Home solar project outline

Have you played with NREL's PVWatts? This calculator is local-climate-aware, accounting for typical losses from cloud cover and other weather at your particular location. Putting in for a 2kW-dc system at Huntsville with default parameters, I get this result, just half of what I'd need for my smaller all-electric house, after major energy conservation work, and without an EV:


Your winter minimum is 55% of your summer maximum, not too shaby. In my climate zone, winter minimum is only 18% of summer max, making the winter capacity for off-grid too expensive, so I must go grid-tied. If I did have enough winter capacity to go off-grid, I'd be foregoing a large amount of potential revenue from the summer surplus. Surplus that ought to go help offset someone else's inability to install solar.

Island operation is now possible on modern grid-tie systems with battery storage and appropriate controller (Powerwall and others) and system architecture. My current microinverters were not set up for this mode, but with new firmware and $$$ for batteries, controller, and service entrance re-configuration, could now do so. With you already having a backup generator with transfer switch, you might be part way there already.

My system has 7kW-dc, 6kW-ac, and produces just over 6000 kWh/year. NREL thinks I should get 7,600, but doesn't account for the shadowing of a neighboring wall of trees. If you do have tree shadow impairments, then I do agree with using micro-inverters instead of a string inverter.

==============
P.S. You mentioned hot water. If electric, do you have a heat pump water heater already? If not, this would be a good upgrade independent of any solar system.