SOLAR CELLS EFFICIENCY

SOLAR CELLS EFFICIENCY

3 mayo, 2019 Off By admin

The efficiency of solar cells was increased year after year as a result of the use of new materials with which they manufacture solar cells

Imagine that you are thinking of installing solar panels for self-in your home, in your business … but you do not have too much free space on your roof or you want them to be of the highest possible quality.

In those cases you have to  look for the most efficient solar panels  on the market to make the most of your available space. And it is also that it is usually fulfilled that the most efficient solar panels are, coincidentally, the highest quality there is.

Currently, specifically, the LG Neon solar panels and the SunPower MAX3, MAX2 and P19 as winners. But we see it later.

SOLAR CELLS EFFICIENCY

It is very common, more than desirable, to find projects, tenders, offers today … They speak of solar panels with 16-17% efficiency as high efficiency panels, which is flatly false. An efficiency of  16-17% is something standard , it does not mean that it is neither good nor bad, it is simply something standard.

The high efficiency, in a solar panel, can be considered  from 19% .

It is also true that, nowadays, you can find many articles on the Internet that speak about the efficiency of solar panels, but after having reviewed many of them, we have to say that most of them are incorrect. Some are outdated  and  many are simply false  that only seek a commercial promotion.

The outdated articles  is why you should understand that solar cells are progressively improving their efficiency year after year, so that a solar panel of an X efficiency, probably in 1 or 2 years has improved. Therefore, the lists of most efficient solar panels should be updated, at least, every year.

The others,  the articles that are false , fall by their own weight. You will recognize why they usually talk about Chinese brands, why they show prices and why they do not provide any document that proves that, effectively, that is real and is superior to other panels. It is pure  commercial disinformation,  dishonest and without any rigor.

Well, in this article we will show what are  really  the 10 most efficient solar panels that exist in the photovoltaic market.

Technologies and efficiency of solar panels:

As you well know, in the photovoltaic sector there are 2 technologies that predominate, which are the Monocrystalline and the Polycrystalline. Well, but within the Monocrystalline there are also variations of technology, some conventional such as the PERC, the PERT … and other exclusive as the HIT of Panasonic and the IBC (Maxeon) of SunPower.

To see a  REAL graph  of technologies and their efficiencies, we show you a study  done by EnergyTrend in 2018  that shows exactly that, to a comparison of the types of technology that exist and their efficiencies:

SOLAR CELLS EFFICIENCY

Graph with efficiencies of solar cells and power of panel according to the technology used

Explaining a little the comparative graph of efficiency:

  • On the Y axis on the left, you can see panel power. That is,  up to what powers  are each of the solar panels coming depending on their technology.
  • On the X axis (the bottom one), you can see the  types of technology . From left to right they would be the P-Multi (Polycrystalline), the P-Mono (Monocrystalline) and the N-Mono (Monocrystalline of high purity).
  • On the axis on the right, you can see the  cell efficiency  in each case. Eye, cell efficiency, not panel (always something less).
  • On the green bars, the standard power of that technology is shown with the corresponding efficiency. That is, for example, for the P-Mono PERC, the standard is 300W with cell efficiency (not panel) of 21.4%.

As you can see, it is very illustrative that  the most efficient solar panels that exist  are those that incorporate the monocrystalline technologies HIT and IBC, which use type N silicon. That is, Panasonic and SunPower fundamentally.

And a little further away would come the panels that use Mono PERC technology with P-type silicon.

And finally, the least efficient solar panels are those that use Multi (Polycrystalline) technology also with P-type silicon.

As an aside , mention that the panels that use  type N silicon  are of a much higher quality than the rest, because that type of silicon is the purest that exists in the photovoltaic industry. While those that use  type P silicon , it is a type of silicon with some impurities, and that is why, in addition to other factors, it never reaches the efficiencies of a solar panel with type N silicon.

This is the reality of the photovoltaic sector when panel efficiency is concerned.

Table of the 10 most efficient solar panels that exist in the photovoltaic market:

Once the issue of the efficiencies of each technology has been clarified, we show the list of solar panels that have greater efficiency in the current photovoltaic sector. They are the following:

MAKERMODELPANEL EFFICIENCYPOWER PANELSIZE (length x width)
SunPowerSPR-X22-370 (Now MAX3-400)22.6%400W1.690 x 1.046 mm
SunPowerSPR-X22-360 (Now MAX3-390)22.1%390W1.690 x 1.046 mm
SunPowerMAX3-37020.9%370W1.690 x 1.046 mm
LGLG360Q1C-A520.8%360W1,700 x 1,016 mm
LGLG355Q1C-A520.6%355W1,700 x 1,016 mm
AUOSunForte PM096B0020.6%335W1,559 x 1,046 mm
SunPowerMAX2-36020.4%360W1.690 x 1.046 mm
AUOSunForte PM096B0020.3%330W1,559 x 1,046 mm
SunPowerMAX3-35019.8%327W1.690 x 1.046 mm
SHARPNQ-R256A19.8%256W1.318 x 980 mm
PanasonicVBHN330SJ5319.7%330W1.590 x 1.053 mm
PanasonicVBHN325SJ5319.4%325W1.590 x 1.053 mm
SunPowerSPR-P19-40019.4%400W2.067 x 998 mm

This would be an  updated version in March 2019 with the most efficient panels that exist in the current photovoltaic market . All of them are verifiable and verifiable, you can simply search the web of each manufacturer, the technical sheet of each of these panels and look where they indicate the efficiency of each of these models.

