At a sustainability trade show in Berlin, a new gadget caught Waltraud Berg’s eye: a solar panel small enough to easily mount on the side of a balcony and then plug into a wall outlet to power her home directly with energy from the sun.
“I was absolutely thrilled to learn that such a thing existed, that you could produce your own energy and be more independent,” said Ms. Berg, a retiree who installed several panels herself on the south-facing balcony of her Berlin apartment.
Each of these lightweight panels produces just enough electricity to charge a laptop or run a small refrigerator. But in German homes, they are powering a silent transformation, putting the green revolution within people’s reach without having to make a big investment, find an electrician or use heavy tools.
“No need to drill or hammer anything,” Berg says. “Just hang them on the balcony like wet laundry in Italy.”
More than 500,000 of these systems have already been installed in Germany, and new laws easing rules on installing solar panels have helped boost their use. In the first six months of the year, the country added nine gigawatts of photovoltaic capacity, or the amount of solar power produced by one system, according to the Federal Network Agency, a German regulator.
“We are seeing a continued increase in solar installations in particular,” said Klaus Müller, the agency’s president. “Compared to the total capacity at the end of 2023, solar capacity has increased by almost 10 percent. Two-thirds of this capacity has been installed on buildings, which includes balcony systems.”
As part of its efforts to wean itself off Russian natural gas, the European Union wants to quadruple the amount of electricity it generates from photovoltaic sources by 2030, to 600 gigawatts. Germany wants to reach a third of that amount by the same year. Germany is expected to add more solar power capacity this year than any other European country, according to Rystad Energy.
Some of the solar panels sold in Germany are made by European companies, but most are produced in China, whose dominance of the global industry allows it to supply solar panels at increasingly lower costs, said Nicholas Lua, an analyst at Rystad Energy.
“Small-scale panels benefited from the same economies of scale that China’s solar manufacturing system has,” he said.
In the early 2000s, Germany encouraged individuals to install solar panels on their roofs by paying them fees, called feed-in tariffs, for sending energy to the grid. But in recent times, these incentives have become less lucrative, making such large-scale investments less attractive.
So-called “plug-in” systems involve routing the direct current generated by the panels to an inverter, which converts it into alternating current. They can then be plugged into a standard wall outlet to supply electricity to a home.
Janik Nolden, who with two friends founded Solago, a German startup that sells rooftop solar panels and rechargeable versions, said most of his customers were interested in installing the panels themselves.
Most of the panels he sells are made in China, where the quality is better and prices are lower than those produced in Europe. “If my customers asked for panels made in Europe, I would have them in stock,” he said. “But that’s not the case.”
In response to questions from DIYers, Nolden began posting videos online explaining how the panels work, as well as how to plan, install and optimize them. “DIY is the future,” he said. “People want to do as much as possible themselves.”
The company, which started out as a small storefront in suburban Düsseldorf, has since grown to fill a warehouse roughly the size of a square Manhattan block, with 50 employees helping to ship eight truckloads of deliveries across the country and to neighboring Austria.
Elsewhere in Europe, rechargeable solar panels are popular in the Netherlands, and interest is growing in France, Italy and Spain, partly thanks to steadily falling prices.
In Germany, individual plug-in panels are sold from 200 euros in supermarkets. Complete kits, including fixings, an inverter and cables, cost around double that.
Electricity prices in Germany have risen after Russia’s invasion of Ukraine and are now around 25 euro cents per kilowatt hour. However, they remain among the highest in Europe.
The measure’s appeal in Germany is heightened by recently passed laws that prevent owners and cooperative boards from blocking solar panel installations and remove some of the most onerous registration requirements.
Together, these changes have made the idea of installing a personal solar system attractive to a broader consumer base.
“We’re seeing more diversity, more older people, more women,” said Christian Ofenheusle, founder and CEO of EmpowerSource, a company that promotes small-scale solar power. He said a growing user group is young people with families who are concerned about climate change.
“They say they want to make a contribution,” Ofenheusle said. “Even if it means saving less than 100 euros a year, they will gladly accept it because it is for the next generation.”
A recent development is the introduction of small-scale batteries that allow users to store electricity generated during peak hours for use in the evening or at night.
The apps allow users to check at any time how much electricity they are producing. For some, this function has become as addictive as social networks or video games, sparking friendly rivalries between neighbors, but also sharpening their desire to make further savings.
When Thomas Losch first heard about a neighbor’s solar installation—several solar panels connected to smart meters that allowed the neighbor to optimize his electricity use—he scoffed at the idea.
But he got curious and two months ago he bought his own set of solar panels to install on the roof of his garage. Now, the first thing he does every morning is open his app to check how much electricity is being produced.
“I’m now completely addicted to producing energy from the sun,” he said. “It’s become like taking a drug.”
This phenomenon is not uncommon, Nolden said. Many of his customers who buy smaller plug-and-play kits then come back to order a complete roof system.
After just two months of installing the small system in his garage, Losch said he’s already considering the possibilities of powering things he could with a full rooftop setup, such as an electric vehicle with a larger battery.
His system already generates enough energy during the day to run portable air conditioners in the upstairs bedrooms of his home. But beyond the financial savings, he expresses a certain satisfaction in taking steps to reduce his carbon footprint.
“It’s not like I’m saving the world, but I’m doing my part,” he said. “It’s a nice feeling.”