Technologies for Solar Power

The main articles are:

• Solar power (Russian market)
• Solar Power (Global Market)

2023

Japan develops technology to transfer solar energy from space to Earth

On May 27, 2023, it became known that Japan had developed technology for the transfer of solar energy from space to Earth. It is expected that this technology in the future will help the country solve a number of energy problems.

The idea is to generate energy in outer space using special devices with solar panels and then transmit it to ground-based receivers using microwaves. Due to the absence of an atmosphere, energy generation with the approach under consideration will not depend on the weather, and the ring system of satellites encircling the Earth will allow generating electricity around the clock. It is estimated that photovoltaic panels in geostationary orbit will be able to receive on average eight times more light than on the surface of the Earth. And this will make it possible to repeatedly increase efficiency.

Japan has developed technology to transfer solar energy from space to Earth

In March 2015, the Japan Aerospace Exploration Agency (JAXA) conducted a successful experiment to transmit 1.8 kW of energy via microwaves at a distance of 50 m. The next step is to send energy at a distance of 1 to 5 km vertically. In fiscal 2025, Japanese researchers intend to organize a full-fledged experiment based on several small satellites: they will be used to transmit energy "for hundreds of kilometers."

According to the Nikkei resource, the scientific program is headed by Professor Naoki Shinohara from Kyoto University. The project is supported by the Japanese Ministry of Economy, Trade and Industry. However, the main obstacle to the practical implementation of the initiative remains cost. To generate about 1 GW of energy - the equivalent of one nuclear reactor - with the help of a space solar station, investments of more than $7 billion will be required.^[1]

Photocells have been created in Russia that generate electricity from the light of ordinary light bulbs

On May 4, 2023, Russian researchers from the University of Science and Technology MISIS in Moscow announced the development of a perovskite solar cell with a record efficiency with a different combination of light colors. The product is capable of charging gadget batteries from any household light bulb.

Solar panels based on perovskite thin-film photocells provide a number of advantages over traditional silicon solutions. In particular, new generation solar panels are cheaper to manufacture and have good flexibility due to the possibility of using a plastic substrate. The peculiarity of advanced Russian development is that its optical properties allow you to effectively convert light of various color temperatures into electricity.

Scientists have developed a perovskite cell capable of charging gadget batteries from any household light bulb

The presented perovskite solar cell has an increased bromine content, which is 2.5 times more efficient than silicon under different combinations of light colors, that is, under different lighting conditions. In "warm" light (cozy yellowish glow), the developed material gives the maximum possible (as of the beginning of May 2023) efficiency (efficiency) for perovskite photovoltaics - 36.1%.

It is assumed that the new technology will allow the manufacture of flexible solar panels capable of operating in low light conditions. Such elements can be integrated, for example, into low-power devices of the Internet of Things - various sensors, smart devices with low power consumption, etc.

High bromine perovskite is extremely effective in converting colors of different color temperatures into electricity under so-called hot light (1700 K). Brom in this case helps shift the edge of the absorption spectrum into the field of high-energy photons, - said Nigina Talbanova, co-author of the work, engineer of the laboratory of the Promising Solar power at MISIS University.[2]

Solar panels began to be installed between the rails

In mid-March 2023, a start-up Sun-Ways based in the Swiss city of Ekyublan unveiled new technology to allow solar panels to be mounted between rail tracks. More. here

2020: Scientists from St. Petersburg have found a way to reduce the cost of highly efficient solar panels

On February 4, 2020, ITMO reported that a group of scientists from St. Petersburg proposed and experimentally tested a technology for creating highly efficient solar panels based on A3V5 semiconductor connections on a silicon substrate, which in the future may have an efficiency of one and a half times higher and at the same time lower cost than photovoltaic converters with one stage. The appearance of this technology was once predicted by the Nobel laureate Zhores Ivanovich Alferov. The results of the work of scientists are published in the journal Solar Energy Materials and Solar Cells.

