Stationary gas generators can operate on natural gas or liquefied petroleum gas (LPG). Both fuels are suitable for standby power, but they differ in storage, continuity of supply, design requirements and performance during a prolonged outage. The fuel should be chosen before the equipment is ordered because it affects configuration and available output.
Quick comparison
| Criterion | Natural gas | LPG |
|---|---|---|
| Fuel source | The building’s gas network | Cylinders or a storage tank |
| On-site reserve | No stored reserve | Stored in a designed system |
| Autonomy | Depends on continuity of the gas network | Depends on stored volume and consumption |
| Design checks | Pressure and pipe capacity | Storage, vaporisation and delivery |
| Maintenance | Gas line and generator | Also includes the fuel storage system |
When natural gas is convenient
Natural gas is often selected for a home or commercial building with an existing connection. Fuel does not need to be delivered or stored on site. With a correctly sized line, the generator can start automatically during an outage and operate without the owner handling fuel.
Before selecting a model, verify inlet pressure, pipe capacity and the simultaneous demand from other gas appliances. A gas pipe near the installation position does not by itself prove that the supply is adequate for the generator.
When LPG is suitable
LPG is useful where there is no gas main or where the owner needs a dedicated on-site reserve. Storage capacity is selected according to generator rating, expected electrical load and the required operating duration.
At low temperature and high consumption, the storage system must vaporise fuel at a sufficient rate. The tank, regulators and supply line therefore need to be designed as one system. Connecting a large stationary generator to an arbitrary cylinder is not a sound engineering solution.
Why the output rating can differ
The same generator model may have different output ratings on LPG and natural gas. This is a normal result of fuel and engine characteristics. Check the rating for the selected fuel, voltage and frequency, and confirm the final configuration against the manufacturer’s specification.
Can the generator change between fuels?
Many GENERAC models are designed for both natural gas and LPG. Dual-fuel capability does not mean the fuel should be changed without checks. The regulator must be configured correctly, the appropriate gas components must be installed and operating parameters must be verified after startup. A qualified specialist should perform this work.
What affects fuel consumption?
- actual electrical load;
- generator model and rating;
- ambient temperature;
- fuel quality and pressure;
- engine condition;
- operating duration and load sequence.
Autonomy should be calculated with the consumption table for the specific model at several load levels rather than with a single average figure for all generators.
Safety and installation
A gas generator must be installed in accordance with the manufacturer’s instructions, the approved gas design and applicable regulations. The design needs a suitable base, safe clearances, ventilation, exhaust routing, protection of the gas line and access for service. A generator must not operate in a living area or an unsuitable enclosed space.
Making the choice
For a property with a suitable and reliable gas network, natural gas is often convenient for long automatic operation. LPG may suit a property without a gas main or one that requires its own fuel reserve. The final decision follows an electrical load calculation and a check of the fuel infrastructure.
Browse the GENERAC gas generator catalogue or speak with a BASTION LTD engineer on +38 063 793 29 29.
