Off-grid solar and battery sizing for Malabo
A 1 kW array in Malabo produces about 1,320 kWh a year — but that annual figure is not what sizes a system. July is, and in July the same array makes only 2.8 kWh a day, against 4.5 in January.
What do you need?
Battery bank
12.9 kWh
268 Ah at 48V
Solar array
1.47 kW
about 4 panels of 450W
Summer only
0.90 kW
if you only use it January-ish
Sizing by household
Year-round systems in Malabo, three days of autonomy, lithium.
| Use | Per day | Battery | Array | Panels |
|---|---|---|---|---|
| Weekend cabin LED lights, phone charging, a laptop, a small water pump |
1.0 kWh | 4.3 kWh | 0.49 kW | 2 |
| Basic off-grid living The above plus a small fridge and a few hours of television |
3.0 kWh | 12.9 kWh | 1.47 kW | 4 |
| Comfortable off-grid home Full-size fridge-freezer, washing machine, pumps, laptops |
6.0 kWh | 25.7 kWh | 2.94 kW | 7 |
| Everything except heating A normal household load, with heating and cooking on gas or wood |
10.0 kWh | 42.9 kWh | 4.90 kW | 11 |
Why July decides everything
Array needed to cover 3.0 kWh a day, month by month. The tallest bar is the one your system has to survive.
| Month | Yield per kW | Array needed | |
|---|---|---|---|
| January | 4.54 kWh/day | 0.90 kW | |
| February | 4.48 kWh/day | 0.91 kW | |
| March | 3.95 kWh/day | 1.03 kW | |
| April | 3.79 kWh/day | 1.08 kW | |
| May | 3.39 kWh/day | 1.20 kW | |
| June | 2.86 kWh/day | 1.42 kW | |
| July (worst) | 2.77 kWh/day | 1.47 kW | |
| August | 2.91 kWh/day | 1.40 kW | |
| September | 3.07 kWh/day | 1.33 kW | |
| October | 3.39 kWh/day | 1.20 kW | |
| November | 3.85 kWh/day | 1.06 kW | |
| December | 4.44 kWh/day | 0.92 kW |
What the numbers assume
- Battery capacity allows for inverter losses, round-trip efficiency, and a usable depth of discharge — 80% for lithium, 50% for lead-acid. Nameplate capacity is always larger than the energy you can actually use.
- Array size includes a 25% margin over the bare requirement. A system that exactly meets demand on an average day of July never recovers from a run of cloudy ones.
- Yield figures are measured, not modelled — PVGIS satellite and reanalysis data for 2005–2023, at the optimal angle for this location, with 14% system losses already deducted.
Other cities in Equatorial Guinea
Limitations
- No shading. Trees, terrain and buildings are not modelled and can dominate everything here.
- Nothing about heating. Electric heating or cooking multiplies these figures several times over. Off-grid systems almost always use gas or wood for heat.
- Batteries age. Capacity falls over years; installers commonly oversize to allow for it.
- This is an estimate, not a design. A real installation needs a survey, local electrical regulations, and someone accountable for the result.