Off-Grid solar energy storage system in Yemen - MOTOMA case study 22kW 30kWh

A Reliable Off-Grid Microgrid Solution for Residential and Commercial Loads

In response to the challenges of frequent power outages and unstable grid access in Yemen, MOTOMA successfully deployed a customized solar-plus-storage energy solution. The system includes:

• Two Axpert MAX TWIN 11kW off-grid inverters (total inverter capacity: 22kW)
• Two M89 model lithium iron phosphate (LiFePO₄) battery packs, each 15.36kWh (total usable capacity: 30.72kWh)
• An estimated 8–10 units of 550W solar panels per inverter, forming a smart and autonomous microgrid capable of seamless day-night operation.

System Configuration and Technical Estimates

Battery System:

• Model: M89 (51.2V, 300Ah, 15.36kWh per unit), connected in parallel
• Total storage capacity: 30.72kWh
• Maximum discharge capability: up to 15.36kW at nominal voltage
• Usable daily energy (based on 80% depth of discharge): approx. 24.6kWh

Solar Generation:

• Inverter maximum PV input current: 27A × 2 = 54A
• MPPT voltage range: 90–450VDC
• Assumed panel configuration: 8 × 550W per inverter (total PV capacity: 17.6kWp)
• Yemen‘s average solar irradiation: 5.5–6.5kWh/m²/day
• Estimated daily generation: approx. 105–110kWh
• Supports full energy independence: daytime generation powers loads and charges batteries, nighttime use from stored energy

Load Capacity:

Peak load support: up to 22kW combined inverter output

Typical supported appliances:

• 3 × 1.5HP air conditioners
• 2 refrigerators
• Up to 20 lighting circuits
• Water pumps, kitchen appliances, computers, routers, TVs

Example: 4kW average load can be supported for over 6 hours continuously

Installation Procedure Overview

All installation work should be carried out by qualified electrical technicians.

1. Positioning and Layout Planning: Ensure good ventilation and clearance for heat dissipation; avoid direct sun and moisture.
2. DC System Wiring: Connect PV modules in series with appropriate safety components; ensure correct battery polarity.
3. AC System Integration: Connect to user distribution panel; separate programmable output if needed; isolate any grid/generator input.
4. Commissioning and Configuration: Set modes, priorities, and test all functions via LCD and mobile app.

Installation Notes and Safety Considerations

• Ensure complete grounding for safety
• Use surge protectors and lightning rods where applicable
• Inspect terminals every 3 months and monitor system health regularly
• Ensure communication protocols between BMS and inverter are correctly configured

Project Highlights

Powering Sustainable Progress with MOTOMA

This successful deployment in Yemen reflects MOTOMA’s commitment to advancing renewable energy access in off-grid and energy-challenged regions. Whether you‘re managing government infrastructure, NGO-led electrification, commercial microgrids, or private investments, MOTOMA offers fully tailored solar storage solutions to ensure energy independence, reliability, and long-term savings.