Solarletter #15_EN - What has happened in Germany since the closure of nuclear power plants?
Also: France, 912 MWp awarded in the latest tender, Commissioning of the largest photovoltaic park in Europe and TOPCon modules, a promising future
Please note that text below has been translated from the spanish version by using AI
Hello everyone and welcome back to Solarletter. My name is Imanol Matanza, and I aim to share with you the latest news, technological advancements, and trends in the field of photovoltaic energy. Through Solarletter, I hope to provide you with valuable information, market analysis, state-of-the-art updates, and practical tips that will help you stay informed about the latest developments in the photovoltaic industry.
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This edition has been a bit overwhelming for me, I do not want to deceive you. The visit from some childhood friends has coincided with a vacation and the start of construction on my next project. I always wonder why days couldn't have a couple more hours...
Alright, let us go with a couple of interesting pieces of news!
What has happened in Germany since the closure of nuclear power plants?
This news is not 100% related to photovoltaics; however, it is relevant to the energy transition. So let us take a look. For those who are not familiar with Fraunhofer ISE, it is one of the leading research and development laboratories in photovoltaics in Europe, located in Freiburg, Germany.
Exactly one year ago, on April 15, 2023, the last three nuclear power plants in Germany were shut down. Remember that here, when the "Energiewende" or German energy transition began, it was decided to start with the closure of nuclear power plants. The Fukushima accident and the weight of the coal industry (I will leave a photo below for you to see its magnitude), motivated German politicians to start closing nuclear power plants. Now, the Fraunhofer Institute has released a summary of what happened in the last year (Link, by Bruno Burger).
In the year before their closure, nuclear power plants in Germany produced a total of 29.5 TWh, accounting for 6.3% of electricity production. The question was how to replace this loss. Would it be replaced by coal production or through imports? Well, the answer lies in renewables, as they produced 33 TWh more than the previous year. 58.8% of electricity between April 2023 and April 2024 came from renewables.
On the other hand, production from fossil sources was 154.4 TWh, a 26% reduction compared to the previous year.
There are several reasons for the reduction in generation from fossil sources:
A 2.1% drop in consumption to 459 TWh. Private consumers and industries have reduced their consumption, partly due to self-consumption.
Germany went from exporting 21.3 TWh the previous year to importing 23 TWh this year. Here they clarify that the restart of French reactors, along with high hydropower production in the Alps and Scandinavian countries, has helped to keep German coal-fired power plants in check.
Finally, they show that electricity prices have returned to pre-Ukraine war levels.
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France, 912 MWp awarded in the latest tender
In the latest French government auction in early March, a total of 912 MWp out of 925 MW were awarded (by Serena Qian). Distributed among a total of 92 projects, the average price reached was €81.9/MWh.
Only projects ranging from 500 kWp to 30 MWp were eligible to participate in the auction. However, the limit did not apply to those to be installed in unused areas, such as quarries or abandoned industrial sites.
A total of 34 promoters were awarded, 21 of whom received less than 20 MWp. Among the three largest awardees, we have:
The French state-owned company EDF with 191.4 MWp, accounting for 21%.
Neoen with 118.9 MWp, accounting for 13%.
Urbasolar with 78.3 MWp, accounting for 9%.
The largest projects in this auction are the "Centrale Photovoltaïque de Variscourt" in the north with a total of 69 MWp and the floating installation "Centrale Photovoltaïque flottante du Cheylas" of 45 MWp in the south, at a pumping station.
On the other hand, the French government issues a new decree with feed-in tariff prices for private and industrial self-consumption. With this new decree, the French government sets incentives for installations smaller than 3 kWp at €0.153/kWh and around €0.117/kWh for installations between 100 and 500 kWp.
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Commissioning of the largest photovoltaic park in Europe
Up to now, the photovoltaic park "Francisco Pizarro" in Extremadura, Spain, was the largest in Europe, with a total capacity of 590 MWp. This record has been surpassed by the developer Move on Energy, which has just begun the commissioning of the "Witznitz Energy Park" project, south of Leipzig, Germany. Currently, it already has a total of 605 MWp installed, but still lacks another 45 MWp to be installed.
