#1 variable :offgrid or ongrid? a real biggie here!
#2 what is your average loads in kwatts per day?
#3 what is your peak load during the day?
#4 what loads can be scheduled?
#5 what is your average charging capability ?
#6 what is your peak charging capability?
#7 what are you using to recharge with, if solar how many hours per day? how many days of sunshine per week? etc
and there are more ...
the more of these that you can accurately answer, the more information you can plug into established equations, which will then give you a group of answers, like
1.what size bank you will need
2. what will that banks first cost be
3. what will the cost per kw/hr be as related to the battery
4. what will i get in useful kw/hrs per day out of the batteries
5. what will i have to provide to the battery bank each day, and where
will it be coming from.
6. how long should i expect them to last?
and more questions will come up and you will have the information to answer them fairly accurately.
otherwise it is a crap shoot! and just as gambling you can step up to the table and loose your lunch money.
bob g
I'm doing this off-grid,
Here's some appliances I expect to be using:
Frost-free refrigerator: 170 kwh
Frost-free freezer: 188 kwh
Lighting for 4-5 rooms: 50 kwh
3-4 water pumps for solar system - 1A/12vdc each using 48vdc->12vdc converter
other misc appliances (coffee maker, computer, etc)
I'm gonna say about 500 kwh total?
I'm using (30) flexible solar panels: UNI-PVL 128
I was figuring on buying (32) of the 6v GC2 batteries from Sams Club:
Minutes at 75 AMPS: 107
20 AMP Hour Capacity: 208
4 parallel banks of 8 series
I'm attaching a pdf of the results from the classic sizing tool at Midnite Solar
The avg days of sunshine for my location is around 200/year (WY)
There's plenty of wind but a lot of it is very windy so I'm not sure about using wind.
I also have a 1000 kW gas powered generator which I could use in emergencies (I'd have to be there to crank it up).