In November 2025, Adebayo Olatunji, chairman of a fisherman's cooperative in Epe, Lagos State, Nigeria, contacted us. He was representing 43 fishermen in the village with a request for a completely grid-independent cold storage solution:
The village sits 12 km from the nearest high-voltage line. Mains power is available only 6 hours/day (7 pm to 1 am), and outages occur 2–3 times per week.
Fishermen leave the dock at 4 am and return at 2 pm. Any catch not cooled to 0–4°C within 4 hours shows significant spoilage.
The previous setup — a diesel genset and small freezers — cost $1,800/month in fuel while fish loss still hit 35%.
There is no three-phase power, and the grid extension quote from the Nigerian power utility was ~$65,000 — far out of reach.
Our delivered package: 1 × 12 m³ Flandcold glass door walk-in cooler (chiller range) + 9.6 kWp PV array + 30 kWh LiFePO4 battery + 8 kW hybrid inverter. The June 2026 follow-up gave us 8 months of operating data: fish loss fell from 35% to 4.5%; annual diesel savings hit $18,400; village net income rose by ~$24,000/year.
Case study: Epe fishing village cooperative, Lagos State, Nigeria
Before: diesel genset + 3 small freezers, $1,800/month fuel, 35% fish loss
After: Flandcold 12 m³ walk-in cooler + 9.6 kWp PV + 30 kWh LiFePO4 + 8 kW hybrid inverter
8-month result: fish loss down to 4.5%; diesel savings $18,400/year; village net income +$24,000/year
Reliability: continuous operation through 8 months including rainy season; battery SOC never dropped below 35%
This is a recurring pattern across weak-grid Africa: electricity isn't cheap (Nigeria residential tariff runs $0.08–$0.12/kWh), but outage frequency makes standalone refrigeration impossible. The lesson for any customer facing similar conditions is to spec the cooler and the PV system together, not as separate purchases.
The most common mistake in solar cold-room sizing is to spec the PV system first and then pick the cooler — and discover the PV is undersized. The correct sequence is fix the cooler's daily kWh, then size the PV to match.
Cooler volume | Chiller range (0–4°C), daily kWh | Freezer range (-18 to -22°C), daily kWh |
|---|---|---|
5 m³ | 4–6 kWh | 11–15 kWh |
10 m³ | 8–12 kWh | 20–27 kWh |
15 m³ | 11–16 kWh | 28–38 kWh |
20 m³ | 14–20 kWh | 36–48 kWh |
30 m³ | 20–28 kWh | 52–68 kWh |
Hard numbers behind the table:
Ambient temperature 25–35°C (tropical/subtropical); door events 30–50/day
Glass door walk-in cooler uses 100 mm PU panels (k ≤ 0.024 W/(m·K)), so freezer daily kWh is 30% below industry average
Flandcold ECO+EMM option takes another 35% off (multiply the table by 0.65)
The starting point — and the geographic spread is significant:
Region | Annual PSH (kWh/m²/day) |
|---|---|
Southern Nigeria, Kenya, Equatorial Guinea | 4.5–5.5 |
Saudi Arabia, UAE, Qatar | 5.5–6.5 |
Indonesia, Malaysia, Philippines | 4.0–4.8 |
Vietnam, Thailand, Myanmar | 4.2–5.0 |
Egypt, Morocco, Mauritania | 5.0–6.0 |
Formula: PV capacity (kWp) = cooler daily kWh ÷ local PSH ÷ system factor 0.75 × redundancy 1.3
Back to Epe village: 12 m³ chiller-range cooler, daily kWh ≈ 10; local PSH ≈ 4.8 h; system factor 0.75 (panel degradation, inverter loss, temperature loss); redundancy 1.3 (overcast buffer).
Calc: 10 ÷ 4.8 ÷ 0.75 × 1.3 ≈ 3.6 kWp. We actually deployed 9.6 kWp — because the client required three consecutive overcast days of full off-grid operation, PV capacity had to be scaled ~2.5x to keep the battery charged.
