What is cogeneration and why should you implement it in your company?

Cogeneration can use various energy sources. The most common is gas-fired cogeneration, which is based on natural gas. It is one of the most efficient and environmentally friendly solutions because natural gas is characterized by low pollutant emissions. Another type is solid fuel-based cogeneration, such as coal, biomass, or waste. This solution varies more in terms of environmental impact, depending on the fuel used, and is generally less efficient. There is also liquid fuel-based cogeneration, most commonly using heating oils. This option is less popular due to higher costs and greater pollutant emissions.

This article focuses on high-efficiency gas cogeneration, which offers the greatest benefits among the types listed above. A cogeneration unit consists of two main components: a drive device and an electric generator. The drive device can be an internal combustion engine (e.g., a popular diesel engine adapted to burn gas) or a gas turbine. In both variants, the drive powers the electric generator. Its electric output typically represents 40–45% of the rated power of the engine or turbine. The heat production efficiency of the entire cogeneration system is about 45%. To achieve this high level, heat recovery systems are used—from the engine jacket (temperature about 80–90˚C) and from exhaust gases (temperature 300–600˚C).

The use of cogeneration systems—i.e., the combined production of electricity and heat—brings a dual benefit, as the name implies. First and foremost, it significantly increases energy efficiency by using heat that would otherwise be wasted in traditional power plants. The cogeneration process involves the beneficial use of heat generated during the production of electricity in a gas engine.

This enables companies to significantly reduce their energy bills, which translates into lower operating costs. Additionally, cogeneration contributes to reducing CO₂ emissions, which is especially important in the context of increasing environmental requirements. Moreover, such a system can easily be powered by biogas/biomethane, allowing the generation of green energy with high efficiency. Another advantage is greater energy independence, as companies that produce their own energy are less reliant on external suppliers, which increases their energy security. Companies using cogeneration become partially independent from the grid electricity supply.

A typical cogeneration system with a capacity of up to 1 MW does not require much space. The entire unit (drive and generator) can be housed in a soundproof container measuring approximately 3x12 m. This same container also contains auxiliary installations such as electrical switchboards, heat exchangers, and coolers, which maintain the proper engine temperature in case of low heat demand.

One of the main challenges related to cogeneration is the high initial cost of installing a cogeneration unit, which may be a barrier for some companies. Additionally, cogeneration requires advanced technology and proper management, which can be a challenge for enterprises without sufficient technical capacity. Careful planning and optimal system alignment with the specific nature of the business is also crucial to fully benefit from cogeneration.

Cogeneration works best in companies with consistent and high demand for electricity and heat. Examples include industrial plants with significant thermal energy needs, such as the chemical, food, or paper industries. Cogeneration units are particularly suitable for companies that use both hot water and steam to power their technological processes.

Trigeneration is an extension of the cogeneration concept that involves the simultaneous generation of electricity, heat, and cooling. It is particularly beneficial in places with high cooling demand, such as data centers, commercial facilities, or hotels. Trigeneration allows for even greater energy efficiency and financial savings.

Combined heat and power generation, or cogeneration, is a forward-thinking solution for industrial companies seeking to improve energy efficiency and reduce operating costs. Thanks to its efficiency and environmental friendliness, gas cogeneration is one of the best available options. Despite certain challenges related to installation, the benefits of this system clearly outweigh the drawbacks. If your company needs stable and efficient energy sources, it is worth considering the implementation of a cogeneration system.