We are thinking about installing a solar system on our flat roof or carport to save the electricity costs of 70 euros. After all, electricity will not get cheaper.. we wouldn’t have to finance the solar system.
We also considered it - but have temporarily discarded the idea. During various research and conversations, it repeatedly became clear that only about 20 - 30 % of one’s own electricity consumption can be saved with solar. The 30 % would be reached, for example, if the washing machine / dryer / dishwasher could be programmed to run during good sunlight (highest energy production). Reasons for this relatively low share of self-consumption: - permanent consumers (must run at all times of day and night) - e.g. refrigerator, freezer chest, etc. - increased consumption when it is dark - during the day you are at work and towards evening (with low or no electricity production) various consumers are switched on (stove, TV, lights, etc.) - in the dark and cold season, electricity consumption of heat pumps increases exponentially (in summer, less heating is needed) - at the same time, electricity production decreases sharply during the dark season (a former colleague of mine has photovoltaic on his roof - result 2012/2013: in winter he produced as much electricity in one month as he did in two days in summer) Self-production is most worthwhile if combined with a storage solution. These are still very expensive at the moment (around 10,000 euros), so that despite government subsidies, it is hard to make economic sense. For the future, however, this would be an option that we are keeping an eye on.