Interesting video. Permit me a few observations. Your battery bank is large enough to need a dsulfator. The video movement was rapid enough I could not see if you had one installed. The DC charging is better than average but your amps charge rate is too low to prevent some sulfation. It must be at least 10% of the storage capacity to be truly effective. The alternator you are using is internally regulated as a fixed voltage. What you really neeed is a constant current type. It will speed up the charging by 20%
I recommend a leece Neville 160 Amp model like the big trucks use. L-N have the regulator mounted on the exterior of the case and they have a constant current model(or used to)often used for fire truck aand ambulance work.
Victron makes a charger that can utilize a wide ranging input right down to
DC which would go nicely with yor 220V generator power head. It is not going to be as finiky about speed regulation of the driving motor. Then you simply pull whatever AC voltage from your battery bank via the inverter.
If you are truly interested I know where you can get a 300 amp alternator for fast charging the battery bank and save lots of fuel charging.
Your ground mounted methane digestter is going to run too cool. There are two types of bactereia. One like a 95F temp while the other lives at 150F.
Both types fail to be fully active below their optimum temp. With youer tank set into the ground it will not reach optimum temp for full methane production. Output will be disappointing. I am designing in a heat exchanger to help regulate tank temp. Either hot water in winter or cooling water in summer as needed. With only one large hatch you are going to be stuck with batch production. That size tank is going to have frequent shut downs to reload. Look into movaable plug designs for greater convenience as well as production output.
Your set up is one of the best I have seen so far.
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