The efficiency of solar panels has doubled. Top quality solar panels – black, monocrystal
Everyone knows perfectly well that the higher the efficiency, the better. This rule also applies to efficiency solar panels. Thanks to new technologies and production methods, the efficiency of photocells is constantly growing, albeit very slowly, but the main thing is that progress does not stand still.
Below is a graph of performance achievements different manufacturers, over time. Starting from the middle and to the very top, semiconductors were developed for new records and space tasks, the cost is appropriate. Everything below is already available and can be purchased nowadays.
Everyone knows about efficiency, but few people understand where these percentage values come from and how they are calculated. Let's try to figure it out.
As a rule, the manufacturer indicates the efficiency of its assembled modules and the efficiency of the individual solar cells that make up the solar battery. These parameters, as well as other characteristics, are indicated under the so-called standard conditions - STS, the main ones being insolation of 1000 W/m² and element temperature of 25 ° C, at which they are taken technical specifications, including efficiency.
Currently, conscientious manufacturers have begun to test each solar battery they produce after assembly and make a printout of individual parameters, which is included with each battery. This is done to confirm the quality of their products.
Below is a printout of one of the SY-100 solar panels from Suoyang energy:
Each module has its own individual characteristics. If you take two identical panels of the same model, they will still have slightly different parameters.
Solar panels of this manufacturer have positive tolerance, as a result we have 104.617 W and an efficiency of 15.74% ( separate element 18.7%). How did he get this value?
The formula for calculating the efficiency of solar panels is as follows:
Efficiency = Psb/Ssb/10, where:
Psb – SB power;
Ssb – area of the SB.
Let's substitute the values into the formula:
Efficiency = 104.617/(1.2*0.554)/10 = 15.74%
Everything fits together, but another question arises: why then is the efficiency of individual photocells higher? The answer is simple - the whole point is that the solar battery consists of many photocells and between them there is short distance, which is not used to generate energy, plus the aluminum frame also “takes up space”, accordingly the area increases, and the efficiency decreases.
Below are photos and videos of some attempts to make solar cells more efficient by creating complex shaped cells, forcing solar cells to cool, and focusing light using lenses. Perhaps the new products will perform well, they will be put into mass production, and they will become available to you and me.
This is a Vitru hybrid solar battery; in the fight for efficiency, the manufacturer is struggling with the heating of the elements. The water in the bulb cools the elements, as a result of which the voltage does not decrease and the power does not drop.
The new product is not yet on sale and is in the testing stage, but as V3Solar states, the whole secret is in the conical shape and rotation of the structure, thanks to which the cells do not have time to heat up and the efficiency does not decrease throughout the day.
Modern researchers who work on solar systems constantly debate among themselves about the efficiency of solar panels. This is one of the main criteria on the basis of which their effectiveness and level of productivity are assessed. Because the cost of converting solar energy into electricity for panels remains high, manufacturers are worrying about how to make them more efficient.
It is known that per 1 m² of cell area produces about 20% of the total solar radiation power that hits the battery. In this case, we are talking about the most favorable climate and weather conditions, which do not always happen. Therefore, to increase the rate, you need to install a lot of solar panels. This is not always convenient, and the cost is a pretty penny. Therefore, you need to understand how feasible it is to use these alternative energy sources and what prospects there are in the future.
So, the efficiency of a battery is the amount of potential it actually produces, expressed as a percentage. To calculate it you need power electrical energy divided by the power of solar energy falling on the surface of the solar panels.
Now this figure ranges from 12 to 25%. Although in practice, taking into account weather and climatic conditions, it does not rise above 15. The reason for this is the materials from which solar batteries are made. Silicon, which is the main “raw material” for their manufacture, does not have the ability to absorb the UV spectrum and can only work with infrared radiation. Unfortunately, due to this deficiency, we waste the energy of the UV spectrum and do not use it beneficially.
Relationship between efficiency and materials and technologies
How do solar panels work? Based on the properties of semiconductors. The light that falls on them causes its particles to knock out electrons located in the outer orbit of the atoms. Large quantity electrons create potential electric current- under closed circuit conditions.
