After my first thoughts and research on YT, I quickly came across the site of the European Commission and PVGIS. With this tool you can simulate your theoretical yield.
I would like to present my results here:
- Performance of grid-connected PV
Simulation outputs
Slope angle: 65 °
Azimuth angle: -50 °
Yearly PV energy production: 721.24 kWh
Yearly in-plane irradiation: 1076.2 kWh/m²
Year-to-year variability: 44.92 kWh
Changes in output due to:
Angle of incidence: -3.11 %
Spectral effects: 1.89 %
Temperature and low irradiance: -5.71 %
Total loss: -16.23 %The basic settings I have assumed are:
Installed 820 Wp
System loss of 10%
The simulation results in a potential energy amount of 721 kWh per year. Which, at an electricity price of
0.33 €/kWh, this corresponds to a saving of 237.93 €. If I now assume a self-consumption of 90%, it is still €214.
Monthly energy output from fix-angle PV system.
Here you can see that even in good months, an average of 3 kWh per day is not achieved. For example, in July with 87.3 kWh/month and 31 days, the result is only 2.8 kWh per day. Since these are average values, it can of course still come to more than 3 kWh/day on some days in summer and less on others (rainy days).
- Power production estimate for off-grid PV
The simulation of the off-grid PV system is actually not correct for my case but if I only want to see the approximate expected amount of energy per day, then this can be created as follows.
I enter 820W as the PV power and then add 1 Wh of daily consumption and 1 Wh of battery capacity.
What I can expect is a list of the energy not needed per day. That is, what I can generate on average on one day of the respective month. - Summary
As you can see, after the first observation, the yield is significantly less than assumed with 4 kWh per day. Of course, this was only a mind game and the simulation should be much more reliable. So with my design of the system with 820Wp panels (2 x 410 Watt) and a VDE-compliant inverter with 600W, I get a yield of approx. 2500 W/day in the summer months. Which, however, will drop to 570 W/day in the winter months.
As a consolation, I can assume a fairly high self-consumption rate, so that, as shown in point 1, I can expect a revenue of about €214 per year.
