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Off-grid solar system for an office
A complete off-grid solar system for an office — no grid connection, sized to run a full working day on its own. Built around the Felicity MJS IVBM10048P1G1, with 2 × FLS48100SG2 and 17 × GK-1-72HTBD-580M.
That's a 10 kW inverter, 73.7 kWh of battery storage and 17 panels working together.
How we sized it
This system is built to handle 9.2 kW at once. Appliances like compressors and pumps briefly draw far more than their running power the moment they switch on — so we size for that peak moment, not just the average, which is what keeps the inverter from tripping when a few things start up together. And the 10 kW inverter carries comfortable headroom above that peak.
Day to day, that's about 40.4 kWh of use — the number the Felicity MJS bundle above is built to cover.
With no grid to lean on at all, that day (plus a cloudy-day reserve) needs about 40.4 kWh; the 2 × FLS48100SG2 we've picked gives you 73.7 kWh installed.
The array works out to 9.5 kWp — 17 panels of the GK-1-72HTBD-580M across roughly 44 m² of roof — assuming the strong, fairly steady sunshine typical of our main markets (about 5.7 peak sun hours a day). Your own roof may do a little better or worse depending on shading and the season.
Frequently asked questions
What can this system power?
A working office, three ACs and four computers through the day. It's sized to handle up to 9.2 kW at once — enough for whichever appliance switches on hardest.
How long does the backup last?
This system is sized to store about 40.4 kWh — a full day of use plus a cloudy-day reserve — because there's no grid to fall back on.
How many solar panels does it need?
17 panels, about 9.5 kWp, filling roughly 44 m² of roof.
Can I expand this system later?
Yes — inverters, batteries and panel arrays in this range are modular, so you can add more battery modules or extra panels later, starting from this 9.2 kW / 9.5 kWp baseline.