ITMO noted that when the world's reserves of hydrocarbon fuel sources are reduced and public concern about the environment is growing, scientists are paying close attention to the development of so-called "green technologies." One of the most popular topics is the development of solar power.

However, the increased use of solar panels is hampered by a number of problems. Silicon solar panels that have become traditional have relatively little efficiency - about 20-25%. More efficient technologies require markedly more complex semiconductor connections, which significantly increases the price of the solar cells themselves.

Petersburg scientists proposed a solution to this problem. Researchers from ITMO University, Zh.I. Alferov Academic University and A.F. Ioffe Institute of Physics and Technology have shown that A3B5 structures can be grown on a cheap silicon substrate, which will significantly reduce the cost of a multi-stage solar cell.

"Our work is devoted to the creation of efficient solar cells based on A3V5 on a silicon substrate. The main difficulty of synthesizing semiconductor compounds on a silicon substrate is that the semiconductor must have the same crystal lattice parameter as silicon. Roughly speaking, the atoms of this material must be at the same distance from each other as the silicon atoms. Unfortunately, there are few semiconductors that meet this requirement. For example, gallium phosphide (GaP). However, it itself is not very suitable for creating solar cells, as it does not absorb sunlight well. But if you take GaP and add N nitrogen, we get a GaPN solution. Already at low N concentrations, this material becomes straight-wave and absorbs light well, while it can be integrated onto a silicon substrate. At the same time, silicon is not just a foundation on which photographic material is synthesized - silicon itself can act as one of the photoactive layers of the solar cell that absorbs light in the IR range. One of the first ideas of combining A3B5 structures and silicon was voiced by Zhores Ivanovich Alferov, " noted Ivan Mukhin, ITMO University Fellow, Head of Laboratory, Academic University

In the laboratory, scientists managed to get the top layer of the solar battery integrated on a silicon substrate. If there are more such photoactive layers, then the efficiency of the solar battery will become significantly higher, since each layer of the solar battery will effectively absorb its part of the solar spectrum.

So far, the laboratory has created the first small prototype of a solar battery based on A3V5 elements on a silicon substrate. For February 2020, scientists are faced with the task of creating a solar cell that has several photoactive layers. Such solar panels are noticeably more efficient at absorbing sunlight and generating electrical energy.

'We've learned how to grow the uppermost layer. This system of materials can potentially be used for intermediate layers as well. If you add arsenic As, you get GaPNAs - from it on a silicon substrate you can grow several cascades operating in different parts of the solar spectrum. As our previous work has shown, the potential efficiency of such solar panels can exceed 40% at light concentration, that is, 1.5 times higher than in modern Si technologies. " noted Ivan Mukhin, ITMO University Fellow, Head of Laboratory, Academic University

2019

New semiconductor material for solar panels created in Russia

A group of Russian scientists has created a new semiconductor material without the use of lead, which can be used in solar panels to improve their efficiency. This was announced on May 13, 2019 by the press service of one of the participants in the study of the Skolkovo Institute of Science and Technology (Skoltech).

"Cooperation of researchers from Skoltech, A.V. Nikolaev Institute of Inorganic Chemistry of the Siberian Branch of the Russian Academy of Sciences (SB RAS) and the Institute of Problems of Chemical Physics of the RAS made it possible to create promising lead-free semiconductor materials for use in solar panels based on complex halides of antimony and bismuth. The results of the study were published in the Journal of Materials Chemistry and announced on its cover, "the report said.

Of great interest for use at present are solar panels based on complex lead halides, that is, lead compounds with elements of the 17th group of the periodic table of Mendeleev (fluorine, chlorine, bromine or iodine), with a perovskite structure - reminiscent of the structure of the mineral perovskite, the crystals of which have a cubic shape. Such batteries are low cost, easy to manufacture, and highly efficient to convert light.

