Hybrid Solar for Mining Portable Offices: Cut Diesel Use, Keep Power On 24/7

At many mining sites and coal ports in Kalimantan, the field office is a portable office: a 20 ft or 40 ft container fitted with air conditioning, lighting, computers, radios, satellite internet, and CCTV. Its power almost always comes from one source, a generator running 24 hours a day.

The problem is that a portable office draws far less power than the generator is built for. A generator running at low load all day burns excess diesel, fouls its engine (wet stacking), and needs more frequent servicing. This is where a hybrid solar system helps.

What is a hybrid solar system for a portable office?

A hybrid system combines three energy sources managed by a single hybrid inverter:

1. Solar panels power the loads and charge the battery during the day.
2. LiFePO4 batteries carry light loads at night (lighting, internet, CCTV, radio).
3. The existing generator stays as backup for long cloudy spells or peak loads. The inverter can auto-start the generator when the battery drops below a set level.

The result: the generator no longer runs 24 hours, only for a few hours when it is actually needed, and when it does run, it works at a more efficient load.

Sizing example: 40 ft container, 6–8 staff

The figures below are illustrative. The final design always follows an on-site load survey.

• 2 × 1 HP air conditioners, ~10 hours: ~10 kWh/day
• 10 LED lights, 12 hours: ~2 kWh/day
• 6 laptops/PCs, 10 hours: ~4 kWh/day
• Printer, water dispenser, small fridge: ~2 kWh/day
• Starlink, router, and switch, 24 hours: ~2.5 kWh/day
• 4 CCTV cameras + NVR, 24 hours: ~1.5 kWh/day

Total ~22 kWh/day, with a night load of about 5 kWh.

A suitable configuration:

• Panels: 10 × 650 Wp (6.5 kWp). With an average of 4 peak sun hours in Kalimantan and system losses taken into account, output is around 20 kWh/day.
• Hybrid inverter: 6–8 kW, 48 V system, with generator input and auto-start.
• Battery: LiFePO4 48 V ~150 Ah (~7 kWh), enough for the night load with headroom.
• Generator: kept in place as backup.

For reference, a generator running 24 hours at low load can use around 30–36 litres of diesel a day. With a hybrid system, it may only need to run 2–4 hours on cloudy days or during peak load. Actual savings depend on the generator, usage pattern, and weather.

Technical points for mining sites

• Limited roof area. A 40 ft container roof is only about 29 m², just enough for 10 panels. For more capacity, panels can go on a canopy frame beside the container, which also provides shade.
• No roof drilling. Use removable clamp frames so the roof stays watertight and the system can move with the office when it is relocated.
• Mine dust. Coal and soil dust reduce panel output. Choose anti-dust panels and schedule regular cleaning.
• Heat. Inverters and batteries should sit in a ventilated cabinet out of direct sunlight.
• Electrical safety. DC isolators, MCBs, surge protection (SPD), and tested grounding are essential. Add lightning protection where needed, as open mining areas are prone to strikes.
• Remote monitoring. An inverter with a WiFi/LAN module can be monitored over the existing Starlink link, so battery status and output can be checked from head office.

When does hybrid solar make sense?

• The portable office will be in use for at least 1–2 years, at one site or moving between sites.
• Diesel delivery to the site is costly or logistically difficult.
• The company has emission-reduction or ESG targets.
• CCTV, radio, and internet need uninterrupted power at night without running the generator.

CV. Connect services

CV. Connect provides load surveys, system design, supply of panels, inverters, and batteries, through to installation and maintenance of hybrid solar systems for portable offices, guard posts, and watchtowers at mining and port sites. Systems can be integrated with existing CCTV, Starlink, and network infrastructure.

Discuss your site's needs with us via CV. Connect WhatsApp.