I am working on plans for a new off-grid home in New Brunswick, Canada. I am trying to sort out the size of my system and I am getting quotes across a pretty big range.
My expected load is 5,500 kWhr/year (about 15kWhr/day) based on the design for the house. Solar potential for my area is shown in this chart:
- 2.4kW panels, 26kWhr batteries
- 8.4kW panels, 65kWhr batteries
- 8.4kW panels, 139kWhr batteries
- 5.4kW panels, batteries TBD
- 7.1kW panels, 118kWhr batteries
From my understanding of the solar potential for my area:
- I will produce 60kWhr per kW of panels installed in worst months
- I need 15kWhr/day * 31 days = 465kWhr for worst months
- Panels should be 465kWhr / 60kWhr/kW = 7.75kW
- If I assume lead acid batteries and two days backup (as was done in my quotes) batteries should be 15kWhr/day * 2days / 30% depth of discharge = 100kWhr
Can anyone sort me out? Do I have an error in my understanding of the system size basics? Why would the quotes I am getting be so different?