Mass production and introduction of perovskite batteries is currently limited by two factors: the low stability of complex lead halides and the toxicity of these compounds. Therefore, the development of alternative lead-free materials, in particular on the basis of bismuth and antimony halides, is actively underway around the world. However, all previously obtained samples have low light conversion efficiency. A team of Russian scientists proved that the cause is the suboptimal structure of bismuth and antimony compounds.

"We found that the low dimension of the anion lattice of such compounds (zero, sometimes 1D and extremely rarely 2D) does not allow the smooth transport of holes and electrons necessary for the efficient operation of solar cells. As a result, materials of this class can demonstrate effective work in lateral photodetectors, but do not work in solar cells, "said Pavel Troshin, professor at the Skoltech Energy Research Center, quoted in the message.

Physicists have developed a fundamentally new material for solar panels based on perovskite-like complex antimony bromide (ASbBr6, where A is an organic positively charged ion). Solar panels based on this material showed record efficiency of light conversion for antimony and bismuth halides. According to Troshin, this work opens up fundamentally new opportunities for the development of perovskite electronics.

A non-toxic method for producing nanosilicon for use in solar cell coatings has been found at Moscow State University

On February 13, 2019, it became known that scientists at Moscow State University found a non-toxic way to produce silicon nanomaterials. In the production of silicon nanostructures, which are in demand in various fields of industry, as a rule, quite toxic hydrofluoric acid is used. Employees of Moscow State University named after M.V. Lomonosov found a way to avoid its use. The discovery of MSU scientists can find application in the industrial production of nanosilica-based anti-reflective coatings for solar panels, optical sensors for detecting various molecules, nanocontainers for drug delivery. The study was carried out with the support of the Russian Science Foundation (RNF), its results were published in the international journal Frontiers in Chemistry. Read more here.

Cold energy: 'Anti-solar battery' works at night

Engineers have created a device that can be called a wind-up solar battery: it generates current not when it absorbs photons, but when it emits them. Such an energy source could power various equipment at night, giving heat stored by the Earth's surface to the^[3].

The development is described in a scientific article^[4], published in the journal Applied Physics Letters by a group led by Shanhui Fan of Stanford University.

As is known, heated bodies emit radiation. This is easy to make sure by raising your hand to the hot battery (better on the side so that the upward flow of warm air does not interfere). If the object does not receive as much thermal energy from the external environment as it emits, it cools down. To cool the object more efficiently, you need to allow it to freely exchange photons with as cold a medium as possible.

Back in the 20th century, physicists theoretically calculated, and in recent years they experimentally demonstrated the effect of negative light. It consists in the fact that the photodiode can generate electricity not only by absorbing photons coming from the external environment (as in a conventional solar battery), but also, conversely, giving them away and cooling due to this. Energy stored in the device in the form of heat is spent on this process.

To operate such a device, you need a cold environment into which photons will leave without returning. And such an environment is at hand, or rather, above our heads: this is outer space.

"The vast universe is a thermodynamic resource," Fan says. "From the point of view of optoelectronic physics, there is a really very beautiful symmetry between the collection of incoming radiation and the collection of outgoing radiation."

Of course, if such an emitter is simply launched into orbit (and prevent it from warming up from the Sun, keeping in the shadows), it will quickly light up all its heat, equalize in temperature with the space vacuum and stop generating energy.

However, on Earth, it can be provided with thermal contact with the surface of the planet. As soon as the photocell becomes colder than the surrounding bodies, the energy deficit will be replenished due to thermal conductivity. Thanks to this, photons will still regularly fly into icy outer space through an atmosphere that is quite transparent at wavelengths of 8 to 13 micrometers (a narrow band in the middle infrared range). Part of the energy of the radiation leaving the installation will be converted into electrical.

