The question almost always comes through the same channel: the company has set an emission reduction target, the inventory pointed out the generators, and someone needs to solve it. The first answer that comes up is to change the fuel.
Fuel is one part of the equation, and not always the biggest. Reducing emissions in generator rental depends on four decisions, and three of them have nothing to do with what goes into the tank. Follow along to see all four.
Executive summary
- A generator emits based on the fuel it burns, and sizing determines more than the type of fuel.
- The range of 50% to 80% of the nominal capacity is where the generator set performs best.
- Without telemetry, the reduction happens and doesn’t get into the emission report.
Index
- Why changing only the fuel solves little
- The four decisions that change the number
- How to take this to the rental contract
- Frequently asked questions about reducing emissions in generator rental
- Conclusion
Why changing only the fuel solves little
A generator emits based on how much fuel it burns, and burning less depends on three variables: the applied load, the operating time, and the equipment’s efficiency at that load point.
A generator set working at 30% capacity consumes proportionally more per kilowatt delivered than the same equipment at 75%. An underloaded diesel engine also accumulates a known operational problem, with deposit formation and performance drop over time.
In practice, an oversized piece of equipment running on renewable fuel can emit more than a correctly sized piece of equipment running on regular diesel.
The four decisions that change the number
1. Generator Sizing
Generator sizing is the most impactful decision and the cheapest to correct because it happens before delivery.
Sizing based on actual load, rather than the sum of the installed nameplate power, usually reduces one or two equipment ranges, and less installed power means less fuel consumption in operation.
The practical criterion is to operate in the range of 50% to 80% of nominal capacity most of the time, with room for the motor’s starting peak, within the regime that ABNT NBR ISO 8528 defines for that generator set.
2. The Fuel
Fuel is the second decision, and each sustainable fuel option available today has its limit. The specification of what is sold in the country and the mandatory blending percentage are defined by ANP.
- Biodiesel in generators is already present in the diesel sold in Brazil, and percentages above the mandatory level require confirmation from the engine manufacturer and care with storage, as the blend absorbs more moisture.
- Natural gas generators reduce particulate matter and usually have lower emissions per kilowatt generated, but they depend on a network or cylinder logistics, which restricts where they make sense.
- Renewable fuel of plant origin, such as HVO, yields better per liter, and the limitation today is availability and price in the Brazilian market.
The choice of fuel only makes sense after sizing, as changing the fuel of the wrong equipment means paying more for the same waste.
3. Hybrid with Battery
The generator with a battery, in a hybrid arrangement, solves the worst efficiency scenario, which is the low load period.
The battery meets small demand and short fluctuations, and the engine only starts when the load justifies it. On construction sites and at events, this reduces engine running hours, which translates to consumption and emissions.
The usage criterion is variation: it makes sense when there is a large load fluctuation throughout the day, and it makes little difference in operation with stable and high load.
4. Telemetry and Measurement
Generator telemetry is what makes the reduction verifiable, because without measurement the company changes fuel and cannot prove results.
Real-time monitoring records operating hours, average load, consumption, and alarms, and this history supports the emission report by actual consumption, in the format that ABNT NBR ISO 14064 requires for greenhouse gas inventory.
Tecnogera provides this data via telemetry and uses the load history to resize the equipment in the next contract, instead of repeating the power of the previous contract.
How to Bring This to the Rental Contract
Reducing emissions in generator rental also involves the contract, and three points agreed upon during contracting prevent discussions later.
- Request the expected load profile within the technical proposal, not just the power, because this requires the sizing to be justified.
- Define whether there will be telemetry, who receives the data, and how often, as this combination becomes evidence in the report.
- Record which fuel will be used and who is responsible for refueling, as this changes the emission calculation and the responsibility for storage.
How Tecnogera prepares the proposal
Tecnogera operates rental with telemetry and technical teams in 28 units, with 24-hour service, and prepares the proposal based on the informed load profile. Provide the load, usage profile, and city of operation to receive a proposal.
Frequently asked questions about reducing emissions in generator rental
Does a gas generator emit less than diesel?
The natural gas generator usually emits less, especially in particulate matter, but the correct comparison is per kilowatt generated and takes into account the availability of gas at the operation site.
Can I use pure biodiesel in the rented generator?
It depends on the engine manufacturer’s authorization and the maintenance plan. Percentages above what the commercial blend already provides require technical confirmation and care with storage.
Is larger equipment safer?
Larger equipment is safer against power shortages and worse in consumption, as oversizing increases cost and emissions and also harms the engine by operating at low load.
What is the ideal load range?
The ideal range is between 50% and 80% of the nominal capacity most of the time, with room for the startup peak.
Is a hybrid with battery suitable for any operation?
The hybrid with battery is better suited when the load varies greatly throughout the day, and in stable and high load operation, the gain is small.
How to prove the reduction for the sustainability report?
The proof comes from the measured consumption and recorded operating hours, and telemetry provides this basis, which supports the emission calculation better than the estimate by installed power.
Does renewable fuel require equipment changes?
It depends on the type of fuel, because some are compatible without modification and others require adjustment or manufacturer approval. It’s a question to ask before signing the contract.
Does noise emission also count?
Noise emission counts in licensing and in neighborhoods, with limits that vary by municipality and measurements made using the ABNT NBR 10151 method. Proper enclosure and correct positioning solve most of it.
Does maintenance influence emissions?
Maintenance directly influences: a saturated filter, unregulated injection, and expired oil increase consumption and emissions. A preventive maintenance plan is part of the environmental equation, not just reliability.
Is it worth changing the fuel if the operation is short?
In operations lasting only a few days, the absolute gain is small. The effort yields more in proper sizing and turning off the equipment when there is no load.
Conclusion
Reducing emissions when renting a generator is, in most cases, reducing consumption, and consumption is reduced with the right equipment, at the right load, turned on only when needed.
Fuel comes after that, as the last layer of an equation that starts with sizing and that Tecnogera closes with telemetry history, instead of estimation by installed power.
