Welcome to the forums!
The place to start is an
energy audit. After that I'd suggest a hybrid inverter, possibly the Skybox? Ideally a day's worth of battery and possibly a generator to recharge for day 2 if there isn't enough solar. If you can get natural gas where you live (and it doesn't freeze like Texas), go that way as then you don't have to haul fuel. Or go propane, a few 20 pound tanks (spares for your grill), should last a while and unlike gasoline never goes bad.
... I have calculated the system would need to accommodate 7000 watt hours per day with a peak load of 810 watts.
Assuming you've completed the energy audit and are happy with the numbers, you'll need to know the maximum inrush current for your AC. The inverter will need to supply the inrush or you'll need a
softstarter. But check, I believe Midea makes minisplits, so if yours has an inverter the surge might be very small. Also beware that if the Air Conditioner is 120V and you have a 240V inverter, the inverter may only put 1/2 the surge capability on each phase.
You didn't say, but let's assume that 7000w/d calculated is AC power. If the inverter is 94% efficient, the batteries 96% efficient, and the MPPT 98% efficient, then the DC power needed is 7000 W/d AC / .94 / .96 /.98 = ~8000 W/d Solar DC.
Example math:
We'll assume you're optimized for the whole year since Florida has great net metering agreement. A net metering agreement will let you sell excess power to the grid for credit so it's the best bang for the buck.
From the insolation data to the right, 4.51 is the yearly minimum. You want 7000 watt hours per day, so 7000 / 4.51 = 1552 watt array (round up) or about 5x 310 Watt panels.
In April, those same panels would make 6.11 x 1552 = 9,480 wh/d. With a net-metering agreement, you can bank those credits -- which means you don't really need a 1552 watt array. You can split the difference somewhere in the middle.
So how many panels do you actually need? That's up to you, but at least you have some math to play around with it. |
For more accurate power generation look at SAM or PVWatts. |
One last bit on that... those numbers are the
average. During a hurricane outage you're guaranteed to be overcast and rainy so you won't be seeing anywhere near as much power. Typically folks will have a one or more days of battery to carry them through, then possibly a generator for extended bad conditions.
How many batteries?
Let's assume you want one day of batteries and will use a generator to augment the solar recharging beyond that, so you need 8000 wh of DC. You don't want to discharge the battery to deeply, otherwise it can impact the lifespan. For LiFePO4, you can typically go with a depth of discharge around 80%, so 8000 / .8 = 10 kWh batteries. Kilovault sells batteries for about $1/W. The Tesla powerwall is a turnkey solution for a bit more. If you're a DIYer check out Will's videos for how to build one. Check out the battery FAQ too, these numbers are representative of LiFePO4, if you use lead acid there are a number of other factors to consider.
If you're only using your batteries for emergency purposes, you might not want LeFePO4. LiFePO4 doesn't like to be fully charged all the time, lead acid does. Again, look through the Battery FAQ and this
thread, ask any questions you have. Finally, check out the
FAQ index, lots of examples that will answer a lot of questions.
Hope that helps and hope to hear a lot more from you!