With an impressive number of 1.1 million modules, it will reach its maximum of 650 MWp by summer, becoming the largest photovoltaic park in Europe. They have needed to occupy a total of 500 hectares, to which another 150 hectares of compensatory measures are added.
The project was financed by Hansainvest Real Assets, and for this purpose, they have closed a 15-year PPA with Shell Energy Europe. The project has been built on a former open-pit coal mine.
As a curiosity, here in Germany, it is complex to see such large-scale parks. The land is very divided among owners, and expropriation is not an option. The only region where such projects are taking place is in the East Germany area, where larger plots were created after collectivization during the communist period.
Although Iberdrola has lost the top spot, it will not be for long, as they have already secured the environmental impact study for a 1.2 GW promotion in Portugal. This will be built with the help of Prosolia Energy, and it is expected to be connected to the grid by 2025.
Certainly, incredible figures that are difficult to imagine... I hope to someday come across one of these giants, truly engineering megaprojects.
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TOPCon modules, a promising future
In a recent study by the "National Platform for Energy Storage and Photovoltaic Experiment Verification," the effectiveness of TOPCon technology alongside string inverters (Solarbe Global) has been confirmed.
The study, published on March 28, shows results similar to those obtained in 2022 with n-type cell modules. Compared to PERC modules, it demonstrates a production increase of 2.87%. Additionally, they claim that there are noticeable differences when comparing different manufacturers of the same technology, which can reach up to 1.63%.
On the other hand, they also quantify the differences between different technologies in terms of degradation rate.
On the flip side, the prices of n-type cells continue to decrease (PV-Magazine). This week, they have decreased by 3.3%, reaching a price of 55 CNY/kg to 60 CNY/kg (€7.25/kg to €7.91/kg).
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Edition´s microtip
It is time for the edition's tip, let us talk about "half-cut cells". Surely, most of you will immediately think of one of their main advantages. And that's because with the module divided in two, even if its bottom half is shaded, the top half is still able to produce without affecting the entire module. Is this true? The answer is, it depends, depending on the operating point of the module or string.
It is often mistakenly considered that even if the bottom half of a module is shaded, its top part will continue to produce normally. However, if this module is connected to a string with multiple modules, it probably won't produce anything (its bypass diodes will activate, allowing current to flow). The current that can flow through this module will be limited to half. So, there will be two options: limiting the current to the rest of the modules in the string, or bypassing it to allow the rest to continue producing at 100%.
Let us consider a simple example:
Let's consider a module through which 10 A can flow. It is also a "half-cut" module, in which both halves are connected in parallel with bypass diodes every 2 cell columns. In a normal operating case, 5 A will flow through the top part, while the remaining 5 A will flow through the bottom part. When there is partial shading on the bottom part of the module, there will be two points of maximum power:
The bypass diodes do not activate, so only 5 A flows through the top part of the module (Red Zone).
The first two bypass diodes activate, allowing 10 A to flow through them, which then distribute to the last columns, both bottom and top, with 5 A flowing through each (Yellow Zone).
Back to the string case, let us say it has 30 modules connected in series. Do we force them all to produce only 5 A, or do we separate the problematic module so that the other 29 can continue to carry 10 A?
Still, the idea of cutting cells in half brings significant benefits in improving module performance. Here are some that come to mind:
Dividing the current in two reduces Joule losses.
With reduced Joule losses, cells improve their performance due to lower operating temperatures.
With less current flowing, smaller busbars are required, increasing the active part of the cell and reducing material costs.
If you want to delve further into the subject, here is a video from GSES that explains the proper functioning of half-cut cells in a simple way.
That concludes the edition. I hope you enjoyed and it made your coffee break, public transportation ride, or nap more enjoyable. If you have any suggestions, recommendations, or comments, feel free to reply to this email.
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Sunny Regards!