In this article  we have not considered bifacial solar panels , for one reason:

Being a type of panel of new implementation there is still no real data of how much more produced by its back face. In fact, it is absolutely unpredictable to know.

On the other hand, the aforementioned  current bifacial panels have a series of problems  with the shadows that project on the back of the cell the components of the panel, such as the junction box, the wires and even the panel frames, which in the long They can cause hot spots.

But let’s dig a little deeper on the two leaders in efficiency that exist in the market, we refer to the LG solar panels and the SunPower.

LG Neon Solar Plates:

As can be seen in the table above, after SunPower, LG solar panels, specifically Neon models, are the second solar panels that exist in terms of efficiency.

To understand how this high efficiency is achieved, it is best to see the scheme of  how the solar cell is used in LG Neon solar panels works :

 

SOLAR CELLS EFFICIENCY

The key is in what can be seen in the previous image. What LG does in its Neon solar panels, is to place the Bus Bar (those metallic tapes that go through conventional cells) through the back of the cell. In this way, it is possible to obtain a larger solar energy collection surface, better current circulation, better efficiency and better behavior at high temperature.

It is a more expensive technology than the conventional one but with  much greater reliability . One more step would be to eliminate those Bus Bar, because they are always a focus of problems.

In fact, the German TÜV laboratory, after examining thousands of photovoltaic installations, determined that  the most frequent problem  was corrosion and, on the other hand, that caused by the bus bar and metallic connections between cells.

SOLAR CELLS EFFICIENCY

Common failures in solar panels

As you can see in the previous image, 45.3% of the problems in a solar panel are caused by corrosion and almost 41% by breakage of connections between cells and bus bars.

 

Therefore, the final giant step for a reliable panel would be to eliminate those bus bars, and that is precisely what SunPower does

SunPower MAX solar panels:

Regarding SunPower solar panels, the leaders in terms of efficiency that exist in the market, there are some differences with respect to LG panels. We see it in a table:

SunPower Maxeon VS Cell Conventional Cell
It does not have front electrical contacts:
Therefore, it uses the entire surface of the cell to capture solar radiation and greatly improves efficiency and reliability compared to a standard cell.
SOLAR CELLS EFFICIENCYSOLAR CELLS EFFICIENCYFront electrical contacts:
This implies less radiation uptake by the space occupied by the electrical wires and more probability of corrosion with the passage of time.
Deposited on a solid copper base:
A thick copper foundation adds great strength and is almost immune to corrosion. Do not use Bus-Bar.
SOLAR CELLS EFFICIENCYSOLAR CELLS EFFICIENCYMetal paste in the back of the cell:
The cell can crack and lose power when exposed to temperature fluctuations.
Heavy-duty reinforced connectors:
The expansion and contraction of daily temperature oscillations is no problem for a SunPower cell with built-in expansion / contraction protection.
SOLAR CELLS EFFICIENCYSOLAR CELLS EFFICIENCYFine and weak connections:
If one of these connection between the panel is broken, the entire cell fails and the production of the panel will decrease by at least 33%.

As you can see, there is a big difference between SunPower and LG. While LG solar panels are still using Bus Bar technology (even though they are on the back of the cell), SunPower panels do not use those Bus Bars, so the reliability and efficiency is still greater than with LG.

So far the article today, which will be updated as new developments arise.

Since nobody is infallible, if you know other models of solar panels more efficient than those shown?, Contact us and we will analyze it to incorporate it into the list.

SOLAR CELLS FROM PEROVSKITA CRYSTALS EXCEED 20% EFFICIENCY

This material was previously used in the manufacture of cells for solar panels, but the equipment of the Federal Polytechnic School of Lausanne (EPFL) has managed to increase its efficiency above 20% by bringing these devices to the limit of their capacity. They discovered that if they reduced the pressure during the manufacture of perovskite crystals they achieved a performance as high as that of much larger plates.

The technique of the Swiss center consists of eliminating the volatile component of the perovskite glass layers by building them under vacuum, which is capable of producing regular and bright crystals of higher electronic quality. That means that they could process plates much more powerful and able to absorb more sunlight and create more energy in less time. The results were published in the journal Science.

The perovskite has a great advantage: it is low-cost technology, and at lower production costs more profit and more expansion of a technique that could increase alternative energy efficiency. However, they are still in the testing phase because, at the moment, cells of this type do not have the stability level of other materials.

But it is a great advance linked to the silicon industry and the construction of panels. The highest energy of the light would be absorbed by the upper layer of the perovskite plate, while the low energy light would be captured by the silicon layer. The combination would considerably increase the potential.

Read more about different types of solar panels