To provide normal indicator power, one module will not be enough. The more panels, the work more efficiently radiators that supply electricity to batteries, where it will accumulate. It is for this reason The efficiency of solar panels also depends on the number of modules installed . The more of them there are, the more solar energy they absorb, and their power indicator becomes an order of magnitude higher.
Is it possible to improve battery efficiency? Such attempts were made by their creators, and more than once. A way out in the future may be the production of elements consisting of several materials and their layers. The materials are arranged in such a way that the modules can absorb different types energy.
For example, if one substance works with the UV spectrum, and another with the infrared, the efficiency of solar cells increases significantly. If we think at the theoretical level, then the highest efficiency could be about 90%.
Also, the type of silicon has a great influence on the efficiency of any solar system. Its atoms can be obtained in several ways, and all panels, based on this, are divided into three varieties:
- polycrystals;
- elements from .
Solar batteries are produced from monocrystals, the efficiency of which is about 20%. They are expensive because they have the highest efficiency. Polycrystals are much lower in cost, since in this case the quality of their work directly depends on the purity of the silicon used in their manufacture.
Elements based on amorphous silicon have become the basis for the production of thin films. The technology for their manufacture is much simpler, the cost is lower, but the efficiency is also lower - no more than 6%. They wear out quickly. Therefore, to improve their service life, selenium, gallium, and indium are added to them.
How to make your solar panel work as efficiently as possible
The performance of any solar system depends on:
- temperature indicators;
- angle of incidence of the sun's rays;
- surface condition (it should always be clean);
- weather conditions;
- presence or absence of shadow.
The optimal angle of incidence of the sun's rays on the panel is 90°, that is, straight. There are already solar systems equipped unique devices. They allow you to monitor the position of the luminary in space. When the position of the Sun relative to the Earth changes, the angle of inclination of the solar system also changes.
Constant heating of the elements is also not in the best possible way affects their performance. When energy is converted, serious losses occur. That's why You should always leave a small space between the solar system and the surface on which it is mounted . The air currents passing through it will serve as a natural way of cooling.
Cleanliness of solar panels - also an important factor influencing their efficiency. If they are very dirty, they collect less light, which means their effectiveness is reduced.
Also correct installation plays a big role. When installing the system, do not allow a shadow to fall on it. The best side on which it is recommended to install them is the south.
Moving on to weather conditions, we can at the same time answer the popular question of whether solar panels work in cloudy weather. Of course, their work continues, because electromagnetic radiation emanating from the Sun hits the Earth at all times of the year. Of course, the performance of the panels (efficiency) will be significantly lower, especially in regions with a lot of rainy and cloudy days a year. In other words, they will generate electricity, but in much smaller quantities than in regions with a sunny and hot climate.
A little about the efficiency champion batteries
Record holder for efficiency in solar systems at at the moment German batteries are considered. They were created at the Institute of Solar Energy named after. Fraunhofer. They are based on photocells consisting of several layers. Company "Soytek" has been actively introducing them into widespread consumption since 2005.
The elements themselves are no more than 4 mm thick, and sunlight focuses on their surface using special lenses. Thanks to them, light particles are converted into electricity, and the efficiency is as much as 47%.
Second place is deservedly occupied by panels created by using photocells from three layers of the company "Sharpe". These are also solar panels with high efficiency, although slightly less - 44%.
The three layers are represented by three substances: indium (gallium) phosphide, gallium arsenide and indium (gallium) arsenide. Between them there is a dielectric layer used to obtain a tunnel effect. As for the focusing of light, it is obtained by using the known Fresnel lens. The light concentration is reached to a level of 302 times, and then enters a three-layer semiconductor converter.
Of course, such an efficiency record can hardly be accessible to a wide range of consumers. By the way, Elon Musk, a famous American billionaire, is the owner of the company "Solar City". Not so long ago, in 2015, Musk’s company developed a “consumer” version of solar panels with an efficiency exceeding 22%.
