Manufacturers say that installing a couple of 300-watt panels will give a saving of up to 30% on a typical household’s electricity bill. With an outlay of €400-800 and with no installation cost, the panels could pay for themselves within six years.
In Spain, where two thirds of the population live in apartments and installing panels on the roof requires the consent of a majority of the building’s residents, this DIY technology has obvious advantages.
With solar balconies, no such consent is required unless the facade is listed as of historic interest or there is a specific prohibition from the residents’ association or the local authority. Furthermore, as long as the installation does not exceed 800 watts it doesn’t require certification, which can cost from €100 to €400, depending on the area.
As with all solar power systems, balcony power only works in daylight and a battery storage system can add at least €1,000 to the installation cost.
Vernetta says the vertical surface area of cities is far greater than that of the roofs and that, in Spain, balcony panels benefit more than roof panels from the low winter sun.
Cities such as Helsinki are already experimenting with buildings with solar panel cladding.
The system can only feed into your house line if there is an external 230V 50Hz power net working. The moment the net goes down there will be no power from your micro inverter to your house. It requires power to work and a stable 50 Hz similar to most bigger inverters.
If you combine a power station (battery) with the inverter, this battery might give you a 230V outlet with stable 50 Hz. But this is not the one you should plug back into your house (would require an unsafe cable).
Overall, lots of fear and wrong information in this thread about safety. There is a DIN norm for all of this and the current 800W limit exists to keep your power line from melting in the walls in the most extreme cases.