Operational Cost Analysis: Diesel vs Gas in Generator Sets
Choosing the right fuel type for a generator set is a critical decision that directly impacts operational costs and the efficiency of the power supply. The most common options are diesel generators and those powered by natural gas. This article provides a comparative overview of both systems, examining their advantages, disadvantages, and suitability based on the energy demands of each sector.
Factors Influencing the Operational Costs of a Generator Set
The operational cost of a generator set depends on more than just the fuel price. Other key factors include:
- Fuel consumption according to load and operating hours.
- Maintenance frequency and spare parts requirements.
- Engine durability, depending on the type of fuel used.
- Fuel supply availability and logistics at the project location.
- Thermal performance and energy conversion efficiency.
- Environmental regulations relating to fuel emissions.
These elements influence long-term investment, especially in industrial environments or critical applications where continuity of power supply is essential.
The most common options are diesel generators and those powered by natural gas.
Price Comparison: Diesel vs Natural Gas
Diesel has long been a reliable choice, but the price of natural gas is often more competitive, particularly for long-duration or continuous-use applications.
- Diesel is subject to volatile pricing, influenced by global markets and specific fuel duties.
- Natural gas generally offers more stable and predictable costs, making operational and financial planning easier.
Furthermore, long-term contracts with gas suppliers allow many industries to manage their operating energy costs more effectively.
Efficiency and Fuel Consumption: Diesel vs Gas Generators
Diesel generators typically deliver high efficiency under variable load conditions and quick start-up, making them ideal for short-duration or standby use. Their design allows for high power output within a short time frame.
In contrast, natural gas generators offer:
- Lower specific fuel consumption in continuous, stable-load operations.
- Cleaner combustion with fewer residues.
- Improved thermal efficiency, particularly when used in combined heat and power (CHP) systems.
- Lower noise and vibration levels, enhancing operational comfort.
Impact on Lifespan and Maintenance of Generator Sets
The type of fuel also affects equipment lifespan and maintenance needs:
- Diesel engines require more frequent maintenance, including regular oil and filter changes and injector checks.
- Natural gas engines generally allow longer intervals between servicing, with some models offering up to double the maintenance cycle compared to diesel engines.
However, gas engines require specific components, such as spark plugs and advanced air-fuel mixing systems, which demand specialised care.
Generator sets must meet new market challenges with the lowest possible operating cost and the highest commitment to sustainability.
Industrial Applications and Energy Demands Based on Fuel Type
The choice between diesel and gas depends on the specific power supply needs and application context:
- Diesel generators: well-suited for emergency backup, quick starts, mobile use, and remote areas without gas infrastructure.
- Gas-powered generator sets: ideal for continuous operation, thermal-electric cogeneration, and facilities with access to natural gas or biogas networks.
Industries such as manufacturing, logistics hubs, hospitals, data centres, public infrastructure, and agri-food facilities can benefit from either type depending on operational requirements.
Sustainability and Emission Reduction with Natural Gas
Natural gas is increasingly seen as a more environmentally friendly alternative to fuels such as diesel:
- Significant reduction in NOx, CO₂, SO₂ and suspended particulate matter (PM10 and PM2.5), mainly generated by incomplete combustion in diesel engines.
- Reduced impact on air quality, especially in urban or enclosed environments.
- Lower odour and noise pollution.
- Reduced risk of soil contamination in case of leaks.
In addition, using biogas or renewable natural gas brings operations closer to carbon neutrality, in line with European decarbonisation goals.
How to Choose the Best Option for Your Power Supply Needs
Deciding between gas and diesel depends on several key considerations:
- Expected operating duration of the generator set (standby vs continuous).
- Fuel availability and delivery logistics in the area.
- Environmental restrictions and local regulations.
- Climatic conditions and technical project requirements.
- Available budget, covering both CAPEX and OPEX
For projects requiring long annual operating hours, gas is often more cost-effective in the long term. In contrast, for installations with sporadic use or urgent demand, diesel remains a robust and practical choice.
Trends and the Future of Fuel Use in Generator Sets
The shift towards a cleaner energy model is encouraging the adoption of alternative fuels, such as biogas, LPG, green hydrogen, or HVO blends (hydrotreated vegetable oil).
In addition, using biogas or renewable natural gas brings operations closer to carbon neutrality,
Hybrid systems that combine generator sets with renewable energy and battery storage are also gaining traction, offering more flexible and sustainable power solutions.
In the short to medium term, natural gas will remain a key solution for efficient and sustainable electricity generation, particularly in industrial settings and medium-to-large-scale projects.
Meanwhile, diesel generators will continue to play a vital role in applications requiring immediate response and proven reliability, such as hospitals, telecommunications, and emergency systems.
Ongoing technological development, tighter environmental regulations, and the demand for flexible energy solutions will shape the sector’s future, where generator sets must meet new market challenges with the lowest possible operating cost and the highest commitment to sustainability.
