Photo: Solar concentrator photovoltaic plant with a capacity of 1 kW, established in the Physico-Technical Institute. Ioffe
Solar panels are becoming more popular in the home, and the photovoltaic conversion of solar energy today is one of the most promising sectors of the renewable energy sector. Developed in the middle of the last century, American scientists G. Pearson, C. Fuller, D. Chapin solar panels originally widely used in spacecraft, and is currently widely used for domestic purposes. For example, in Germany in 2009-2010, the total capacity of installed residential solar panels was 11 GW.
However, they are still not widely available due to the high cost: the basic element of the battery — an expensive single-crystal silicon, due to which the price of a kilowatt-hour of electricity will be higher than that obtained from other sources. The solution — to improve the efficiency of solar cells and reducing their cost. Such tasks set itself the scientific staff of the laboratory of photovoltaic cells from the Physico-Technical Institute. Ioffe (PTI) led by Vyacheslav Andreev. Projects "Photovoltaic solar energy conversion" and "design and creation of off-grid solar power plants with the splitting of the solar spectrum, tracking the sun and energy storage" of these researchers supported under the Federal Target Program "Research and development", and the theme of "Development of heterostructure solar cells and photovoltaic installations "- Federal Target Program" Research and scientific-pedagogical personnel of innovative Russia ".
Nanoheterostructural efficiency cascade solar cells developed by the staff of the Institute, is 36 percent, which is two to three times higher than that of batteries that are based on silicon. Increased efficiency in such phototransformator achieved by dividing the solar light spectrum at several intervals and more efficient conversion of the photon energy in each of them. Photoconverters three stages consist of three photoactive regions consisting of three semiconductor wafers based alloys of chemical elements — GaInP, Ga (In) As and Ge. These semiconductors are converted into energy, respectively, shortwave, medium wave and infrared part of the spectrum. With more stages may increase the efficiency from 36 to 45-50 percent, but the production of such multi-stage elements are much more complicated.
Solar cell modules, developed by scientists from the Ioffe Institute, consisting of the above-described solar cells, which are located on the heat-removing substrates for focal lengths from mini-lenses that provide a thousand-fold concentration of solar radiation. This technique not only reduces the active surface area of solar cells, but their cost.
In developed by scientists battery modules are staggered on the electro-mechanical tracking system, equipped with a position sensor of the sun. This allows them a constant orientation to the sun and the best collection of sunlight in comparison with stationary batteries, to reduce wind loads. On its own power supply installation consumes just 0.1 per cent of the energy generated.
For comparison, according to calculations of scientists, a kilogram of semiconductors used in the creation of solar panels, in 25 years will produce as much energy as you can get when you use five thousand tons of oil. This will reduce the cost per watt of power these power plants up to two dollars, which is 1.5 times lower than the current world prices.
The project on the production of such power plants was introduced in the Civil Code "Nanotechnologies", has passed all examinations and has been approved by the supervisory board. With the support of "RUSNANO" in Stavropol will be launched production of solar installations, invented the PTI.
Author: Oleg Fairy