L R AS Published on Sunday 19 March 2023 - n° 437 - Categories:self-consumption

The false expectations of prosumers

A German consumer association, the Verbraucherzentrale NRW, is working to dispel false expectations about photovoltaic installations that could disappoint prosumers (energy producer-consumers).

The first misconception is to promise people that they can become self-sufficient with a PV system grafted onto a storage system. Photovoltaic systems and domestic storage solutions can only cover a certain proportion of the annual electricity supply of households. The degree of self-sufficiency that can be achieved is between 25% and 90%, depending on the level of electricity consumption and whether a storage system is installed. Especially during the winter months, the amount of solar energy that can be produced is far from sufficient.

Another misconception is the belief that a PV system is only interesting in combination with a battery. A photovoltaic system is financially interesting even without storage.

Another misconception is that south-facing roofs are always more suitable for PV systems than east and west-facing roofs. It is not just a matter of producing as much solar energy as possible, but of producing electricity when it is needed. The annual yield of a photovoltaic system on an east-west facing roof is only about 80% compared to a south facing roof. However, the yield of solar systems installed on east-west facing roofs can be spread over a whole day, as these systems always receive a significant amount of sunlight in the morning and evening.

Finally , plug-in solar systems can be mounted on balconies or installed in gardens. These panels are particularly suitable for covering the basic load of a household. The electricity is used directly, for example for a telephone, internet router or clock radio.

If more energy is needed, it will be supplied from the grid.


PV Magazine of 17 March 2023

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