Gas engines and gas turbines – two alternative technologies in cogeneration. Which one to choose?

Cogeneration is the process of simultaneously generating electricity and heat from a single fuel source. It is an effective and environmentally friendly way to meet the energy needs of both individual and industrial customers.

The correct selection of the type of cogeneration unit is therefore crucial for a given investment. In this article, we will discuss the two main types of cogeneration installations: those based on gas engines and those based on gas turbines.

We will present the strengths of both solutions to help you make an informed decision about which technology is best for your business.

Gaz engines are the preferred solution for smaller installations or those where we need low-parameter heat. Up to a size of about 5MWe, they are relatively inexpensive to install and operate and are characterized by high electrical efficiency. Gas engines can operate on natural gas, biogas or syngas.

Advantages:

• Low purchase and installation price for small installations;
• High electrical efficiency;
• Possibility of working on different types of gas.

Różnice w stosunku do turbin gazowych:

• Mniejsza moc;
• Odznaczają się wyższym poziomem hałasu;
• Często wymagają więcej miejsca na instalację;
• Ważna jest jakość paliwa zasilającego.

Turbiny gazowe

Gaz turbines are powerful devices that are perfect for applications where a large amount of electrical energy or high-parameter heat is required. For small installations (up to 5MWe), they are more expensive than gas engines. On the other hand, they are significantly cheaper on a larger scale. The electrical efficiency of gas turbines increases with size.

Gas turbines are devices that can work in a multi-fuel system, the quality of the fuel is secondary here. In addition to natural gas, we can power the turbine with diesel oil, biogas, kerosene, and other fuels with a calorific value above 17MJ.

Potential hydrogen supply is also much easier on a gas turbine, which can already burn it today.

Source: Eneria. Construction of a modern high-efficiency gas cogeneration system based on a gas turbine – Taurus 60 for a new production line at the plant in Starachowice – Cerrad sp. z o.o.

Advantages:

• High power of the device;
• High total cogeneration efficiency;
• Long service life – infrequent maintenance during the life cycle;
• Low exhaust emissions;
• Ability to operate on different types of fuel;
• Relatively compact in the installation in relation to the installed power;
• Ability to operate from 10% load.

Differences in relation to gas engines:

• Economical for medium and large installations (over 5MWe); L
• ower electrical efficiency for smaller devices;
• Devices that can operate in continuous mode.

Source: Eneria. A 4.5 MWe CATERPILLAR CG260-16 generator installed at JMP Flowers.

Which solution to choose?

Ultimately, the choice of cogeneration technology for your business will depend on a number of factors, such as:

• Heat and electricity demand;
• Budget;
• Space availability;
• Technical possibilities.

If you are looking for more power, and space or budget are constraints for your investment, then a gas turbine should be the first choice. For a small installation or one that requires little care your attention should turn to a solution such as a gas engine.

Additional benefits of cogeneration

In addition to energy efficiency and low emissions, cogeneration offers a number of other benefits, such as:

• Energy security: Cogeneration allows for local generation of electricity and heat, which reduces dependence on external energy suppliers.
• Lower energy costs: Cogeneration can reduce energy costs for businesses and industrial plants.
• Reduction of greenhouse gas emissions: Cogeneration is more environmentally friendly than traditional methods of generating electricity and heat.
• Possibility of integration with renewable energy sources: Cogeneration can be combined with renewable energy sources (RES), such as photovoltaics (PV), which increases its sustainability.

Cogeneration – a step into the future

Cogeneration is not only an efficient way to generate energy, but also a key element in the energy transformation. The use of cogeneration allows for reduced emissions, lower energy costs, independence from external suppliers and integration with renewable energy sources. Hybrid energy systems based on cogeneration and RES are a sustainable and promising alternative to conventional energy sources.

mail: jbigoszewski@eneria.pl

Author: Jakub BIGOSZEWSKI

Product Manager, Gas Turbine Expert