Formula: Battery capacity (kWh) = cooler daily kWh × backup days ÷ DOD
For LiFePO4, DOD = 0.8 (80% safe discharge). Backup-day guidance:
Grid + PV as primary: 1.0–1.5 days
Fully off-grid: 2.0–3.0 days (Epe fishing village sized this way)
Cap at 3.0 days: deeper idle batteries degrade faster without enough cycling
Epe: 10 × 2.5 ÷ 0.8 ≈ 31.25 kWh; actual 30 kWh (leaving SOC headroom for inverter protection).
Inverter hard specs:
Capacity = cooler compressor peak power × 1.5 (startup current factor)
Typical compressor draw on a glass door walk-in: 10 m³ chiller ≈ 1.2 kW; 10 m³ freezer ≈ 2.5 kW
10 m³ chiller inverter ≥ 2 kW; freezer inverter ≥ 4 kW
Must be hybrid inverter: PV + battery + grid/diesel auto-switching
Critical specs: true sine wave output, THD ≤ 3%, soft-start buffer for compressor inrush
Case study: Mathew, dairy cooperative, Nairobi suburbs, Kenya
Need: 15 m³ chiller range, store 5,000 L of fresh milk
Cooler daily kWh: 13 (with ECO+EMM)
PV: 6.5 kWp (PSH 5.2, redundancy 1.3)
Battery: 25 kWh LiFePO4 (2-day backup)
Inverter: 5 kW hybrid
Result: diesel genset fully retired; $720/month diesel saved in 3-month measurement
Case study: Aden fishing port freezer, Yemen
Need: 20 m³ freezer range (-20°C), whole tuna storage
Cooler daily kWh: 40 (with ECO+EMM)
PV: 18 kWp (PSH 5.8, redundancy 1.3)
Battery: 80 kWh (1.5-day backup, smaller to control capex)
Inverter: 15 kW three-phase hybrid
Note: in conflict zones, inverter must be specified with EMP (electromagnetic pulse) filter
Case study: Zanzibar Island cold-drink kiosk, Tanzania
Need: 6 m³ chiller + 4 m³ freezer (small convenience store)
Cooler daily kWh: chiller 4 + freezer 12 = 16 (with ECO+EMM)
PV: 7.5 kWp (PSH 5.0, redundancy 1.3)
Battery: 30 kWh (2-day backup)
Inverter: 6 kW hybrid
Result: 24-hour unreliable island grid → kiosk became the only always-cold beverage outlet on the island
Back to Adebayo's case: if we had used a standard cooler (no ECO+EMM), the 12 m³ chiller would have drawn ~13 kWh/day. PV would need 4.7 kWp and battery 38 kWh — pushing the total project from $28,000 to $36,000. The cooler's energy profile directly determines the PV and battery sizing.
ECO+EMM −35% Smaller PV investment 30 kWh LiFePO4 8 kW hybrid inverter ICOLD cloud 3,600+ service points
✔ ECO+EMM −35%: cuts PV and battery sizing; Epe project saved ~$8,000 in PV hardware
✔ Inverter compressor soft-start: 40% lower inrush current → inverter capacity can be ~1 kW smaller than with a standard compressor
✔ ICOLD cloud monitoring: temperature, compressor runtime, PV yield, SOC all on the cloud; outage alerts arrive before the user does
✔ Four grid-mode presets: fully off-grid / on-grid / on-grid+backup / hybrid-grid+PV — switched with one setting
✔ Global service network: 3,600+ points across Africa, Southeast Asia, Middle East; common spares within 48 hours
Our engineers can take your local PSH data, cooler volume, temperature range, and backup-day requirement and return a complete PV + battery + inverter bill of materials plus a 5-year TCO.
Need a solar cold-room configuration?
Send us your cooler volume, temperature range, and local solar data — full bill of materials within 48 hours.
