Gas Turbine or Engine? Cycle summery.

In the context of electrical power generation, we usually talk about:

• Gas turbines, used mainly in large power plants, combined heat and power plants (CHP or cogeneration), and as a source of backup or prime power for industrial applications.
• Internal combustion engines, widely used in generator sets for standby, prime, or peak shaving applications, as well as for smaller-scale CHP.

Differences in Project Implementation

Implementing a project based on a gas turbine installation differs significantly from a solution based on internal combustion engines.

Scale and Power Output

• Gas Turbines: These typically offer much higher unit power outputs, often ranging from several to several hundred megawatts (MW). Investments in gas turbines are large-scale projects that require extensive infrastructure.
• Engines: Internal combustion engine generator sets offer a wide power range—from tens of kVA to several MW (also in parallel configurations). This makes them more flexible and scalable, suitable for smaller projects and as distributed energy sources. As an industry leader, Caterpillar offers a wide range of generator sets (Gas Gensets, Diesel Gensets) that can be configured into complex power systems.

Initial Costs (CAPEX)

• Turbines: The initial investment costs for gas turbines are generally much higher due to technological complexity, the size of the equipment, and the necessary infrastructure (e.g., gas connections, cooling systems, buildings).
• Engines: The cost of purchasing and installing a single internal combustion engine generator is relatively lower. Thanks to their modular design (e.g., the ability to install several generators side-by-side), power output can be expanded in stages, spreading out the investment over time. As a Caterpillar partner in Poland, Eneria offers competitive prices and support in selecting optimal solutions, which minimizes initial capital expenditure.

Space and Infrastructure Requirements

• Gas Turbines: These require a large amount of space, extensive ventilation and cooling systems, as well as specialized foundations and acoustic insulation. They are also more sensitive to fuel quality, which necessitates advanced gas treatment systems. For high-power systems, gas turbines are a more compact solution than gas engines of the same power output, which is one of their key advantages in large installations. Despite their initial requirements, gas turbines are notable for their significant power output and long lifespan, making them an ideal solution for large industrial and energy facilities. Their efficiency in producing electricity and heat (in CHP systems) often surpasses other solutions, compensating for their greater infrastructure needs.
• Internal Combustion Engines: Engine-powered generators are more compact for lower power applications, especially in a containerized version, which makes them easier to install even in limited spaces. They require less complex cooling infrastructure and can run on different fuel types (diesel, natural gas, biogas). Caterpillar offers containerized units, which significantly simplifies the installation process.

Implementation Time

• Gas Turbines: Turbine projects are complex undertakings that can take from several months to several years to complete. The timeline depends on the project’s scale and complexity, as well as the required permits. Although the implementation time is longer due to technological advancement and higher power output, gas turbines offer long-term efficiency and lower operating costs over their lifecycle. Their ability to run continuously and their high energy efficiency often justify the longer deployment period.
• Internal Combustion Engines: Deploying an engine-powered generator is much faster. Standard units are often available off-the-shelf or with a shorter lead time, and their installation usually takes just a few weeks. Thanks to its resources and experience, Eneria is able to efficiently execute projects related to the delivery and commissioning of both engine-powered generators and gas turbines.

Flexibility and Operating Mode

• Turbines: They are most efficient when operating continuously and close to full load. Frequent starts and stops shorten their lifespan and increase operating costs.
• Engines: They are characterized by greater operational flexibility. They can start and accept load quickly, making them ideal for standby applications (e.g., CAT standby generator sets), peak shaving, or CHP systems with variable heat and energy demands.

Operating Costs (OPEX)

Operating costs are another key factor to consider.

Fuel Consumption

• Turbines: In large installations, gas turbines can be very fuel-efficient, especially in CHP mode, where waste heat is utilized.
• Engines: Modern Caterpillar gas and diesel engines are also highly fuel-efficient, particularly with variable loads. In CHP mode, they achieve high overall efficiency (electrical and thermal).

Maintenance and Service

• Turbines: They require specialized and costly maintenance, often performed by the manufacturer or authorized service providers. Inspections are less frequent but more extensive.
• Engines: Engine maintenance is usually less complex and more affordable, though it requires more frequent inspections. Eneria offers comprehensive service packages for CAT generators, providing access to genuine parts and trained technicians, which translates to low operating costs and a long lifespan.

Emissions

• Turbines: They can have lower NOx and CO2 emissions per MWh, especially modern designs with advanced exhaust gas reduction systems.
• Engines: Modern CAT gas engines meet stringent emission standards, and for diesel engines, advanced exhaust aftertreatment systems are used (e.g., diesel particulate filters, SCR systems).

Summary

The choice between a turbine and an internal combustion engine depends on the specifics of your investment:

Therefore, if you are planning a large-scale energy project with a constant, high power demand, a gas turbine may be the right solution, although it requires higher initial capital and a longer implementation time.

If you are looking for a flexible, scalable, and quick-to-deploy power source for standby, prime, or CHP applications with power outputs ranging from tens of kVA to several MW, CAT generator sets with internal combustion engines, offered by Eneria, will be the optimal choice. They combine reliability, efficiency, and comprehensive service support.

Caterpillar and Eneria provide technologies that enable the effective implementation of both types of investments. The key is a thorough analysis of your needs, including power requirements, operational flexibility, available space, and budget.

You can hear more about the differences in selecting the right cogeneration solution for a specific investment in the latest video from the series “Turbines and Gas Engines – Complementary Solutions in Cogeneration.”

Author: Eneria Expert Team

Jakub Bigoszewski and Adam Kiciński

email: marketing@eneria.pl