Developments and numerous laboratory experiments are carried out to this day. You can be sure that such technologies have a great future - as an environmentally friendly alternative source of energy.
The record holder for efficiency among solar batteries available on the market today are solar batteries based on multilayer photocells, developed by the Fraunhofer Institute for Solar Energy Systems in Germany. Since 2005, their commercial implementation has been carried out by Soitec.
The size of the photocells themselves does not exceed 4 millimeters, and focusing sunlight on them is achieved by using auxiliary concentrating lenses, thanks to which saturated sunlight is converted into electricity with an efficiency reaching 47%.
The battery contains four p-n junction, so that four different parts of the photocell can effectively receive and convert radiation of a specific wavelength, from sunlight concentrated 297.3 times, in the wavelength range from infrared to ultraviolet.
Researchers led by Frank Dimiroth initially set themselves the task of growing a multilayer crystal, and a solution was found - they spliced growth substrates, and the result was a crystal with different semiconductor layers, with four photovoltaic subcells.
Multilayer photocells have long been used on spacecraft, but now solar stations based on them have been launched in 18 countries. This is becoming possible thanks to improved and cheaper technology. As a result, the number of countries equipped with new solar stations will increase, and there is a tendency for competition in the market for industrial solar panels.
In second place are solar batteries based on Sharp three-layer photocells, the efficiency of which reached 44.4%. Indium gallium phosphide is the first layer of the solar cell, gallium arsenide is the second, and indium gallium arsenide is the third layer. The three layers are separated by a dielectric, which serves to achieve a tunnel effect.
The concentration of light on the photocell is achieved thanks to a Fresnel lens, like the German developers - the light of the sun is concentrated 302 times and converted by a three-layer semiconductor photocell.
Scientific research into the development of this technology has been continuously conducted by Sharp since 2003 with the support of NEDO, a Japanese public management organization promoting scientific research and the development and dissemination of industrial, energy and environmental technologies. By 2013, Sharp had achieved a record of 44.4%.
Two years before Sharp, in 2011, the American company Solar Junction had already released similar batteries, but with an efficiency of 43.5%, the elements of which had a size of 5 by 5 mm, and focusing was also carried out by lenses, concentrating the light of the sun 400 times. The solar cells were three-junction germanium-based cells, and the team even planned to create five- and six-junction solar cells to better capture the spectrum. Research is still ongoing by the company.
Thus, solar panels made in combination with concentrators, which, as we see, are produced in Europe, Asia, and America, have the highest record efficiency. But these batteries are mainly manufactured for the construction of ground-mounted solar power plants large scale and for efficient power supply of spacecraft.
Recently, a record has been set in the field of conventional consumer solar panels, which are affordable for most people who want to install them, for example, on the roof of a house.
In mid-autumn 2015, Elon Musk's company SolarCity introduced the most efficient consumer solar panels, the efficiency of which exceeds 22%.
This indicator was confirmed by measurements carried out by the Renewable Energy Test Center laboratory. The Buffalo plant already sets a daily production target of 9 to 10 thousand solar panels, the exact characteristics of which have not yet been reported. The company already plans to supply at least 200,000 homes annually with its batteries.
The point is that optimized process allowed the company to significantly reduce the cost of production, while increasing the efficiency by 2 times compared to widespread consumer silicon solar panels. Musk is confident that his solar panels will be the most popular among homeowners in the near future.
IN lately Solar energy is developing at such a rapid pace
Recently, solar energy has been developing at such a rapid pace that in 10 years, the share of solar electricity in global annual electricity generation has increased from 0.02% in 2006 to almost one percent in 2016.
Dam Solar Park is the largest solar power plant in the world. Power 850 megawatts.
The main material for solar power plants is silicon, the reserves of which on Earth are practically inexhaustible. One problem is that the efficiency of silicon solar cells leaves much to be desired. The most efficient solar panels have an efficiency of no more than 23%. And the average efficiency rate ranges from 16% to 18%. Therefore, researchers around the world involved in the field of solar photovoltaics are working to free solar photoconverters from the image of a supplier of expensive electricity.
