Case Study · Construction Site Hybrid Power

Cutting Diesel by up to 90% on a New Zealand Construction Site with SafeBatt Mobile BESS

WISE Energy, SafeBatt and NES Hire NZ deployed a solar-plus-battery hybrid power system at a New Zealand construction site, slashing diesel generator run-hours and fuel use by up to 90% in optimal solar conditions while keeping site offices, welfare facilities and equipment running around the clock.

The challenge

The site relied on a diesel generator running almost continuously to power site offices, welfare units and a covered work area. Running a generator 24/7 for a relatively small, variable load is expensive and inefficient: fuel is burned overnight and at low load when little power is actually used, generators wet-stack and wear when lightly loaded, and every litre has to be trucked to a remote site. On top of the fuel bill came noise around the clock, exhaust emissions, and the cost and downtime of frequent refuelling and servicing.

The solution

WISE Energy installed a SafeBatt Mobile BESS (battery energy storage system) alongside the existing NES Hire diesel generator, with solar PV panels mounted on the roof of the site container. The battery now carries the site load directly. Solar recharges the battery through the day, and the generator only starts when the battery needs topping up in poor weather or under peak demand. Instead of idling 24/7, the generator runs for short, high-efficiency bursts at proper load, then shuts down. This is a true hybrid power system (HPS): solar first, battery second, generator as a backup charger rather than the primary source.

The results

• Up to 90% reduction in diesel use in optimal solar conditions, with generator run-hours cut dramatically year-round.
• Far fewer refuelling and service visits lower logistics cost and site disruption.
• Near-silent overnight operation as the site runs on battery, not a running generator.
• Lower emissions and a smaller carbon footprint for the project.
• Same or better reliability with the generator always available as automatic backup.

Why SafeBatt

The SafeBatt Mobile BESS uses lithium iron phosphate (LFP) cells with integrated module-level fire suppression, active cooling and a design life of around 6,000 cycles. It is designed and assembled in Australia, includes remote GSM/GPS monitoring, and can be cascaded or run in parallel as site demand grows. The same platform is available for hire or purchase across a range of sizes, from single-phase skid units to containerised systems, for construction, events, mining, off-grid and remote power.