The path to purification

Scientists have developed a self-cleaning solar cells to solve the problem of dust, which inhibits the development of solar energy.

Boring dust? . This issue is highly relevant for large solar power plants. But scientists from the American Chemical Society proposed exit - self-cleaning solar cells based on technologies developed for space missions.

The basis of self-cleaning technology - a thin transparent film of electro, which is applied to glass or plastic cover solar panels. If the dust concentration reaches a critical level, special sensors activate the film, which with the help of electrical discharge repels dust. Images of ' wave' of dust, which pushes the dirt to the edges of the panel and throws them on the ground. Within 2 minutes, removed about 90 % of the dust. To operate the system requires very little power. This technology was originally developed in conjunction with NASA for use in flight to the moon and Mars, which are known to be dusty and dry environment.

How important is this technology can be evaluated by such figures: 4 cm3 of dust on a square. m reduces energy production by 40%. Each month, for example, in Arizona, is deposited on the panel is about 4 times more dust, the Middle East, Australia and India - even more ' dusty ' regions. It is washed with water, but it is expensive, and find water in the desert is very problematic.

The current market volume of solar cells is about 24 billion dollars. In the solar energy accounts for less than 0.04% of world energy production, but if you cover the solar panels only 4% of Earth's deserts, this will be sufficient to meet all human needs for energy. Dust was a major obstacle in the construction of solar power plants in barren arid regions, but with a new self-cleaning technology, perhaps it will develop large-scale construction.

Today, for the generation of electricity from solar energy, mostly use different versions of collector generators, t. e. large mirrors that heat the coolant, which in turn spins a turbine. This is explained by the fact that the panels with equal maintenance costs are much cheaper than collectors, in fact, it's a plate of polished metal. But the self-cleaning will reduce maintenance cost of solar power panels cheap fixed to almost zero - need only 1-2 of the operator on duty. Once built, this power will be able to work 30 or more years without any major investments, generating a ' gratuitous ' and totally secure energy. In addition, the procedure of capacity increase and modernization of the elementary - you just need to install additional panels. This makes large solar power competitive and attractive for countries with large ' reserves ' of solar energy.

Currently a leader in solar energy are the United States. Only this year signed a contract worth 700 million dollars. construction in Arizona two solar power plants with total capacity of 175 MW, they will be put into operation in 2012. A small (0.5 square meters. km) to the power of solar panels in the U.S. Air Force NELLIS AFB generates 14 MW at a cost of 100 million dollars. In the Mojave Desert solar power collector operates more than 500 MW of capacity, it takes 24 square. km at a cost of $ 2 billion. For comparison, planned to build a nuclear power plant in Armenia will be worth five billion dollars. , To produce 1,000 MW and built 5-7 years. As you can see if there is sufficient space and the amount of sunlight, solar energy is becoming more attractive and could easily replace some outdated and dangerous technology of electricity generation.

source.