This is the device created by the authors of the new work. They chose the compound mercury, cadmium and tellurium (HgCdTe) as the material for the photodiode. This substance effectively emits precisely in the desired wavelength range. After passing through a hemispherical gallium arsenide (GaAs) lens and a barium ferride (BaFe2) window, the photons enter a parabolic mirror sending them straight into the sky. To get to the diode from the outside, the radiation needs to go the same way in the opposite direction. All these tricks are needed so that the installation exchanges photons almost exclusively with space, and receives energy from the Earth due to thermal conductivity.

The experimental installation in the Fang group experiments generated 64 nanowatts per square meter of surface. Of course, devices cannot be powered from such power. However, as the authors calculated, the theoretical limit, taking into account the influence of the atmosphere, is 4 watts per square meter. This is much less than modern solar panels (100-200 watts per square meter), but quite enough to power some devices.

To bring the power of the installation closer to this mark, you need to select a material for the photodiode with a more pronounced negative light effect. Currently, researchers are busy looking for such a substance.

According to the authors, the same principle can be used not only to collect the energy of the Earth's surface heated by the Sun, but also to utilize the heat generated during the operation of various mechanisms.

2018

An iron-based molecule has been created that can "capture" the energy of sunlight

On December 4, 2018, it became known that some photocatalysts and solar cells are based on technology that includes molecules containing metals. Their task is to absorb the rays and use their energy. As of December 2018, metals in these structures are rare and expensive - for example, ruthenium, osmium and iridium.

For December 2018, our results suggest that with advanced molecular design, rare metals can be replaced with iron, which are common in the Earth's crust and therefore cheap. Kenneth Wernmark, Professor of Chemistry at Lund University

Together with colleagues, he worked to find an alternative for expensive metals. The researchers focused on iron, which is significantly easier to mine. Scientists have created their molecules based on iron, its potential for use in solar energy has been proven in previous studies.

For December 2018, in this study, the scientists moved one step further and developed an iron-based molecule capable of "capturing" and harnessing the energy of sunlight for a long enough time for it to react with another molecule.

The study is published in the journal Science. The molecule could be used in the following kinds of photocatalysts to produce solar energy, the researchers said. In addition, the results reveal other potential applications of iron molecules, for example as materials in LEDs.^[5]

Researchers bring solar cell efficiency closer to normal

On October 5, 2018, it became known that the researchers brought the efficiency of the solar battery closer to the usual one. Solar is considered the most sustainable option to replace fossil fuels, but technologies to convert it into electricity must be very efficient and cheap. Scientists from the Energy Materials Division of the Okinawa Institute of Science and Technology believe they have found a formula for making low-cost, high-performance solar panels.

To do this, Professor Yaobing Qi, the leader of the study, identified three conditions that will lead the technology to market introduction and successful commercialization. According to him, the speed of converting sunlight into electricity should be high, inexpensive, as well as durable.

As of October 2018, most of the commercial photocells that are used in batteries are made of crystalline silicon. It has a relatively low efficiency of about 22%. Ultimately, this leads to the product being expensive for the consumer, and their only motivation to buy is to take care of nature. Japanese scientists suggest solving the problem with perovskite.

Perovskite cell studies are very promising. According to data for 2018, in just nine years their effectiveness has grown from 3.8% to 23.3%. Other technologies took more than 30 years of research to reach the same level. Jaobing Qi, Study Leader

The Japanese method of processing the mineral increases its efficiency to crystalline silicon elements. To do this, the researchers coated transparent conductive substrates with perovskite films that absorb sunlight very efficiently. They also covered the substrate with a layer of potassium triiodide with a small amount of chlorine ions and methylamine gas - this allowed them to make uniform panels from approximately equal amounts of photocells. When developing the method, scientists realized that the creation of a perovskite layer with a thickness of 1 microns significantly increases the life of the photocell - it did not change after 800 hours of operation.^[6]

2017

Russian scientists have found a way to increase the efficiency of solar panels

In 2017, Russian and Swiss researchers studied the effect on the structure and performance of solar panels of changing the ratio of components from which the light-absorbing layer of the perovskite solar cell is formed. The results of the work are published by^[7] in the Journal of Physical Chemistry^[8].

