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Offgrid inverters either get the power from the batteries/charge controllers or they get the power from the grid (usually to charge the batteries - they are cal

by cfn 5y ago

Offgrid inverters either get the power from the batteries/charge controllers or they get the power from the grid (usually to charge the batteries - they are called charger-inverters, look at the Outback VFX series for an example). This means that either you get the unstable grid power or you get the stable solar/battery power. Maybe there are inverters that somehow compensate and correct the power but I doubt it since they would be fighting the rest of the grid. I would suggest that you add solar with a small battery bank and use the grid for overnight and for dark day charging. This way you have the best of both worlds as you only need a big battery bank if you need a lot of power when there is no sun. P.S. Start with a 48 system since you are going for so much solar power. It is safer and cheaper in the long run.

rklaehn 5y ago
Maybe the all in one system is not good in that case. I was hoping that since they already have the AC-DC inverter built in they could also do voltage stabilization. Maybe charge the batteries from either the grid or the PV panels, and always run the house off the batteries via a separate inverter. That way, you got the inefficiency of AC->DC->AC but always have stable voltage. In the long run I want this to be mostly off grid anyway, with the grid as just an emergency option...
- cfn 5y ago
  Yes, that is a good idea. Get a separate charger and always run the house from the isolated side. This will be more expensive as a good inverter/charger runs in the 1k-2k Euros area and you would need two (unless you find a suitable battery charger which is not very easy). I lived offgrid for nearly a decade and built myself three different solar systems. I started with a small all in one and found out that they are limiting when you want to expand since you usually cannot add more charge controllers and/or panels (which are the easiest way to expand a system). I ended up giving it away and building the others from separate systems. My biggest mistake was starting with 24 volts instead of 48 volts. It is cheaper but it gets a bit dangerous as you step up the power usage and there aren't many options for breakers and such.

by cfn 5y ago

rklaehn 5y ago

Maybe the all in one system is not good in that case. I was hoping that since they already have the AC-DC inverter built in they could also do voltage stabilization. Maybe charge the batteries from either the grid or the PV panels, and always run the house off the batteries via a separate inverter. That way, you got the inefficiency of AC->DC->AC but always have stable voltage. In the long run I want this to be mostly off grid anyway, with the grid as just an emergency option...

cfn 5y ago
Yes, that is a good idea. Get a separate charger and always run the house from the isolated side. This will be more expensive as a good inverter/charger runs in the 1k-2k Euros area and you would need two (unless you find a suitable battery charger which is not very easy). I lived offgrid for nearly a decade and built myself three different solar systems. I started with a small all in one and found out that they are limiting when you want to expand since you usually cannot add more charge controllers and/or panels (which are the easiest way to expand a system). I ended up giving it away and building the others from separate systems. My biggest mistake was starting with 24 volts instead of 48 volts. It is cheaper but it gets a bit dangerous as you step up the power usage and there aren't many options for breakers and such.