A 225 kW high-voltage solar hybrid upgrade for a Lagos pharmaceutical manufacturer

Rooftop solar arrays on the factory in Lagos.

The client and the facility

The client is a pharmaceutical manufacturer in an industrial area of Lagos. The factory runs mainly in the daytime, from about 7am to 6pm, and relies on steady power to keep production going.

In 2022 we installed a solar hybrid system of about 159.5 kWp: 290 working 550 Wp modules, eight 12 kW Deye low-voltage hybrid inverters (96 kW in total), about 80 kWh of lithium storage and a separate 100 kW Deye PV string inverter. It was completed in November 2022 and cut the factory's use of grid power during the day.

The challenge

Years of running data showed one weak point. When the grid went off, the low-voltage battery setup could not always deliver the sudden burst of power the factory needed. Some grid-to-battery switchovers caused interruptions and system restarts.

• Peak demand of about 76 kW, plus about 22 kW of extra starting load, so short peaks near 98 kW.
• Grid outages of up to about 90 minutes.
• The limit was the power delivery of the original 51.2 V battery design, not the amount of solar on the roof.

Our approach to the solar hybrid upgrade

We didn't just add more batteries. We treated it as an engineering problem and proved the design with data first.

• 72-hour energy audit. We logged peak and average demand, daily energy use, load steps, starting currents and power factor across three full days.
• Engineering check. We used the measured data to confirm inverter size, battery setup, PV strings, AC distribution and grid and generator integration before buying equipment.
• Two-layer loads. All office lights and office ACs are critical loads. Two of the three large HVAC units run on the hybrid and string system; on heavy-rain days they run only if there's grid.
• Keep what still works. The 100 kW string inverter and the existing 550 Wp modules stayed in service, rewired for the new system.

The solution

• Hybrid inverter: 1 × Deye SUN-125K-SG02HP3-EU-GM10, 125 kW high-voltage hybrid, replacing eight 12 kW low-voltage units.
• Battery storage: Deye BOS-B Pro-A3 high-voltage lithium system with battery management and cluster box, 192.72 kWh.
• New solar PV: 65.45 kWp of new modules on the roof.
• Existing PV: 159.18 kWp of 550 Wp modules, rewired into new string layouts.
• Retained inverter: existing 100 kW Deye PV string inverter, tested and integrated.
• Grid and generator: grid input plus generator input with auto-start control, feeding the main facility distribution panel.

Delivery

• Awarded on 27 July 2026 and completed on 29 August 2026, about five weeks from award to completion certificate.
• Work ran in a planned order to limit disruption to production: audit, engineering check, procurement, careful removal of the old inverter bank, installation, then integration.
• Commissioning covered grid-to-battery transfer tests, battery operation, PV output, generator interaction and protection tests.
• Handed over with an updated as-built drawing set and power schematics.

Before and after

Results

• 2.4 times the battery storage, on a high-voltage platform built for commercial loads.
• About 41% more solar capacity on the same roof.
• One inverter instead of eight, which is simpler to run, monitor and maintain.
• Money saved on existing assets, because the 100 kW string inverter and the original modules stayed in service.
• Signed completion certificate from the client on 29 August 2026.