In 2019 I was asked to estimate how big a certain electrical battery should be, given:
- energy demand
- energy generation (PV-panels)
- percentage of self sufficiency
- (100% = all used energy is generated on your own
- 0% = all used energy is delivered by the Grid)
With this information ,climate data and some assumptions, a battery simulator was created. The simulator will simulate one year and change battery parameters for each following simulation. The energy balance ,percentage of self sufficiency and battery size are the most important results.
The simulations below are all made for a district of (80? check) houses. 60 PV-panels are installed in this district.
Residuals, Best:1991518.48459, New:2041143.27939
Total Energy:29953.692 kWh
Grey Energy:19603.7410788 kWh
Self sufficiency: 34.5531726814 %
Residuals, Best:1971168.82445, New:2241909.47303
Total Energy:29953.692 kWh
Grey Energy:19234.2770753 kWh
Self sufficiency: 35.7866233142 %
The two simulations above (for 20 kWh and 160 kWh battery) clearly show that there is hardly any difference in self-sufficiency (1.2%). Compared to the higher investment, this is not worth it. In cold climates, the energy generation in the winter is so low compared to the energy demand that the battery will drain in less then a week.
In the jupyter notebook file which is shown below, all details about the simulation are given. the 20 and 160 kWh battery case above are copied from this file.