A real struggle has unfolded to create a solar supercell. The main criteria are high efficiency and low cost. The National Renewable Energy Laboratory (NREL) in the USA even periodically issues a newsletter reflecting the interim results of this struggle. And each episode shows the winners and losers, the outsiders and the upstarts who accidentally got involved in this race.
Leader: solar multilayer cell
These helium converters resemble a sandwich of different materials, including perovskite, silicon and thin films. In this case, each layer absorbs light only of a certain wavelength. As a result, these multilayer helium cells, with an equal working surface area, produce significantly more energy than others.
The record-breaking efficiency of multilayer photoconverters was achieved at the end of 2014 by a joint German-French research team led by Dr. Frank Dimroth at the Fraunhofer Institute for Solar Energy Systems. An efficiency of 46% was achieved. This fantastic efficiency value was confirmed by an independent study at NMIJ/AIST - the largest metrology center in Japan.
Multilayer solar cell. Efficiency – 46%
These cells are made up of four layers and a lens that concentrates sunlight onto them. The disadvantages include the presence of germanium in the structure of the substrate, which slightly increases the cost of the solar module. But all the shortcomings of multilayer cells can ultimately be eliminated, and researchers are confident that in the very near future their development will leave the walls of laboratories and enter the big world.
Rookie of the Year - Perovskite
Quite unexpectedly, a newcomer intervened in the race of leaders - perovskite. Perovskite is common name all materials having a certain cubic crystal structure. Although perovskites have been known for a long time, research into solar cells made from these materials only began between 2006 and 2008. Initial results were disappointing: the efficiency of perovskite photoconverters did not exceed 2%. At the same time, calculations showed that this figure could be an order of magnitude higher. Indeed, after a series of successful experiments, Korean researchers in March 2016 received a confirmed effectiveness of 22%, which in itself became a sensation.
Perovskite solar cell
The advantage of perovskite cells is that they are more convenient to work with and easier to produce than similar silicon cells. With mass production of perovskite photoconverters, the price of one watt of electricity could reach $0.10. But experts believe that as long as perovskite helium cells reach maximum efficiency and begin to be produced in industrial quantities, the cost of a “silicon” watt of electricity can be significantly reduced and reach the same level of $0.10.
Experimental: quantum dots and organic solar cells
This type of solar photoconverter is still at an early stage of development and cannot yet be considered as a serious competitor to existing helium cells. However, the developer, the University of Toronto, claims that according to theoretical calculations, the efficiency of solar cells based on nanoparticles - quantum dots - will be above 40%. The essence of the invention of Canadian scientists is that nanoparticles - quantum dots - can absorb light in different spectral ranges. By changing the size of these quantum dots, it will be possible to select the optimal operating range of the photoconverter.
Solar cell based on quantum dots
And considering that this nanolayer can be applied by spraying onto any, including transparent, base, then practical application There are promising prospects for this discovery. And although today laboratories have achieved an efficiency rate of only 11.5% when working with quantum dots, no one doubts the prospects of this direction. And the work continues.
Solar Window – new solar cells with 50% efficiency
The Solar Window company from Maryland (USA) has introduced a revolutionary “solar glass” technology that radically changes traditional ideas about solar panels.
Previously, there were reports about transparent helium technologies, as well as that this company promises to significantly increase the efficiency of solar modules. And, as recent events have shown, these were not just promises, but 50% efficiency - no longer just the theoretical delights of the company’s researchers. While other manufacturers are just entering the market with more modest results, Solar Window has already presented its truly revolutionary high-tech developments in the field of helium photovoltaics.
These developments pave the way for the production of transparent solar cells, which have significantly higher efficiency compared to traditional ones. But this is not the only advantage of the new solar modules from Maryland. New helium cells can be easily attached to any transparent surfaces (for example, windows), and can work in the shade or under artificial light. Due to their low cost, investments in equipping a building with such modules can pay for themselves within a year. By comparison, the payback period for traditional solar panels ranges from five to ten years, which is a huge difference.
