When experts talk about future solar cells, they usually talk about new exotic materials and physical phenomena. But in the short term to an unprecedented result can cause a more simple method of layered stacking in the same module several different and well known semiconductor materials, each tuned to their own wavelengths.
This technology does not require radical scientific solutions and can be implemented in a relatively short period, but provides a similarly effective collection of solar energy as the most advanced design work in the beginning.
Startup Semprius from North Carolina argues that the effectiveness of the method developed by them, can reach 50%, while today's commercial solar panels collect no more than a quarter of the energy of the incident sunlight.
Semprius has come up with three innovations: a cheap and fast method of layered stacking of the cells, their electrical connections and a new kind of glue that securely binds together the elements of the multilayer structure.
In the module, Semprius uses tiny solar cells, each measuring less than a millimeter. The company claims that this approach reduces cooling costs and improves overall efficiency.
Usually the stack of semiconductors building up successive layers. The difficulty is that in this way can not be combined with any semiconductors, which interfere with the peculiarities of their crystal structure.
Semprius builds up crystals of semiconductors in the usual way, but selects the appropriate combinations, resulting in new elements capture much more sunlight.
The company has demonstrated cells made of three semiconductor materials stacked on top of the fourth, which previously combine other semiconductors failed. Researchers Semprius in 2014 have created two option modules from a variety of materials with an efficiency of 43.9 and 44.1%.
In addition, the new technology is cheap and simple, it allows you to reuse the expensive crystalline wafers for the creation on their basis mnogoprokhodnyj solar panels.
The company plans for the next 3-5 years as Vice-President of Semprius Scott burrows (Scott Burroughs), combining in one device a total of 5-6 semiconductors to achieve the efficiency of transformation more than 50%.
The catch, as usual, is price. A new cell will cost more traditional, at least as long as technology has not become widespread.
According to the chief researcher of the National renewable energy laboratory (National Renewable Energy Laboratory) Sarah Kurtz (Kurtz Sarah) as the introduction of new technology will be beneficial. With an annual energy production of 80-100 MW, cells with 50% efficiency will allow to obtain electricity with the cost of only 5 cents per kilowatt-hour.
According to estimates from the energy information Administration (US Energy Information Administration) cost of new energy power plants on natural gas is 6.4 cents per kilowatt-hour.