June 24, 2021
◼ 5 steps to higher self-consumption
Self-consumption or self-use means consuming the solar electricity produced at the place of generation. This saves costs and relieves the strain on the grid. 5 steps for this!
Permitted in Switzerland since 2014, possible in Germany since the new EEG even above 10 kWp without additional "solar tax": self-consumption of solar electricity from one's own photovoltaic system is increasingly in focus. Increased self-consumption minimises voltage fluctuations in the public grid and saves costs. Because feeding electricity into the grid for 10 cents per kilowatt hour, as is the case in Germany, and then buying it back for 30 cents per kilowatt hour in the evening is not worth it.
But how can self-consumption be easily increased? 5 more or less straightforward ways to become a self-consumption professional!
Step 1: Adjust the system output
If you do not yet have a photovoltaic system, it is important to define the system output in relation to electricity consumption or possible future consumers before installation. However, a system that is (still) too large is not a disaster! It opens up further possibilities for using the photovoltaic electricity produced within your own four walls.
The orientation can also be decisive for new planning or expansion. Check the east-west orientation of the system, because although this has somewhat lower yields than a south-facing system, it produces higher yields in the mornings and evenings that can be consumed directly.
The important thing here is to make the roof as full as possible. Each kWp becomes significantly cheaper, which has an even more positive effect on the electricity production costs as well as the price of the system. The focus is on consuming one's own photovoltaic electricity in the house instead of feeding it into the grid.
Step 2: Operate household appliances with solar power
Switching on larger consumers of electrical energy, such as the dishwasher, the washing machine or the dryer, when the sun is shining and cheap and environmentally friendly energy is available also saves costs (but is rather negligible compared to the energy-intensive provision of hot water). Display solutions that visualise the current surplus can be helpful. Our compatible partners offer many solutions for this, but our cloud my-PV.LIVE also visualises the surpluses. However, the self-consumption of a system with 5 kWp, for example, is only about 30 % of your electricity generation.
Step 3: Hot water through solar power
To heat one litre of water by 1 degree, an energy quantity of 1.16 Wh is required. With an average daily hot water demand of 50 litres per person, this means an energy quantity of 2.3 kWh (without storage tank and pipe losses).
Ergo: Heating the water for consumption requires a lot of energy. A huge potential to increase self-use. With a 5 kWp system, this means that up to 70 % of one's own solar electricity can be consumed in the house. It is important to have an intelligent distribution centre: Our products are continuously and intelligently adjustable and, depending on the yield from the photovoltaic system, use the available surplus to heat the hot water. This is possible as an off-grid DC solution with the ELWA, as a version coupled to the public grid with the AC ELWA-E or with the AC•THOR or AC•THOR 9s.
Step 4: Heating with solar electricity
In well-insulated houses and flats (heating requirement below 50 kWh/m²a), which are now becoming standard, one's own photovoltaic electricity can also be used as a source for heating. A solar-electric heating system, not the old night storage heater, saves operating costs (49 % cheaper than a heat pump!) (German https://www.derinstallateur.at/singleview/article/49-prozent-energiekosten-sparen!) and can be an alternative, especially in the case of renovation. Electric underfloor heating, infrared panels or a combination of both also create cosy and comfortable warmth. And self-consumption increases!
Step 5: A possible e-car
Sector coupling, as the networking of the sectors of the energy industry is called, is completed by the use of one's own photovoltaic electricity for charging the electric car. With regard to large photovoltaic systems, this creates an enormous increase in self-consumption. And the electricity is also produced in an extremely environmentally friendly way and costs a lot less than the purchased electricity from the public grid.