The cost of electricity is increasing. One kilowatt-hour of green electricity from the grid currently costs around 30 euro cents. If you generate it yourself with the help of a photovoltaic system, you pay approximately twelve euro cents for it. However, if you feed this into the grid, you receive from the energy supplier only between 5.94 and 8.64 euro cents per kilowatt-hour as remuneration.
You don't have to take long calculations: only those who use as much solar power as possible will get their money's worth. And if you can store the electricity in a solar battery for the dark hours, you are well on the way to becoming self-sufficient when it comes to energy.
And more and more homeowners seem to be concluding. Not only do you mount a photovoltaic (PV) system on the roof, you also put a home energy storage system in the basement, the garage - or wherever it fits. According to a survey by the Bonn market research institute EuPD Research in the first half of 2020, around 63,000 new small-scale PV systems with a peak output of up to 10 kilowatts were installed in Germany. That is an increase of 56 percent compared to the previous year. The home energy storage business grew even faster, by 59 percent: 46,000 systems were installed in the first half of 2020 - as many as in the entire previous year. For the year as a whole, EuPD is now forecasting a total market of around 88,000 systems. That would still be an increase of 35 percent compared to the previous year. EuPD asked component manufacturers and installation companies, but also end customers, about this.
In this context, Sonnen (Germany) consolidated its top position and increased its market share to 21 percent. Behind them are the Chinese manufacturer BYD and two other German manufacturers with E3 / DC and Senec.
Sonnen manager Mathias Bloch sees the reasons for the widening gap between the feed-in tariff and the consumer price for green electricity. "It is more the case that renewable energies are becoming more and more relevant for many people in everyday life and that they have arrived on the market, that energy storage systems are mature, sensible and affordable for many people. It is often the case with new technologies that they have broadly adopted from a certain point onwards. "
Another driver is the growing spread of electric cars: "This is the ideal addition to the eco-system ." For this, it is necessary to buffer the electricity generated during the day, ideally, with a home energy storage system with the appropriate capacity. The top model from Sonnen can store up to 55 kWh of electricity - and that for up to 20 years. Bloch: "The lithium iron phosphate technology has proven to be very durable and safe."
Simpler versions save between 5.5 and 27.5 kWh costs between just under 8,000 and around 36,000 euros. Like the PV modules, the energy storage systems have also become significantly more powerful in recent years. For example, the Tesla "Powerwall" with 13.5 kWh, which many Tesla drivers covet (but not yet available in this country), is only available at around 8800 euros in the price list - which is why the manufacturer offers homeowners up to 10 battery storage devices at once to order. Then the battery of a Tesla Model X could be fully recharged overnight. Not for free, but over the years, significantly cheaper than on the public Supercharger.