Earlier this year I wrote about alternatives to rooftop solar, and all the many ways you can benefit from solar power without investing in a full scale installation. The most intriguing of those alternatives is balcony solar, which has been booming in Germany over the last couple of years. Known as balkonkraftwerk, there are now millions of balcony solar installations across the country.
Solar balconies have now spread to Spain, the Netherlands and France. Belgium recently legalised them and they are catching on in China. The UK is investigating. Legislators in the United States are laying the legal frameworks for it. We’re going to be hearing a lot more about DIY solar, on balconies and beyond.
The technology behind this rapid growth is the plug-in solar system. These are solar kits that are sold on a DIY basis, with no expensive installation costs. In some contexts it doesn’t even need an electrician. You simply hook the panels over your balcony railing and plug them into a wall socket. I didn’t quite believe that when I first read it, but it really can be that simple.
The kit includes a micro-inverter that supplies electricity directly into the home’s electricity circuit. Since these systems are small, almost all the electricity generated will be used on the spot by appliances. You could consider it to be providing baseload power to the house, running the fridge and the wi-fi. Very little is exported, which means it’s not disruptive to wider grid management. Households tend to save 20-30% on their bills.
While plug-in solar has been popularised on balconies, it has plenty of applications. Many are being installed on garages and sheds, on walls and indeed rooftops. I’ve seen early adopters in the UK who have them fitted vertically to their fences and plugged into the outdoor socket usually used for the lawnmower.
Those with a working knowledge of electricity will spot some potential risks with this sort of thing. Running too much power into the wiring in this way could present a fire risk, and so systems have to be small scale. There’s a shock risk from the live plug pins. Ideally micro-solar would be on a separate circuit and signed off by an electrician. Network operators are supposed to be notified when a house has solar installed, for safety reasons. This doesn’t always happen – Germany has 780,000 officially registered plug-in solar systems, but an estimated 4 million in operation. Since kits can be ordered online, it’s tricky to keep up with what’s actually being used. The availability and affordability of the technology is running ahead of legislation. Like electric scooters, they’re in something of a legal grey area at the moment in many places.
That’s why there’s a delay on plug-in solar in the UK, and why I wouldn’t recommend them myself just yet. They are on the market already, with start-ups developing kits with work-arounds to meet local standards, and a company called Eco-flow getting the early buzz. If they start to catch on, illegal kits will no doubt proliferate quickly, just as they have with e-bikes and those aforementioned e-scooters. So the government should move quickly to provide clarity. A dozen countries or so have done this already, and we can learn from them about how to enable and encourage safe DIY solar. The latest from government is an action point in their Solar Roadmap, published earlier this year, which promises to “conduct a safety study this year with the aim of unlocking opportunities for plug-in solar”. So watch this space.
Do it well, and the potential is huge. It’s solar generation that is available to renters and those on lower incomes. It would democratise renewable energy. It would bring down bills and give people a stake in the energy system in a new way. There’s a political urgency to this in the UK too, as climate sceptic newspapers and politicians are gaining ground at the moment. DIY solar would make the benefits of clean energy tangible and available to everyone. It’s hard to be against net zero policies when you can see them working for you so directly, and I look forward to seeing if DIY solar can change the conversation in the coming months.
The Earthbound Report 
Have now recommended your blog as well, for what it’s worth! ; )
Interesting as we have had a plug in solar panel for our caravan installed nearly 20 years ago, but whilst we can plug it in it has its own wiring that we had electrics put in by caravan service people. In summer we have been able to stay off grid for 10 nights using the solar panel to top up the leisure battery. Though staying on conventional sites where electric is included nowadays we tent to use the electric as otherwise we are using bottle gas for fridge and cooking.