Germany has over a million plug-in solar users, but Finland bans them

More than one million people in Germany use small plug-in solar systems to generate electricity, while self-installed systems remain illegal in Finland, Yle reports.

Jero Ahola, a professor of energy efficiency at LUT University, says Finland should consider allowing small solar power systems that consumers can install themselves.

Known as balcony solar or plug-in solar systems, they usually consist of one or two panels with a maximum output of about 800 watts. Users connect the system to a household socket, and the electricity can cover part of the home’s consumption.

Ahola says at least 10 European Union countries have approved plug-in solar systems. The United Kingdom was the latest to allow them, while no Nordic country has yet approved their use.

In Germany, a small balcony system can cost less than 500 euros and can be connected to a home’s electrical network through a plug. The approval process has been kept to a minimum.

In Finland, installing a small system is theoretically possible, but it requires the same permits as a larger system and a separate electrical installation. Ahola says the resulting bureaucracy and installation costs make the systems impractical and unprofitable.

Safety authority warns of fire risks

The Finnish Safety and Chemicals Agency, Tukes, says Finland’s current electrical standards do not permit plug-in solar systems.

Tukes warned this summer against connecting the systems independently to a home’s electrical network. According to the agency, doing so is illegal and creates electrical safety and fire risks.

Tukes says feeding electricity from a solar panel directly through a socket bypasses the electrical network’s fuses and could overload a home’s wiring, creating a fire risk. A socket connection may also prevent the network from being reliably de-energised, endangering maintenance workers and rescue personnel.

Ahola says Tukes’ concerns are reasonable but notes that the systems have been widely used elsewhere in Europe for several years. He urges Finland to examine Germany’s experience and base its decision on the available evidence.

“The statistics will show whether the risks have materialised, because Germany has one million users,” Ahola said. “If they have not, perhaps we do not need to be so concerned.”

Ministry begins investigation

Pekka Grönlund, an industry counsellor in the Energy Department of Finland’s Ministry of Economic Affairs and Employment, says plug-in solar power has recently become an increasingly common topic in the ministry’s discussions with various parties.

The ministry is preparing an investigation into the issue. It wants to examine the safety aspects and international experience with the systems, Grönlund said.

The matter is also being considered by Sesko, Finland’s electrical standardisation organisation. New electrical standards will enter into force in 2027.

Sesko would allow plug-in solar systems under certain conditions, but says they should not be connected to a home’s electrical network through a standard socket. It proposes creating a new product category requiring different kinds of safe connections and commissioning procedures.