Petrol, Diesel or Gas: Which Fuel is Right for Your Emergency Generator?
A power outage can last longer than expected – be it due to storms, technical malfunctions or energy supply bottlenecks. Those who own an emergency generator have a choice between different fuels. However, petrol, diesel, and gas differ significantly in terms of performance, handling, storage, and safety.
Key Points
Petrol generators are lightweight, mobile and relatively inexpensive. They are primarily suitable for short-term outdoor use.
Diesel generators are robust, economical and particularly interesting for stationary emergency power solutions with higher power requirements.
Gas generators operate cleanly and with little odor, but are less flexible depending on supply situation and fuel reserves.
1) Why the choice of fuel is so important
The choice of fuel not only determines how long a power generator can run. It also influences acquisition costs, maintenance, noise level, storage capacity, safety, and the suitable place of use.
A small mobile generator for the garden, camping, or short-term emergency supply has different requirements than a stationary emergency power system for a building or a business. Therefore, it is worth comparing the three typical variants: petrol, diesel, and gas.
2) Petrol engine – light, quiet and mobile
Petrol generators are often used for mobile applications and smaller consumers. They are particularly interesting if the device needs to remain portable and is only used temporarily.
Advantages of Petrol Generators
- Very quiet operation
- Low weight and therefore easy to transport
- Relatively low acquisition costs
- Well suited for short-term outdoor applications
Disadvantages of Petrol Generators
- Petrol is highly flammable and must not be stored indoors.
- Stationary installations indoors are therefore excluded.
- The fuel has a limited shelf life and ages faster.
- Petrol lasts for several years in an airtight metal canister under optimal conditions, but only about 2 to 3 months in a plastic canister; with stabilizers up to 3 years.
- Consumption is higher than with diesel.
Practical recommendation: For mobile use in the garden, for camping or as a short-term emergency power supply, petrol generators are a good solution. However, they should be operated outdoors and only cover the current demand.
3) Diesel engine – robust and economical
Diesel generators are considered the classic choice for a permanent and reliable emergency power supply. They are particularly interesting when higher power is regularly required or a stationary solution is planned.
Advantages of Diesel Generators
- Very reliable and durable
- Can be operated with heating oil or biodiesel
- Start reliably even at very low temperatures
- Lower fuel consumption and high economic efficiency
- Stationary diesel generators can automatically take over within a few seconds when the grid fails.
Disadvantages of Diesel Generators
- Larger and heavier than many petrol models
- Installation and maintenance require expertise
- Noise and vibrations are higher
- Exhaust gases must be safely discharged outdoors
- Acquisition costs are higher than for petrol models.
- Diesel has a shorter shelf life than petrol, as biodiesel components can promote bacterial growth and sludge formation.
- By using HVO, the storage period can be significantly extended.
Typical use: Diesel generators are suitable for continuous operation, for households with higher power requirements or when an automatic start in case of power failure is desired.
With adequate ventilation, diesel generators can be installed stationary. Planning, exhaust gas routing, grid switching and fuel supply should be carried out professionally.
4) Gas operation – clean, but dependent on supply
Gas-powered emergency generators using natural gas or liquefied petroleum gas offer a clean alternative with lower emissions. However, practical suitability largely depends on how reliable the gas supply is in an emergency.
Advantages of Gas Generators
- Very quiet operation and hardly any odor
- Low pollutant emissions
- Liquefied petroleum gas (LPG) can be stored in bottles or tanks and has a long shelf life under normal conditions.
Disadvantages of Gas Generators
- Natural gas appliances are connected to the supply network.
- Gas heaters, gas stoves and gas water heaters often do not work in the event of a power failure without their own emergency power supply, as ignition and safety devices are electrically controlled.
- In the event of a prolonged blackout, it is unclear how long the gas network will remain functional.
- Liquefied petroleum gas requires its own tanks or bottles, the replenishment of which may be uncertain in times of crisis.
- Gas generators are less common and more expensive to purchase.
Important: Gas-powered devices are particularly suitable for short-term use and for low power requirements, provided sufficient gas reserves are available. However, in the event of prolonged power outages, the supply is not guaranteed.
5) Storage of fuels
The safe storage of fuel is regulated by law. In Germany, according to the Garage Ordinance, a maximum of 200 liters of diesel and 20 liters of petrol may be stored in tightly sealed, break-proof containers in small garages up to 100 m². In larger garages, storing fuels outside of vehicles is not permitted.
Additional regulations apply to heating oil, gas cylinders or other fuels. It is therefore always important to observe the specific requirements for storage location, quantity, containers and fire protection.
Basic rules for safe storage
- Store fuel only in designated, shatterproof containers.
- Storage rooms must be well ventilated and protected from sparks or open flames.
- Regularly check the condition of the containers.
- Do not use old fuel unchecked, as it can damage equipment.
Practical rule: Fuel storage should not only be planned according to quantity, but also according to shelf life, fire protection, ventilation and safe access in an emergency.
Conclusion – finding the right generator
The choice of the right fuel depends on your requirements:
- Petrol: Light and inexpensive, ideal for mobile, short-term outdoor use.
- Diesel: Robust solution for stationary operation, economical in consumption and suitable for automatic emergency power systems.
- Gas: Clean alternative, but dependent on gas supply and less common.
Remember that gas heaters and gas appliances may not work in the event of a power outage without their own emergency power source for safety reasons. Store fuels in accordance with regulations and have stationary systems installed by specialists.
We at SEV GmbH will be happy to advise you on the selection of the right emergency power generator and help you find the optimal solution for your home or business.
Contact us