More and more people want to invest in solar power systems and battery storage systems. However, according to a German consumer organization, there are several myths that can lead to customer disappointment.
The demand for household rooftop solar systems and household batteries continues to grow. In order to meet the expectations of homeowners, the Verbraucherzentrale NRW – the German consumer association – tries to clarify false expectations about solar installations that may disappoint consumers.
“It is important to be aware of the personal goals of using solar electricity and then find out about them. In this way, disappointments can be avoided and solar electricity can be used really efficiently,” says Sören Demandt, analyst of the transition to digital energy at Verbraucherzentrale NRW.
The first misconception is to promise people that they can become self-sufficient with solar and storage systems. This is not the case, as solar power systems and home storage solutions can only cover a certain portion of a household’s annual electricity supply.
The achievable self-sufficiency rate is 25-90% depending on the level of power consumption and whether storage is installed. Especially in the winter months, the amount of solar electricity produced is not nearly enough, so grid electricity has to be bought, Demandt said. Complete self-sufficiency can only be achieved with seasonal additional storage, such as hydrogen.
“However, it is technically complex and hardly makes economic sense for a residential unit,” Demandt said.
Another misconception is related to the belief that a solar power system is only profitable in combination with a battery. Some homeowners seem to believe that feeding solar power into the grid is not an economically attractive option.
“The solar system is financially viable, even without storage,” Demandt said. “Whether installing a battery in addition to a solar power system is possible depends on several factors – mainly the home’s consumption profile and electricity costs.”
Homeowners should therefore check their self-consumption without storage. They can compare the higher level of self-consumption through battery storage with actual electricity costs.
Verbraucherzentrale NRW also rejects the idea that south-facing roofs are always better for solar systems than east-west facing roofs. It’s not just about producing as much solar energy as possible, but about producing electricity when it’s needed. On an east-west facing roof, the annual output of the photovoltaic system is only about 80% compared to a south facing roof. However, the yield of solar power systems on east-west facing roofs can be spread over the whole day, as the system still receives a significant amount of sun in the morning and evening.
Many people who do not have a roof for solar installations often consider investing in plug-in solar systems. They can be attached to the balcony or installed in the garden. However, if tenants are hoping to use electricity for household appliances such as coffee makers, they may be disappointed.
“These panels are particularly well-suited to cover the base load of a household,” explained Demandt. “Electricity is used directly – for example, for the telephone, internet router or alarm clock radio.”
If more power is needed, it can be obtained from the grid. This is the case, for example, with a coffee machine, which momentarily requires around 2000 W to heat the water. According to the Verbraucherzentrale NRW, this is not only achieved with solar modules on the balcony.