Zoom Image

Tandem solar cell: The material perovskite can also convert the blue light components into electricity

Photo: Johannes Beckedahl / Lea Zimmerman / HZB

At the moment, the main criticism about the restructuring of our energy system is that it is too expensive, too slow, not enough. There is already a lot of good news and new reasons for optimism:

1. The solar expansion target for 2023 has already been achieved

The German government has set itself the goal of covering at least 2030 percent of gross electricity consumption in Germany from renewable energies by 80. Renewable electricity already accounts for more than 56 percent of the total load. The share of production is over 59 percent. That's right – there's still a lot of work to be done. The good news is that nine gigawatts were set as the expansion target for solar power capacity for 2023. In fact, this value was already reached last week.

Now this is not enough to meet the needs of our economy. Especially in the future, when transport, buildings and as many industrial processes as possible are electrified. For 2023, the contribution of photovoltaics is expected to be 215 gigawatts to meet the needs. This means that the expansion must become faster every year. Higher remuneration and tax incentives are intended to contribute to this – but progress is being made!

Admittedly, the situation of wind energy is less encouraging. Last week, only 52 percent of the targeted additional capacity of 3.9 gigawatts had been achieved. One reason for this is that transport permits for components of wind turbines that have been available for a long time are being issued too slowly. In the last three months of the year, however, the pace urgently needs to increase. The fact that some approval processes have been simplified should help.

2. Electricity prices on the stock exchange have fallen again

If you're still paying 35 cents per kilowatt-hour or more for your electricity, it's because you're stuck on an expensive contract. New customers are already paying less than 30 cents.

Now, some may argue that electricity in Germany is still particularly expensive. However, this is mainly due to the fact that we currently continue to burn expensive gas to generate electricity. And the price is always determined by the power plant with the highest generation costs – this is the "merit order" principle.

There are already phases in which the price of electricity is zero or even negative. And phases in which the entire load is covered by renewables. If you are interested in such numbers, just follow this and this Twitter/X account. Or take a look at the Fraunhofer platform "Energy Charts" from time to time.

3. Price collapse for solar power and storage

Renewable energy prices are falling faster and faster, and have been for many years. Again and again, the plummeting costs for solar and wind energy push through the "But it won't get any cheaper now" limit predicted by the International Energy Agency (IEA).

In fact, electricity generation from solar power has become 87 percent cheaper within ten years, and storage in batteries by 85 percent. This is the result of a recent study by the Berlin-based climate research institute MCC, which was published in the journal "Energy Research & Social Science". Wind power, heat pumps and other fossil-free technologies are also experiencing a sharp drop in prices. As the MCC reports, batteries already cost less than 100 US dollars per kilowatt hour – "significantly less than was predicted for 2030 in a publication from two years ago," according to a press release accompanying the study. According to the authors, the price premium for battery storage, which makes solar power flexibly available in an optimal mix, is to fall from the current 2030 percent to only 100 percent by 28.

4. Solar cells become more productive

Not all sunlight that hits a solar cell is converted into electricity. For example, simple silicon cells can now be produced for little money, but they mainly process the red and infrared frequency range. More than 29 percent efficiency is not possible in this way. The most efficient silicon cells available to private buyers today manage about 25 percent. But now there are materials that can do more.

For some years now, a particularly hot candidate has been a class of crystalline substances called perovskite. Perovskite can also convert the blue light components into electricity. If these materials are combined in a solar cell with silicon in so-called tandem cells, the upper limit no longer applies. Every few months, a new world record for efficiency is set. According to the constantly updated hit list of the National Renewable Energy Laboratory of the USA, the current one is 33.7 percent efficiency. There are even more efficient techniques in the lineup, but they are much more expensive and time-consuming. When two teams with tandem cells broke through the 30 percent mark, this July's "Science" was worth two scientific articles and an additional expert commentary.

Researchers from several companies and various other institutions around the world are working on perovskite and tandem cells. Eike Köhnen from Helmholtz-Zentrum Berlin – a team from the center temporarily held the world record for research tandem cells in July – estimates when asked: It takes a maximum of five years for such products to be ready for the market. But it could also be much faster.

In any case, there is a broad international consensus that further increases in efficiency are not only possible, but very likely. And a market-ready, affordable solar cell that generates a quarter to a third more electricity from sunlight than the best on the market to date would change the industry once again.

5. Renewable energies are booming worldwide

It is also undisputed that renewable energies are on the road to success worldwide. According to Bloomberg NEF, 80 percent of the world's power generation capacity added last year was renewable. And in 2022, more capacity was added worldwide than ever before.

According to the MCC research team, there are calculations "according to which all global energy consumption in 2050 could be completely and cost-effectively covered by solar and other renewables," said Felix Creutzig, lead author of the current study, in a statement. An "extremely optimistic scenario", as he himself admits. But it makes it clear that a fossil-free future is possible.


Christian Stöcker

The Great Acceleration

Publisher: Pantheon

Number of Pages: 384

Publisher: Pantheon

Number of Pages: 384

Buy for €16.00

Price inquiry time

24/09/2023 17:51 p.m.

No guarantee

Order from Amazon

Order from Thalia

Order from Yourbook

Product reviews are purely editorial and independent. Via the so-called affiliate links above, we usually receive a commission from the merchant when making a purchase. More information here

Certainly, a united effort is needed to ensure that renewable energies really triumph over fossil fuels. The world market is extremely dynamic – the introduction of import tariffs for solar modules, which is currently being considered in some places, is therefore a bad idea. What slows down, harms. And we are in a hurry.

6. Now an accelerator is added

So progress is happening – faster than it sometimes seems. Optimism is in order. Also because exponentially growing markets and exponentially falling prices are now meeting machine learning as a tool. Experts assume that artificial intelligence acts as an exponential turbo – machine learning, for example, has only been increasingly used for the further optimization of perovskite cells in recent years. The current efficiency records were still achieved without it.

And constantly accelerating developments have a special characteristic: they always provide surprises.