Analysis of operating costs: diesel vs gas in generator sets

The operating cost of a generator set does not depend solely on the fuel price. Factors such as the following also influence:

• Fuel consumption according to load and operating hours.
• Frequency of maintenance and necessary spare parts.
• Engine durability depending on the type of fuel.
• Availability and logistics of supply at the project location.
• Thermal performance and energy conversion efficiency.
• Regulatory requirements on emissions depending on the fuel used.

These elements condition long-term investment, especially in industrial environments or critical applications where it is necessary to ensure service continuity.

Among the most common options are diesel generators and those that run on natural gas.

Historically, diesel has been a reliable option, but the price of natural gas is usually more competitive, especially in long-duration or continuous-use applications.

* Diesel can have more volatile prices, subject to international market variations and special taxes.

* Natural gas, on the other hand, offers more stable and predictable costs, which can facilitate operational and financial planning.

Additionally, the possibility of long-term contracts with gas suppliers allows many industries to more precisely control their operational energy costs.

Diesel generators are often noted for their high efficiency in variable load regimes and quick response, making them ideal for short-term or backup applications. Their design allows for high power outputs in very short times.

On the other hand, natural gas generators offer:

• Lower specific consumption in continuous operations at stable load.
• Cleaner operation, with fewer combustion residues.
• Better thermal performance, especially in combination with cogeneration systems.
• Lower noise and vibration levels, improving the operational experience.

The type of fuel also affects the durability and maintenance of the equipment:

• Diesel engines require more frequent maintenance intervals, with regular oil changes, filters, and injector checks.
• Natural gas engines tend to have a longer lifespan between overhauls, and in some models, maintenance intervals can double those of diesel engines.

However, gas engines require specific components, such as spark plugs and more precise air-fuel mixing systems, which require specialized attention.

Generator sets must adapt to new market challenges with the lowest operational cost and the greatest commitment to sustainability.

Industrial applications and energy demands according to fuel type

The choice between diesel and gas will depend on the specific electrical supply needs and the application environment:

• Diesel generators: suitable for emergency backup, quick start, mobile environments, and areas without gas infrastructure.
• Gas generator sets: recommended for continuous use, thermal-electric cogeneration, and environments with access to natural gas or biogas networks.

Sectors such as manufacturing, logistics centers, hospitals, data centers, public infrastructure, or agro-industrial facilities can benefit from one type or another depending on their operational characteristics.

Natural gas is presented as a more environmentally friendly alternative compared to fuels like diesel:

• Significant reduction in emissions of NOx, CO2, SO2, and suspended particles (PM10 and PM2.5), mainly generated by incomplete combustion in diesel engines.
• Less impact on air quality, especially in urban or enclosed environments.
• Reduction of odor and noise pollution.
• Lower risk of soil contamination in case of leaks.

Additionally, the possibility of using biogas or renewable natural gas allows for a move towards carbon-neutral generation, aligned with European decarbonization goals.

How to choose the best option according to electrical supply needs

Choosing between gas or diesel will depend on several factors:

• Expected duration of operation of the generator set (backup vs continuous).
• Availability and logistics of fuel in the area.
• Environmental restrictions and local regulations.
• Climatic conditions and technical requirements of the project.
• Available budget, for both CAPEX and OPEX.

In projects where the generator set must work for many hours a year, gas tends to be more cost-effective in the long run. On the other hand, for installations with sporadic use or emergencies, diesel remains a robust and cost-effective option.

Trends and future in the use of fuels for generator sets

The transition towards a cleaner energy model is driving the adoption of alternative fuels, such as biogas, LPG, green hydrogen, or blends with HVO (hydrotreated vegetable oil).

Additionally, the possibility of using biogas or renewable natural gas allows for a move towards carbon-neutral generation.

Hybrid systems that combine generator sets with renewable energies and energy storage are also gaining prominence, offering more flexible and environmentally friendly solutions.

In the short and medium term, natural gas will continue to be a key option for efficient and sustainable electricity generation, especially in industrial environments and medium to large-scale projects.

Meanwhile, diesel generators will continue to play an essential role in applications that require immediate response and proven reliability, such as hospitals, telecommunications, and emergency systems.

Technological evolution, advances in environmental regulations, and the demand for flexible energy solutions will shape the future of the sector, where generator sets must adapt to new market challenges with the lowest operational cost and the greatest commitment to sustainability.