"Hi-tech sunflower" from IBM converts light into heat and electricity with an efficiency of 80%



    Three companies at once, IBM (a research unit from Zurich), Airlight Energy and Dsolar (a subsidiary of Airlight), presented a new invention - a system that converts heat and light into electrical energy. In addition, the system also heats the water, so it is advantageous to put such a “sunflower” near residential complexes. The system is called HCPVT (highly efficient concentrated photovoltaic / thermal).
    The HCPVT design uses high-efficiency photocells that can convert high-temperature-focused sunlight into focused electricity with focus on reflectors (reflectors). Design reflectors were created by Airlight / Dsolar, and photocells were provided by IBM.

    The technologies and elements used in the construction are well known. The novelty is that the HCPVT uses both the thermal method of generating electricity and light (photocells).

    Reflectors are curved mirror panels. According to Airlight, aluminum foil proved to be the ideal material for such panels. It is an inexpensive material with high reflectivity. Nothing is needed to protect the reflector - the material is reliable enough, although very thin. The "flower" has only six "petals", each of which consists of six reflectors. At the focal point of 36 reflectors, 6 collectors are concentrated, one for each block of 6 reflectors.



    And just collectors are something new. Firstly, each collector is covered with an array of gallium arsenide photocells (GaAs). GaAs - converts light to electricity much more efficiently than silicon (38% in this case, instead of 20% for the most advanced silicon photocells). Of course, GaAs is a much more expensive material than silicon. But in HCPVT, gallium arsenide is not much - after all, they need to be covered only with the point on which the sun's rays are focused. On each HCPVT collector, gallium arsenide is covered with only a few square centimeters, and as a result we get one of the most efficient photocells in the world. Each collector generates about 2 kW of power; in total, HCPVT produces approximately 12 kW.


    IBM photocell with gallium arsenide

    Solar cells, like most semiconductors, lose their efficiency during heating. GaAs can work most efficiently at temperatures around 105 degrees Celsius. But the problem is that if you focus the light with reflectors at one point, then the temperature rises much higher. During the test tests, scientists melted a hole in the iron plate, focusing the rays on its surface. The temperature rose above one and a half thousand degrees. It is clear that some ways are needed to reduce such a high temperature. The problem was solved quite original.



    Cool with hot water


    IBM engineers began to use a solution that is already being used by the company to cool supercomputers. Namely, a liquid cooling system with hot water. In this case, there are differences - a “water block” was used, which is silicon with microfluidic channels. Several thousand of such channels are made, and through them water enters the heated structural elements. This solution can significantly increase the amount of heat that can be dissipated, microchannels in this regard are much more efficient than conventional channels, which are used in a standard cooling system.

    Such elements are mounted on the rear side of the photocells, which allows you to cool the site to the required temperature of 105 degrees Celsius. As a result, we get a system that produces 12 kW of electricity and 21 kW of thermal energy.



    System specifications

    disadvantages


    So far, the cost of such a system is tens of thousands of dollars, but this is only a test sample. In the future, the price of “sunflower” will fall if they establish mass production, and very significantly.

    In addition, HCPVT can only work with direct sunlight. Otherwise, the system will be ineffective. The "sunflower", however, has a positioning system that exposes the reflectors at the right angle. But there is also a cloud problem. If there are a lot of them, the system will not work properly.

    The energy generated by one “sunflower” will be enough for 3-4 households, no more, and all this will work only a few hours a day - while the sun is above the horizon. In order to meet the needs of even a small city using such a system, you will need a very large array of HCPVT.

    Well, the main problem so far is the cost of the “sunflower”, and, accordingly, the cost of electricity produced.
    Nevertheless, in the future, HCPVT will be improved, and the cost of its creation can be reduced. Such "sunflowers" are quite attractive, and they can be used by individual companies, government facilities, hotels and resorts.



    Solar sunflowers, or HCPVT in 2016, IBM and partners will begin supplying potential customers for testing, and mass production is planned to be launched by 2017. In the photograph shown above, the system is presented in full size. This is a working model, although not the final model.

    Only registered users can participate in the survey. Please come in.

    Do you think such a system has a future?

    • 24.4% Yes, of course 147
    • 58.8% Most likely yes, if you optimize the price of 354
    • 15.9% No, I don’t think so 96
    • 0.8% I have my opinion, unsubscribe in the comments 5

    Also popular now: