In short. Cleaner-fuel generator systems replace or reduce diesel with gas or renewable liquid fuels. Each fuel brings different supply, safety, performance and cost trade-offs, so choose from site fuel access and duty, not from a headline claim.
Options
| Option | Notes |
|---|---|
| Natural gas | Pipeline or CNG; relatively clean combustion. See gas generator systems |
| Biogas / Bio-CNG | Renewable source; composition varies, needs conditioning |
| LPG | Storage-based; suitable for some duties |
| Dual fuel | Diesel plus gas. See dual-fuel conversion |
| Bi-fuel | See bi-fuel engineering |
| HVO / renewable diesel | See HVO readiness |
Comparison criteria
- Fuel availability and price stability at the site.
- Storage and safety requirements.
- Engine suitability and conversion needs.
- Load response and derating.
- Emissions and regulatory acceptance.
- Total lifetime cost.
Standby versus prime duty
Standby sets rarely run, so fuel storage life and readiness matter more than efficiency. Prime sets run many hours, so fuel cost dominates.
Illustrative example
A food plant near a gas pipeline chooses a gas set for prime power. A remote hospital chooses a diesel set that can also use HVO, because gas delivery is unreliable.
Fuel property comparison (qualitative)
| Fuel | Storage | Handling | Typical consideration |
|---|---|---|---|
| Diesel | Tank on site | Familiar | Emission control needed |
| Natural gas by pipeline | None on site | Gas train and detection | Supply continuity |
| CNG | Cylinders or cascade storage | High pressure safety | Delivery logistics |
| Biogas | Gas holder | Cleaning and drying | Quality variation |
| LPG | Tanks | Heavier than air, leak behaviour | Siting and ventilation |
| HVO | Tank, as diesel | Similar to diesel | Approval and price |
Questions to ask about any fuel
- Can I get it reliably, in all seasons, at this site?
- Can I store enough for the longest outage I must cover?
- Does my engine run on it with maker support?
- What safety measures does it need?
- How does it affect emissions and compliance?
- What happens to cost if the price changes?
Hybrid fuel strategies
A site can use gas for routine running and keep diesel for emergencies, or use a cleaner liquid fuel in standby tanks. Mixed strategies often give the best balance between cost, compliance and resilience.
Standby fuel quality
Diesel stored for long periods can degrade or collect water and microbial growth. Test it, polish it if needed and rotate stock. Regular on-load tests also help keep fuel moving.
Document the choice
Record the fuel decision with reasons and assumptions. If supply conditions change, you can revisit the choice quickly. See fuel and lifecycle framework.
The master engineering question
Which fuel can the site get reliably, store safely and burn well in the chosen engine?
What to send us
Send duty, location and fuel options. Send your application details.
Questions engineers ask
Is gas always cheaper?
Depends on local tariffs; compute per kWh.
Is biogas reliable?
Only with consistent quality and supply.
Do I need new equipment?
Often some conversion or a new set.
Are emissions guaranteed lower?
Verify for the engine and fuel.
General guidance only. Verify fuel and engine data.