun's rays. When light energy called photons hit the materials of the panel the electrons will jump around. This allows them to be collected by wires embedded in the panels, and directed out to be used as electricity. There are details like converting the solar produced electricity from direct current into alternating current and storing it in batteries for use when the sun is not shining. All this has to be worked out and is all part of the solar power project.
Solar Energy, radiation produced by nuclear fusion reactions deep in the Sun’s core (see Nuclear Energy). The Sun provides almost all the heat and light Earth receives and therefore sustains every living being.
Solar energy travels to Earth through space in discrete packets of energy called photons (see Electromagnetic Radiation). On the side of Earth facing the Sun, a square kilometer at the outer edge of our atmosphere receives 1,400 megawatts of solar power every minute, which is about the capacity of the largest electric-generating plant in Nevada. Only half of that amount, however, reaches Earth’s surface. The atmosphere and clouds absorb or scatter the other half of the incoming sunlight. The amount of light that reaches any particular point on the ground depends on the time of day, the day of the year, the amount of cloud cover, and the latitude at that point. The solar intensity varies with the time of day, peaking at solar noon and declining to a minimum at sunset. The total radiation power (1.4 kilowatts per square meter, called the solar constant) varies only slightly, about 0.2 percent every 30 years. Any substantial change would alter or end life on Earth.
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