Craig Morris: Plug-In (Balcony) Solar Could Reach Mainstream By 2030

Once considered a niche or ‘gray area’ technology, plug-in solar – also widely known as balcony solar – is increasingly being viewed as an affordable and accessible entry point into distributed solar generation. This is particularly true for apartment residents and households unable to invest in larger rooftop systems.   

In this exclusive interview with TaiyangNews Senior Editor Anu Bhambhani, Bundesverband Steckersolar (BVSS) CEO Craig Morris discusses the evolution of Germany’s plug-in solar market, the interest it is generating globally, the role of batteries, regulatory and standards-related challenges, and why he believes the technology could see widespread global adoption by 2030. 

TaiyangNews: First things first, is it plug-in solar or balcony solar? How should one refer to it? 

Craig Morris: That's an excellent question to start off with. We define the technology as plug-in solar because what makes it special is the fact that a layperson can plug it in behind the meter into a standard power socket. Obviously, it's also called balcony solar because many systems are installed on balconies. 

But it is the same technology, whether it's installed on a roof, in a carport, in a garden, or even on a patio, plugged into an outdoor socket. The balcony aspect is important because people living in apartment buildings often cannot make decisions about the roof, or they would need group approval and additional cabling. With plug-in solar, you can simply put up 2 panels and connect them to an outdoor socket with a short cable. 

TaiyangNews: Rooftop solar is already a well-established segment of distributed generation in Germany. So how did it all start with plug-in solar? 

Craig Morris: In the early 1990s, a Dutch engineer developed microinverters. Traditionally, solar systems used one inverter for a string of panels, so if one panel was shaded, the performance of the entire string would drop. 

Microinverters allowed each panel to operate independently by converting DC into AC at the panel level. That wasn't originally about balconies, but because these inverters could work at such a small scale, people started experimenting with connecting just a couple of panels in gardens or other locations. 

At first, it was very slow – mostly hobbyists and tinkerers – because the technology was still expensive. Over time, people began asking whether it was safe and legal. That led to investigations, discussions on standards, and eventually the development of dedicated equipment, such as matched panel-inverter systems and mounting solutions for different balcony types. 

TaiyangNews: Earlier, there were reports of more than 1 million balcony solar systems installed in Germany. What is the status now in terms of units and capacity? 

Craig Morris: We do an annual review, and I saw in the press that Germany is now reporting 1.3 million registered units. But these are only the registered systems. As I mentioned, the market started in a gray area, so many systems are operating without registration. There are also indications that some people still do not register new systems even though registration is required. So, it is very likely that there are actually millions of systems operating in Germany today. 

TaiyangNews: What would you say are the key drivers for the growth of this market segment? 

Craig Morris: First of all, it is important to understand who buys these systems. Rooftop systems are better in many ways: they are larger, often better oriented, and more efficient. But they also require roofers and electricians, which increases costs significantly. 

A rooftop system might cost around $10,000, whereas in Germany today, 2 panels with an inverter and a mounting system can cost closer to €500. So, these systems appeal to people who either cannot or do not want to make the larger investment right away. 

For many households, plug-in solar is an entry point. In Germany, we estimate that a typical 2- or 3-person household uses around 2,000 to 3,000 kWh per year, and a system like this can cover around 50% of that electricity demand. 

TaiyangNews: What are the challenges for further growth, and how can they be overcome? 

Craig Morris: This is a very important issue, and we are currently working on a white paper about barriers and best practices, which will be published at Intersolar Europe 2026. We will present it at the Plug-in Solar Conference, a 1-day event taking place in Munich on June 24. If any of your viewers are going to Munich in late June, they are welcome to join. 

The barriers we are identifying come in a couple of different forms. First, this is still a very new technology. The word is getting out, but adoption is still uneven.  

One major barrier is getting politicians to understand that this technology exists and benefits people by allowing them to install small systems themselves. That requires community support and awareness so that the politicians see public demand. We do not yet have that in every country. 

What we look for in different countries is whether NGOs, consumer advocates, and environmental groups are talking about this. Are YouTubers covering and testing the technology? Are there subreddits and discussions on social media? Is the traditional media reporting on it? Awareness is still one of the biggest barriers. 

Another barrier is standards. Although this technology has been demonstrated to be safe in Germany, where insurers and firefighters do not see risks such as fires, electrical shocks, or panels flying off in storms, standards bodies focus first and foremost on safety. 

When they hear about a technology using a standard household plug with exposed pins, it challenges a long-standing safety principle. Normally, when you unplug something like a toaster, it is no longer generating electricity, so the pins are dead. With plug-in solar, people worry that, theoretically, electricity could still come out of the inverter if something malfunctions. 