Solar cells from the Solar Window company
Solar Window Company has announced some details new technology obtaining solar cells with such high efficiency. Of course, the main know how was left out of the equation. All helium cells are made primarily of organic material. The layers of elements consist of transparent conductors, carbon, hydrogen, nitrogen and oxygen. According to the company, the production of these solar modules is so environmentally friendly that it has 12 times less environmental impact than the production of traditional helium modules. Over the next 28 months, the first transparent solar panels will be installed in some buildings, schools, offices and skyscrapers.
If we talk about the prospects for the development of helium photovoltaics, it is very likely that traditional silicon solar cells can become a thing of the past, giving way to highly efficient, lightweight, multifunctional elements that open up the broadest horizons for helium energy. published
I scream and cry, this is probably how the video should have started, but many people immediately start thinking in the wrong direction. Yes, there is a lot of material about the efficiency of solar panels. There are so many that everyone is looking for a solar panel with an efficiency of 30 -50% and no matter how much they cost. Wait, what? Are you really one of those people who think that today the efficiency of panels is what is in open access it's not enough. In reality, is 22 -28% not enough?
Do you want an example of what actually has low efficiency, and we’ll talk about solar panels produced in 1990 with an efficiency of about 10%, and you know, now I can definitely say with confidence that the fairy tale that everyone who doesn’t understand is spreading According to the Internet, this is outright untrue. And in order to say this with confidence, I needed to buy 2 panels with my own money, install them in operation, and monitor them for about a year different options connections.
Well, the verdict is ready.
The efficiency of older solar panels of earlier production before 2010 is significantly lower than the efficiency of modern panels, and here we are not even talking about the reduction in cost of the latter, but rather about the production technology. We will not touch on the fact that modern ones are thinner, have a new absorbent coating, which is more effective than older panels and fades less. No, we'll just talk about efficiency.
To begin with, what is efficiency - coefficient of performance.
So, in simple language, this is how efficient solar panels work now, but not in the future, since the further and longer the solar panel works, the efficiency getting lower. What if you pull and load solar panels? short circuit, spiral, or IR lamps, as some do. The efficiency of solar panels will simply melt several times faster.
So, there really is no such information, even if it is so rough, especially since solar panels are so worn out that it is difficult to find in our country. And what do we end up with?
It’s simple: when there is sun, the solar panels produce almost all their power, but the operating and idle voltages drop. Yes, the current dropped a little, about 0.5 - 1A. And we could end here, taking into account the words of most bloggers, but no, our efficiency has also dropped, now solar panels produce less both in voltage and current, in cloudy weather or in reflected light. This is a drop in efficiency or wear of the panel. It seems to work, but it doesn’t seem to work in bad weather.
You think everything, but that’s not the case, I’m already used to telling everything or almost everything, even if slippers are flying at me in the present time, and in the future they are collected saying, but why didn’t you know :) I’ll tell you another problem with worn-out solar panels.
Namely! The point is that due to wear and tear solar panel and a heavily damaged and burnt-out absorbent and light-absorbing coating, by the way, some people who are not in the know call this coating a scattering coating or something else. But correctly absorbing and absorbing light, its task is to protect the silicon wafer, and the structure of the element itself, and absorb sunlight more effectively! Much of the efficiency depends on this thin layer.
So, when it collapses and burns out, the solar cells begin to heat up more intensely, and their power drops. The effect is very similar to a semi-pierced or overheated semiconductor, which seems to work, but heats up and its characteristics drop. So, since a solar cell is the same conductor with p-n transition, only larger size All electronics rules also apply to solar cells.
And the most important thing is that you cannot combine old solar panels with new ones, because when the output power on the weak ones drops, but on the new ones there is still power, the old panels will draw part of the power onto themselves as a load, thereby heating the street instead of working!
That's how things are. And now I will talk about this more often, so that the majority of both storytellers and people who are not in the subject will have more competent information. And if there are real observations, then there is information on how to extend the life of solar cells.