How to reduce generator fuel costs and improve fuel efficiency

Rising fuel prices and sustainability expectations are putting pressure on every site to optimise energy use. Cutting generator fuel costs is achievable without sacrificing reliability by right-sizing equipment, integrating battery energy storage, adopting cleaner fuels, and improving maintenance and monitoring practices. These steps also support emissions targets and help future-proof operations.

Right-sizing generators to match your power demand

What right-sizing means and why it matters

Oversized sets often run at low load, which wastes fuel, increases wet-stacking risk, and pushes up maintenance. Right-sizing matches generator capacity to your measured demand so engines spend more time in their efficient operating band. Guidance for critical facilities recommends an electrical load capacity analysis when selecting and sizing generators, not just nameplate estimates.

How load profiling improves selection

Start with a load study covering base demand, inrush currents, diversity factors, and duty cycles across day and night. Profile data helps choose a single set or a staged set-up that keeps engines operating efficiently across variable loads.

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Using battery energy storage to reduce run-time

How BESS reduces engine hours

Pairing generators with battery energy storage lets the battery handle low or variable loads and transients, so engines can switch off or run fewer hours at higher, more efficient load points.

Fuel-saving benefits

Pair a generator with a battery and the engine stops idling through quiet spells. Battery energy storage carries light and choppy loads and smooths step changes, so the generator runs fewer hours and, when it does, runs closer to its efficient load range. You burn less fuel and create fewer emissions, there is less noise on site, fewer refuelling runs, and longer gaps between services. This hybrid setup is a simple win for construction and remote sites where demand swings across the day, and it is a straightforward step towards microgrids if you want to go further

Switching to HVO for cleaner generator operation

What HVO is

Hydrotreated Vegetable Oil is a renewable diesel made by hydro-processing vegetable oils and fats. It meets diesel specs and can be used as a direct drop-in for Aggreko diesel generators, with no special filters required.

Emissions impact

Independent tests cited by Aggreko show HVO can reduce CO₂ emissions by up to 80 percent, NOx by up to 25 percent and particulate matter by up to 42 percent, while maintaining performance.

Deploying without major changes

Because HVO is drop-in compatible across Aggreko’s diesel fleet, there are no equipment changes to plan for in the hire setup. The main consideration in Australia is fuel availability and logistics, which are improving. Speak with us about current supply for your location.

Biofuel

Some Aggreko diesel generators can also operate on FAME-based biodiesel blends. Unlike HVO, biodiesel is not a universal drop-in across the fleet and typically needs OEM approval for the blend level, tighter fuel-quality control, and more frequent maintenance tasks such as filter changes and tank housekeeping. Service intervals and requirements vary by engine, so we’ll confirm approved blends and set a maintenance plan for your specific set and site conditions.

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Optimising fuel use with maintenance and monitoring

Regular service for efficient combustion

Keep filters, injectors, cooling and controls in spec to maintain a clean burn and safe operating temperatures. Schedule load bank testing to exercise sets under controlled load, prevent wet-stacking and confirm performance after maintenance.

Telemetry and remote monitoring

All eligible Aggreko equipment marked with the ARM sign is watched 24/7 by trained diagnostic engineers, with alerts for run status, load, fuel levels and faults. Our Remote Operations Centre can contact site teams, arrange technicians and even schedule fuel deliveries before you run low. This reduces unnecessary idling, avoids fuel run-outs and helps you plan service windows around real use.

Match output to real-time demand

Use staged sets with load-on-demand so only the generators you need are running. As site demand rises, additional sets start; as it drops, sets stop. This keeps each engine in its efficient load band, cuts low-load idling, and delivers direct fuel savings by reducing total run hours and lifting the average load factor. For predictable peaks, schedule extra capacity only for those high-load windows, then scale back off-peak. Pairing the fleet with battery energy storage covers light and choppy loads and shaves short spikes, so engines spend more time at efficient load and less time burning fuel unnecessarily. The result is fewer litres consumed, fewer refuelling runs, and longer gaps between services.

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Smarter strategies for fuel and cost savings

Recap the key moves

Right-size equipment and plan staged sets.
Add BESS to reduce run-time and low-load operation.
Where possible, switch to HVO to cut lifecycle emissions.
Monitor and maintain with clear KPIs and periodic load testing.

Next step

If you want a design review or a plan tailored to your load profile, speak with a specialist to scope the most efficient temporary or supplementary power set-up for your site.