solar panels Coventry | solar panel installers Coventry | Pv solar panels
solar panels Coventry | solar panel installers Coventry | Pv solar panels
A solar panel simply put is a collection of solar cells. They work together to supply electricity for various uses. A single cell does not have the capacity for generating a lot of electricity so multiple cells are connected together to increase the capacity, how many cells depends on the amount of electricity required. The more light available to the solar panels the greater the amount of electricity they can supply.
Solar panels are designed to convert light into electricity. The process of extracting electricity from light is called Photovoltaic (PV) and the PV process converts solar energy directly into electricity.
A PV cell, also known as a self-generating barrier layer cell is a PV detector that converts radiant flux straight into electrical current. It consists of a thin silver film on a semiconductor layer deposited on an iron substrate.
The development of solar energy dates back more than 100 years, to the middle of the industrial revolution. There were a number of groundbreaking solar power plants constructed to produce steam from the heat of the sun, which was used to drive the machinery. At the same time, Henri Becquerel discovered the photovoltaic effect that is the production of electricity directly from the sun. Becquerel’s research was investigated and extended by several sientists among them was Werner Siemens. Photovoltaic power remained a novelty for many years, since it was very inefficient at turning sunlight into electricity.
This technology is used in spacecraft by NASSA as it’s simplicity provides stability because it has no moving parts and does not require refueling so they are reliable, long-lasting and do not require regular maintenance. The solar panels are usually designed to so that the cells face the sun at all times to maximise the benefit of the light available.
There are no harmful emissions from PV equipment and its operations are virtually noise free, which makes it environmentally superior to alternative forms of generating electricity.
The practical use of solar power for remote homes is gaining momentum. In the past people who wanted to live in remote areas had to pay a high price for power to be connected to their houses but with solar technology they be virtually self-sufficient and as a bonus they have no worries about blackouts. Most home appliances run on alternating current (AC) but with an inverter, which converts direct current (DC) power from the solar cells to alternating current (AC), a solar home can operate very much like a home connected to a power line. Even a phone box in the middle of nowhere can be powered by solar power from solar panels eliminating the need for underground cables.
RV systems can now be used to power a wide variety of our every day requirements from watches to hot water. The development of a commercial vehicle that can, at least in part, derive its power from the sun will solve a lot of problems such as pollution emissions from the burning of fossil fuel and the cost of using a finite resource will be greatly reduced. The more solar power we use the greater the relief on current powering systems and can help avoid creating more nuclear reactors that create horrific pollution problem with what to do with contaminated waste.
Ongoing research has yielded different and ever more efficient and versatile forms of the semiconductor wafers, such as gallium arsenide, that go to form solar cells. There are now variations that can be used in partial shade without a great loss of efficiency and forms that are more tolerant of high temperatures enabling their use in remote desert locations. Lightweight portable PV panels are now available that can be used to power communications equipment or recharge batteries in expedition environments. There are also panels with a high degree of structural integrity and these can be incorporated as part of roof fabric rather than as later additions to a structure.
Once in place, they are low-maintenance – making them ideal for remote or inaccessible locations, silent and in many cases, unobtrusive; the best place for a solar panel is in direct sunlight, away from any obstructions, and this is often out of sight on rooftops.
Until recently, generating electricity from sunlight has often been prohibitively expensive and its domestic application has usually been seen as the preserve of either the wealthy or seriously committed environmentalist. Increases in the efficiency of PV cells combined with greater governmental awareness, especially in Europe and Japan, of the merits of alternative and renewable energy sources, have lead to bold initiatives such as grants and subsidies being taken to encourage PV panel usage.
How Solar Panels Work
Photovoltaic (PV) cells are formed from a wafer of semi-conductor material and although there are now several types in production using different materials, the most common semi-conductor used is silicon.
Pure crystalline silicon is a poor electrical conductor but treat it with tiny quantities of an impurity, either phosphorous or arsenic
(a process called “doping”) and enough electrons of these materials are freed to enable a current to pass through. Electrons are negatively charged so this type of silicon is called N-Type.
Dope silicon with gallium or boron and “holes” are created in the crystalline lattice where a silicon electron has nothing to bond with. These holes can conduct electrical current and the lack of an electron creates a positive charge so this type of silicon is therefore called P-Type. Both types of silicon are modest electrical conductors, hence the name semiconductors.
Put a layer of each kind together in a wafer, such as in a PV cell, and the free electrons in the N side migrate towards the free holes on the P side. This causes a disruption to the electrical neutrality where the holes and electrons mix at the junction of the two layers. Eventually a barrier is formed preventing the electrons from crossing to the P side and an electrical field is formed, separating both sides. This electrical field acts as a diode, allowing electrons to pass from the P side to the N side, but not vice versa.
Expose the cell to light, and the energy from each photon (light particle) hitting the silicon, will liberate an electron and a corresponding hole. If this happens within range of the electric field’s influence, the electrons will be sent to the N side and the holes to the P one, resulting in yet further disruption of electrical neutrality. Apply an external pathway connecting both sides of the silicon wafer and electrons will flow back to their original P side to unite with the holes sent there by the electric field.
This flow of electrons is a current; the electrical field in the cell causes a voltage and the product of these two is power.
Several factors affect the efficiency of a solar cell. Some cells, mainly ones made from a single material, are only efficient in certain light wavelengths. Single material cells can at the very most expect to convert about 25% of the light hitting it to electrical power.
Research is ongoing into multi-junction cells combining two or more different materials in a single cell. These can have a theoretical efficiency of up to 70% but the cells are problematical in that too many layers can put the crystals under too much strain. The most efficient multi-junction cell so far has attained a 30% efficiency with just two layers. A recent encouraging discovery has found that alloys of indium gallium nitride have the potential to convert the full light spectrum to electrical power with the added bonus that they could also be very cheap to produce.
solar panels Coventry | solar panel installers Coventry | Pv solar panels
