A couple of years ago, a few ingenious engineers came up with a stunning solution to the cascading effect of a malfunctioning solar panel on it’s string in a photovoltaic installation. „If every single panel had the capacity to produce alternating current on it’s own, it would not affect the functionality of the others in case of a malfuction.“ they argued. And thus the micro-inverter was concieved. It converts the direct current produced by a single solar panel into alternating current with grid compatible voltage. „Wait a moment!“ some rebellious photovoltaics-enthusiasts were pondering soon after. „If it’s grid compatible, it is also usable in a home circuit!“ And they quickly screwed a power plug onto the output cable of the inverter and plugged it into a common power socket in their home. That was the birthing hour of the device now known in Germany as a „Balcony Powerplant“.
In Germany this technology was first met with great concerns by grid providers and regulatory authorities. This was mostly due to uncertainties and a lack of reliable standards. But in 2017 and 2018 respectively, new regulations were issued, setting the needed standards and limitations to which all devices would have to adhere: The inverter now has to deactivate if voltage, frequency or impedance is not within parameter, the plug has to be specially suited and the use in home circuits is limited to a maximum of 600 Watts of inverter output. In addition, every device has to be registered with the grid provider as well as in a national registry.
With these new cornerstones in place, an open and lively market started to flourish, new innovations and new fields of usage could be established and growth became exponential. Even though few aspects like the form of registration with the over 800 german grid providers or the exact kind of plug that should be used are still debated, the technology is already used and distributed more and more widely.
The Berlin-based company EmpowerSource is a driving force behind this development, participating in the regulatory process, urging grid providers to update their processes, providing transparency, information and help to customers as well as regulatory organisations.