What is the longest outage time that you would design to sustain? My concern here is that the cost/benefit ratio not may work. You need to determine how much battery capacity you would need to sustain your max outage period. Then work the umbers from there.
You may find out that in order to see the cost benefit that you need to install a full blown solar system, with net-metering and solar tax credits and incentives.
Based on some of the initial replies here and the issue of providing power at 240v through an interlock, I assumed this idea was dead in the water.. But I’ll add some details nonetheless—
If I could make this happen (utilize the interlock with solar/batteries, that is), I would like to treat this as an off-grid scenario, so the plan would be to be able to sustain it forever (barring equipment failures).
I’m definitely not looking to go “all in” on a complete solar build or anything that competes with that price range.
I feel like what I’m looking for is quite simple in features and low in price in comparison to a complete system.
I am talking about connecting a budget inverter, simple performance monitoring, a battery and a few panels (or, an all-in-one unit + panels). Nothing fancy. Just needs to be compatibility with the inlet box I have listed in the first post.
The goal would be, when I manually switch back to grid power, the batteries would have no load and would continue to recharge via solar.
This is an extremely low power requirement to cover “critical needs only”. By my estimate it’s around 5k Wh/Day (150 Kwh/Month) on the low end, and 10 Wh/Day (300 Kwh/Month) on the high end.
For comparison, a Goal Zero Yeti 3000X has a standard battery capacity of 3032Wh which may be sufficient to meet my low end once solar charging is factored in. Or I would think a few standard 100 Ah 12v LiFePO4 batteries would be sufficient.
So what I’m looking for is an all-in-one unit or a DIY build that can handle 120v loads and one 240v load (water pump), and does not break the bank.
If I could power the 240v without having to buy multiple all-in-one units, or adding a sub panel, or other costly methods, etc, I would have done that already. I am trying to avoid that.
I feel like what I’m asking for is achievable with low effort and low cost, and I also feel that one of Will’s budget options that fit the specs could work here. BUT, the issue from what I’ve gathered in this thread, is properly and safely powering both 120v & 240v via the interlock. Everything else that is ‘critical needs only’ is 120v.