Increasing PV self-consumption with heat pumps – sense or non-sense of additional electric heaters

Hot water and space heating are increasingly being provided by photovoltaics in combination with heat pumps.
In most cases, end user purchase tariffs for electric energy are significantly higher than feed-in tariffs for photovoltaic electricity. Therefore, increasing self-consumption of locally produced photovoltaic electricity makes economically sense, if a corresponding reduction of electric energy consumed from the grid can be achieved. At the same time, the self-consumption measures must not lead to a too high increase in system energy
consumption, which also causes a strong reduction of PV feed-in. In this contribution it is shown that the optimization of thermal storage management by the heat pump is advantageous, while the use of electric heaters in order to heat the storage further when the heat pump has reached its maximum supply temperature generally
leads not only to energetic inefficiency, but also to a financial loss for the end user or owner of the system