In practice, the inverters switch off automatically, but standards bodies are cautious, and understandably so. This principle has worked for more than 100 years, and we are essentially asking for an exception. 

We have found that simply saying ‘it works in Germany’ is not always convincing because, for them, it still breaks the principle. What seems to work better is explaining that they actually need a standard to make these systems safer. 

If the standard requires a special plug, then an electrician has to install a new socket because ordinary consumers are not allowed to perform electrical work themselves. That would double the cost of the system. A €500 system could easily become a €1,000 system because another €500 would go toward the electrician’s visit. 

TaiyangNews: Are these also barriers for wider adoption across Europe? 

Craig Morris: Yes. In Germany, many installations are still being carried out in owner-occupied properties because residents can make decisions more easily there. 

Even though people now have the legal right to install these systems, apartment buildings and shared-ownership structures still create difficulties. Property managers and landlords are often hesitant, and many residents continue to face resistance even when the objections are not technically justified. 

TaiyangNews: With Europe promoting decentralized solar because of geopolitical risks, could this be a turning point for plug-in solar adoption globally? 

Craig Morris: Absolutely. I think by 2030, this technology will be widespread globally because the systems are mature and continuing to improve. 

About 75% of the systems sold in Germany now come with batteries. Batteries raise the price, but they also provide many benefits. They increase awareness because users monitor production and consumption through apps, and they can also support more flexible electricity use and dynamic pricing. 

TaiyangNews: There is now a lot of discussion around plug-in solar in the US, with more than 30 states pursuing policies. Do you see it becoming successful there? 

Craig Morris: Yes, but progress varies from state to state. There are already several websites tracking legislation across the US, and states such as Maine, Virginia, and Utah have adopted legislation for plug-in solar. Other states have seen bills stall, so the picture is mixed. I see the movement in the US is mainly happening at the state level rather than through national policy. 

TaiyangNews: Beyond Europe and the US, which countries do you believe could do well with plug-in solar, and what lessons can they learn from Germany? 

Craig Morris: I think once we move into the Global South, this becomes a very important topic, and it’s something we are currently investigating for the white paper we will present in June. 

The biggest challenge in many of these countries is affordability. In Germany, the United Kingdom, or the United States, many households may be able to afford a €500 system, especially if it pays for itself within 3 to 5 years. 

But we are speaking with people in Vietnam, where the average monthly income is below $500. In that context, the upfront cost becomes a major barrier. The same applies in countries like Brazil and South Africa. The payback period can still be very attractive, but many households may not have the upfront money. 

There are 2 possible models here: social leasing and PAYGO (pay-as-you-go) systems. In both cases, somebody else provides the system or the financing upfront. With social leasing, households repay the cost gradually through monthly payments, often similar to what they would already pay for electricity. In a PAYGO model, users top up the system in advance, and if they stop paying, they no longer receive electricity from it. 

There are also funding opportunities through JETP programs, climate finance, and development cooperation aid. 

What’s interesting is that these are essentially solar home systems. Similar off-grid systems were already being deployed in the 1990s. The World Bank invested heavily in rolling them out across different countries. I was in Morocco in 2009 studying one of these programs, where households used small systems to power TVs, lights, and radios. 

Since then, the technology has improved significantly and become much cheaper. Today, the same equipment can operate either connected to the grid or in off-grid mode. We can also do that in Germany, but because our grid is very resilient, the off-grid aspect is less important here. 

TaiyangNews: Looking ahead to 2030, in your crystal ball, where do you see plug-in solar? 

Craig Morris: I see this technology in Western countries increasingly being combined with batteries, and I hope people will realize that this can support the grid. 

For example, we are currently speaking with authorities in Poland, where there are concerns about excessive solar generation during midday, followed by a sharp drop later in the day. That creates challenges for the grid, and this is something every country is dealing with to some extent. 

But plug-in solar with batteries can actually become part of the solution. Once batteries are integrated, households can tailor electricity exports to what the grid needs, rather than simply feeding excess solar power into the grid at noon. 

In other countries, I see this technology improving grid reliability by helping bridge blackouts and brownouts for hours at a time. I also see it making electricity systems more distributed overall. 

In countries like South Africa, this could be especially useful, and probably in many other countries that we have not yet fully analyzed. 

Interestingly, we are also speaking with people in Papua New Guinea, and they are developing their own ideas about how this technology could support their grid operators. So, I’m also learning from them about the different ways plug-in solar could help improve grid resilience. 

TaiyangNews: Thank you.  

A short summary article of the interview is available here.