We have solar cells and a wind generator on the Sissi to generate electricity. We use 120 Ah every day when sailing, which somehow want to be generated again. On bad days we use the battery banks with 540 Ah capacity, but we want to refill them on good days. Otherwise the energy balance is wrong and the refrigerator goes out.
If we want to produce half of the 120 Ah from the sun and half from the wind, we need 60 Ah from the solar cells in the 12 bright hours of the day and 60 Ah from the wind generator in 24 hours. That makes the charging current of 5 A for the solar cells and 2.5 A for the wind generator, because he has twice as much time for his workload.
After studying relevant websites, we decided on a Superwind 350. There are stronger propellers and there are cheaper propellers. The reviews of other sailors have brought us to this device.
After several days of sailing across the North Sea and Biscay, the calculation seems to work. However, we are not allowed to use the electric autopilot, because it needs another 60 Ah. The wind vane control must do that. The batteries are almost always filled to 100% when sailing.
From about 12 knots of wind on the wind display, the wind generator starts charging. Then it charges with 2 to 3 A. The highest value that we have read so far from the battery monitor was 18 A. However, we also had a brutal course on the wind with wind force six to seven. However, when the wind drops below 12 knots and the sun hides behind the clouds, the batteries slowly empty.
The short film was made in Vigo. First the generator is braked with the electric brake, it turns only very slowly. Then the brake is released.
The switch for the electric brake is very practical. We have already seen other boat crews catching their wind generator in the harbor and turning it out of the wind with a rope and securing it. We simply set the switch to “Off”.
If the battery is full, the excess energy is heated in a resistor. This way the generator does not heat the batteries. On such windy days, we have already considered running the vacuum cleaner on inverters so that we can also consume the wind power. Optionally, we could operate an electric fan heater via the inverter - but that is no fun at 25 ° C outside temperature.