Organ-inorganic perovskites were first developed five years ago, but they have already overtaken the most common and more expensive silicon solar cells in terms of efficiency. The structure of perovskites contains crystalline compounds in which the solvent molecules of the starting components are located. The dissolved components, falling out of solution, form a film on which perovskite crystals grow. The scientists isolated and described three intermediates that are crystallosolvates of one of the two solvents most commonly used in the creation of perovskite solar panels. For the two compounds, scientists first established a crystal structure.

"We found out that the key factor determining the functional properties of the perovskite layer is the formation of intermediates, since perovskite crystallites inherit the form of intermediates. This, in turn, affects the morphology of the film and the efficiency of solar panels. This is especially important when obtaining thin films of perovskite, since the needle or thread-like shape of the crystals will lead to the fact that the formed film will be discontinuous, and this will significantly reduce the efficiency of such a solar cell, "said the head of the study Alexei Tarasov

In addition, the authors investigated the thermal stability of the obtained compounds and calculated the energy of their formation using quantum chemical modeling. We have also found that the crystal structure of the intermediate determines the shape of the perovskite crystals formed, which determines the structure of the light absorbing layer. This structure, in turn, affects the performance of the resulting solar battery.

The study was carried out by researchers at Moscow State University in collaboration with scientists from the Kurchatov Center for Synchrotron Radiation, the Peoples' Friendship University of Russia, St. Petersburg State University and the Federal Polytechnic School of Lausanne in Switzerland.

Smart glass for windows invented in Sweden

Scientists from the University of Gothenburg have developed a special glass coating capable of "collecting" solar energy. The coverage is based on nanotechnology. Special antennas from plasmons are able to capture and store energy from the environment. The surface covered with such a substance heats up, while the glass does not change physical characteristics: it remains transparent, does not distort colors and retains refractive properties^[9].

Scientists have been exploring this area for a long time and are looking for a development application. In the modern world, this technology is relevant, since the heat loss of houses due to windows is approximately 20%. Scientists believe that their invention can also be used to insulate various objects.

British scientists invent glass bricks with solar panels

A team of scientists at the University of Exeter in England has developed glass wall blocks with built-in solar panels. The architectural portal Archdaily writes about this. Blocks can be used in construction homes instead of regular bricks.

The building material was called "Solar Squared." As tests in the university's laboratory have shown, in addition to generating electricity, the blocks have a number of other useful properties. In particular, the walls built in this way allow sunlight into the building well and retain heat in the premises.

To promote the product, scientists have created an innovative company, The Build Solar. An investor search is underway. The introduction of "solar tiles" to the market is tentatively scheduled for 2018.

Solar panels made of "smart" glasses

A group of scientists at Prieston University has developed fundamentally new transparent solar panels based on "smart glasses." Relevant research was carried out at the Endlinger University Center for power and Environmental Protection^[10].

Among the main advantages of the new transparent panels are that they will not require additional power when generating energy. In addition, such coatings can be glued to almost any windows on the inside. "The existing technologies of" smart "glasses require electricity, and it is difficult to install them in buildings where this was not provided in advance," the publication said. Therefore, the new technology can be considered a breakthrough.

When generating energy, innovative panels reduce their transparency by absorbing some of the light of the so-called near ultraviolet part of the spectrum. Owners of premises with smart windows glued to windows will be able to control this process using a smartphone. Thus, they will be able to choose what they need at a particular moment: light or electricity. "This will increase energy efficiency, make staying more comfortable and protect your personal life," said one of the authors of the invention, Lou Nicholas Davy.

RKS introduced the Electrical Protection System for Solar Panels

In early 2017, Holding Russian space systems"" (RKS, part of the State Corporation Roskosmos"") completed the creation of a modernized electrical protection system for solar panels domestic production. Its use will significantly extend the life of spacecraft power supplies and make Russian solar panels one of the most energy efficient in the world. More. here

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