Power outage in Münsterland

Intense snowfall broke the high voltage pylons ans with this the power supply. for several days. What would have brought a photovoltaic in this situation.

Grid connected PV is no emergency power supply

A grid connected photovoltaic equipment delivers only power when the grid is on. When a service technican switches off, he depends on, that the grid is really switched off. It has to be impossible, that a photovoltaic delivers power to the wire just under repair.

So a photovoltaic equipment has to be special designed to be also an emergency power supply. An example for this was on the Intersolar fair zu sehen

Electic power failure in spite of own photovoltaic equipment
	Normally a net-coupled photovoltaic equipment switches off immediately if the net has no tension. Protection for electrical engineers maybe just repairing the grid.

Design of the memergency power supply

After the photovoltaic and a equipment for emergency power supply, the next question is the size. To cook electric after a power failure because of a snow strom would be a big luxury. With the question what functions should be supported during a power failure comes the question to switch off big power users, to preserve only basic comfort for a longer power failure.

An other reason for a house control system. Power failure on a sunny day, the photovoltaic delivers 8 kW, no problem for electric cooking. Same situation on a cloudy December day, the electric cooker is switched off by the house controll system.