How to design an integrated charging hub — and make it pay
Published on September 11, 2026
EV charging demand is growing fast across Southeast Asia and Central Asia, but many projects hit the same wall: the grid connection is too small, upgrading it is expensive, and peak tariffs hurt. An integrated solar + storage + charging system solves the capacity bottleneck while cutting your power bill. Here is how to design one.
Why integrate solar, storage and charging
Limited grid capacity: several fast chargers running at once draw enormous power. Storage discharges during peaks so you avoid a costly transformer upgrade.
Time-of-use tariffs: charge the battery off-peak, use it to charge vehicles at peak — capturing the spread.
Demand charges: charging loads are spiky. Storage shaves those peaks and lowers the monthly demand charge.
Green power & ESG: on-site solar raises your renewable share — a growing requirement for industrial parks and corporate fleets.
What the system consists of
PV array: rooftop or carport solar, generating during the day when vehicles are parked.
Battery storage: LiFePO4 plus PCS — the core of peak shaving. Typically a 100kW/215kWh cabinet or a containerized unit for larger hubs.
Chargers: AC (7–22kW) for long dwell times, DC fast chargers (60kW+) for quick turnaround.
EMS: the brain that coordinates PV, battery, chargers and grid, deciding when to charge and discharge.
Three typical scenarios
1. Workplace / industrial park charging
Employees park during the day, which matches solar generation well. A 100kW/215kWh cabinet plus several AC chargers earns mainly through solar self-consumption and peak shaving.
2. Public fast-charging hub / highway stop
Load concentrates in daytime and holidays with heavy power spikes. Larger storage (500kWh–1MWh+) plus DC fast chargers — the value is avoiding grid upgrades plus tariff arbitrage.
3. Weak-grid or off-grid sites
For mining sites, islands and remote stops where the grid is weak or expensive, solar-storage-charging can run largely independently, with a diesel genset only as backup.
How to size the system
Work in this order: charging power first, then storage, then PV.
Total charging power: number of chargers × power per charger × diversity factor (typically 0.6–0.8).
Storage power: cover the portion of charging load exceeding your grid capacity — usually 40–70% of total charging power.
Storage capacity: based on daily charging energy and the off-peak charging window; commonly 200kWh to 1MWh.
PV capacity: whatever the carport or roof area allows, designed around "self-consume first, store the surplus".
Where the revenue comes from
Tariff arbitrage: cheap off-peak energy stored and used at peak.
Demand charge reduction: flattening spikes cuts the monthly maximum demand.
Solar self-consumption: displacing expensive grid power with low-cost PV.
Avoided grid upgrade: often the biggest hidden saving — no new transformer, no new cable.
Charging service fees: your core business, now no longer capped by grid capacity.
Equipment selection essentials
Battery: LiFePO4, 6000+ cycles, tolerant of frequent partial cycling.
PCS: sized for charging peaks; on/off-grid transfer capability adds flexibility.
Chargers: modular DC units allow later expansion; confirm EMS communication protocol.
EMS: must support PV forecasting, tariff schedules and SOC protection.
Fire safety & thermal: cabinets and containers need air-conditioning and automatic suppression; charging hubs get strict fire review.
Implementation notes
Confirm grid capacity and connection scheme with the utility early.
Observe fire separation distances — charging hubs are public spaces with strict rules.
Keep a manual override on the EMS for maintenance and extreme weather.
Reserve space and electrical capacity for future expansion as traffic grows.
Planning a solar-storage-charging project? Tell us your charging power, daily traffic and site conditions — we'll provide a system configuration and savings model.