Solar power has been around for a long time. In the past, it was the maintenance of research projects and municipal installations on a large scale. Eventually, as the technology grew cheaper, rooftop solar arrived, and cash-strapped homeowners rushed to install panels on their homes to reduce their energy bills and make money in some cases.
Those who were in apartments or rented places were left out of the solar system. That was, until the solar porch. Popular in Germany, but little known around the world, this concept has brought home energy production to a bigger market than ever before.
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Photovoltaic solar panels were very expensive to make, back in the day. This has made it difficult for solar energy to compete with conventional energy sources such as fossil fuels. High installation costs and limited energy output make the business case difficult, even if the energy from the sun itself were free. However, as the demand for clean energy sources grew over the years, the production of solar panels grew accordingly. Economies of scale did their thing, and the panels grew cheap enough for people to consider installing them in their homes. This has led to the widespread adoption of rooftop solar, with installations typically ranging from 5 kW to 10 kW in size with inverter hardware to allow safe and controlled feeding of energy into the grid.
The problem with rooftop solar is that not everyone owns their own roof. Many people around the world live in houses, or rent, and are not in a position to permanently change their home. These groups are largely left out of the solar revolution. That was, until solar panels grew cheaper and electric bills grew enough that even small installations started to make financial sense.
In Germany in particular, small solar installations have become very popular, and the country has become a so-called “balcony” solar installation hotbed. This includes a simple setup of one or two solar panels that are designed to be easily installed on a porch or other outdoor area of the house, rather than permanently installed on the roof.
They come with small inverters to convert the DC output of the solar panels into AC power, plugging directly into an existing home power socket. This do-it-yourself method eliminates the need to hire an electrician, improving system accessibility. The inverters used with these systems include anti-islanding protection so that the solar system does not have power in any regions if the grid is de-energized for operation or maintenance.
Balcony solar has some limitations compared to rooftop installations. In general, the installation angles are not perfect for making the sun available. There are also limitations to how much power you can get from such a system. The first German regulations for “balkonkraftwerk” systems stated that the power supply should be limited to 600 watts to avoid possible problems with house cables and sockets that were never designed to supply solar power.
The revised rules allow up to 800 watts of feed-in, with the additional rule that installed panels do not exceed a maximum output of 2000 watts. It may sound like a contradiction, but it is possible to use more power from the panels to charge the battery when the output exceeds the limit of 800 watts. Having large panels with high output is useful, too, if the sun is not too bright. A 2000 watt peak panel setup will output 800 watts or more often than a set of panels that only deliver 800 watts at peak conditions.
Despite the restrictions, or perhaps because of them, it’s a cinch to find yourself traveling with the sun in Germany. Just go to your local big box store, buy a kit, and hang it on the side of your house. Once you plug it into the wall, you’re pretty much done. Most kits come with some sort of system monitoring app so you can keep an eye on how much your panels are producing. Ease of access has led to increased installation, with more than 1 million rooftop solar systems operating in the country.
Until now, balcony solar has always been a German thing. However, some parts of the world continue. Some European countries such as Spain, France and Belgium are already on board. In the United States, the state of Utah has already approved a draft for solar porch installations, with Virginia following close behind. The key has been devising special methods to allow easy, cheap DIY installation of small solar systems.
In general, installing rooftop solar in most states requires signing an agreement with a local utility regarding the supply of energy to the grid, and hiring professional contractors for installation. This adds a large amount of cost that a small solar system may not recover in a timely manner. By removing these barriers to setting up small-scale plug-ins, they are effective and accessible to the wider community.
Balcony solar is unlikely to be an immediate game changer that shakes up the power grid. Most installations are low power. Their juice is too much to use for the fridge and one or two TVs, and few make a significant contribution to feeding the wider grid. However, their popularity in Europe shows that there is a great desire among the general public to ride the solar train in any way. At the very least, balcony solar is a great business opportunity and bringing sustainability to more corners of urban and suburban areas than ever before.
Featured image: “Sogenanntes Balkonkraftwerk” by [Triplec85]
