Thx guys, I'm not looking for a quick simple fix that is costly. Looking more for efficiency. What would something like a 7.5kW Generac PowerPact
I would have my Sol Ark 15k auto trigger the start of the generator when the battery is low.
The Sol Ark would be programmed to draw the maximum power efficiency amount (30 - 50 amps.. I'd need to know exactly what).
The sol ark would apply that power to loads first, the charger second. After batteries reach a predefined level it would be turned off by the sol ark.
Cost per therm here is $0.5597
I will have about 50 panels.
My plan is to start with grid tie net meter 1 month billing. Time of use is 2 rates, 7 AM to 7 PM $0.18, $0.08 after hours.
My sol ark will switch to battery primary at 7 AM to avoid the $0.18.
Any solar created goes to loads, then battery, then grid.
To pay for a $2000 generator over a 25 year period if it is just used for overage, if it produced power at $0.08 it would only need to produce 66 kwh per month.
That's why I'm asking about generator efficiency.
I understand most people run generators and do not draw the load the generator can produce resulting in a huge amount of waste. Since I would only run the generator when I can draw all the power into the battery my efficiency would be higher. How high? That is the question.