More Europeans Using ‘Plug-and-Play’ Solar Energy Systems to Electrify Their Homes
A new green energy craze is sweeping through Germany. Tiny solar power plants are popping up on balconies across the country, giving citizens the ability to take power directly from the sun and into their homes.
According to data from Germany’s Federal Network Agency (Bundesnetzagentur), demand is soaring for these plug-in balcony photovoltaic systems. Official figures suggest the number of registered systems has grown in the country from around 137,000 in 2022 to well over 400,000 in 2024—and the trend doesn’t seem to be slowing down.
This surge in balcony voltaic systems is thought to be spurred by several overlapping drivers, including climate change, Russia’s invasion of Ukraine, and skyrocketing energy prices. Given the right support and conditions, this simple, effective energy source could soon become more than a German zeitgeist (“the spirit of the time”) phenomenon and spread to homes around the world.
What Is Balcony Solar?
Much like solar farms and rooftop panels, balcony solar devices use photovoltaic cells to capture energy from sunlight and convert it to electricity. Also known as plug-in solar devices, they consist of small solar panels installed on available balcony space, either directly onto the railings or on stands. These plug-and-play systems do not need professional installation, giving an opportunity for those living in apartments or without access to a roof or large outdoor space to join the solar revolution.
The panels gather energy from sunlight to generate direct electric current. This is then converted via an inverter into the alternative current used in major energy grids. The system can then be plugged into an electrical outlet, adding solar-generated electricity straight into a household’s electrical system.
Electricity created by these devices [balcony solar panels] can be used to power or charge appliances directly, which helps to bring down electricity costs.
Electricity created by these devices can be used to power or charge appliances directly, which helps to bring down electricity costs. It gives everyday citizens a way to make their own lives less reliant on fossil fuels. In some cases—depending on local regulations and grid systems—electricity can even be fed back into the grid for a financial reward.
What About Efficiency?
Of course, the efficiency of solar panels depends on the amount of accessible sunlight. This means the energy generation capacity of balcony solar panels is necessarily limited, compared to rooftops, which can generally accommodate larger and greater numbers of panels.
Solar panels are able to produce around 15 watts (W) on average per square foot. A 10-square-foot balcony could therefore produce around 150W during “peak sun hours”—where sunlight intensity is an average of 1,000W per 10.5 feet. Balcony solar systems can also be combined with battery storage packs to store excess electricity for use during cloudy weather or at night—or if the electricity grid fails.
Balcony solar systems can also be combined with battery storage packs to store excess electricity for use during cloudy weather or at night—or if the electricity grid fails.
There are other factors to consider. Balconies that are partially shaded by natural or man-made structures will see their energy production reduced. The orientation of an apartment can drastically affect how much sunlight it receives and how much electricity it can produce. In Germany, a 400W balcony solar system facing southwards at the right angle will generate around 320W on average; yet this would fall to half in slightly cloudy weather.
As is the case with many renewable energies, shifting weather patterns affect how much electricity is generated. In British summers, which can provide around five peak hours per day, this balcony could produce 750 watt-hours (Wh) though this figure would fall dramatically during the winter. Moreover, even though solar panels on balconies may not be as exposed as on rooftops, they are still vulnerable to strong winds and must be secured. Snow and hail can affect both balcony solar panels and rooftop panels.
Cost Considerations
If well maintained, solar panels usually last around 25 years. Ideally, one would want to recuperate one’s investment in the balcony power plant beforehand to make it worthwhile economically. Costs for solar panels and balcony solar systems vary. But if a 360W capacity balcony solar power system costs around $2,000 in the US, it could take up to 25 years to break even, depending on energy prices and weather conditions over that period.
In Germany, economic incentives appear to be a major driver behind the success of plug-in solar plants. In January 2023, the German government made balcony generators exempt from VAT (value-added tax). In Europe, the average costs of these systems can range between €1,500-3,000 (about $1,630 to $3,261), some are available for less than €300 (about $326). Many of the costs are heavily subsidized by German states and/or municipalities (with direct subsidies of up to €500, or about $543) and can range up to €1,450 (about $1,576) per system depending on size and capacity.
Another reason behind Germany’s balcony solar boom is that many citizens live in apartments, making small solar systems an enticing option. Compared with US residences, German homes demand far less energy: On average, German families use around 3,500 kWh of electricity per year while in the US, electricity demand is roughly triple that per household. Ironically, US electricity costs are a lot less—$0.13 / kWh compared with $0.52 / kWh in Germany.
Streamlining Solar Regulations
Germany has relaxed legislation surrounding balcony solar systems to further boost uptake, setting an example for like-minded European countries like Austria and Switzerland. In April 2024, the German government passed “Solarpaket 1,” a set of legal reforms including a simplified grid connection procedure for balcony power systems. The energy threshold for registration of balcony plants has also been raised from 600W to 800W.
The German government passed … a set of legal reforms including a simplified grid connection procedure for balcony power systems.
Regulations can be more complex elsewhere, however. In the US, balcony power systems can require the same permits as large rooftop systems, making the whole process more onerous. In New York, height limits for balcony systems are set at 10 feet due to citywide building restrictions. While planning permission generally isn’t required, state and local restrictions may apply, which could be the deciding factor in whether someone chooses to invest in such a system. That being said, people wishing to install a balcony solar system in the US may be eligible for a federal solar tax credit.
But the potential is staggering for an American balcony solar revolution similar to that seen in Germany. Some estimates suggest plug-in balcony systems in the US could generate over 108 million MWh/year— four times the amount generated by the country’s solar industry in 2015—and offer somewhere in the order of $13 billion per year in energy savings.
The case of Germany shows how political will, funding, and the relaxation of red tape can dramatically increase uptake in this new, clean energy source. Inviting citizens into the energy creation process could transform consumers into “prosumers” who are more environmentally minded.
While a country’s energy consumption profile doesn’t turn on one system, balcony solar systems could have a measurable impact if their adoption could reach a critical mass.
*Richard Kemeny writes about archaeology, marine biology, oceanography, ecology, technology, and the environment