Cogeneration: A Critical Bridge
to a Sustainable, Net-Zero Future

Buildings and their mechanical systems contribute significantly to global greenhouse gas (GHG) emissions, accounting for approximately 40% of the total emissions. Despite advancements in energy efficiency, mechanical systems — such as boilers and furnaces — still rely on an electricity grid that releases carbon and other pollutants. Furthermore, these power-generating systems often waste ~65% of the energy content of their fuel as heat, which is released into the environment.

However, cogeneration systems, or Combined Heat and Power (CHP) systems, offer a cleaner, more efficient solution. These systems generate heat and power onsite using a single fuel source such as natural gas, biomass, or biogas, and they utilize waste heat that would typically be expelled into the atmosphere. This article delves into the advantages of cogeneration systems, their ideal applications, and how Millig Design Build supports sustainable energy practices.

How Cogeneration Fuels Decarbonization

Cogeneration's efficiency makes it a key technology in decarbonization, particularly in areas where the local electric grid is dirty. These systems allow a facility to replace or supplement grid electricity with its own clean, efficient heat at the point of use. And Cogeneration sets the stage for facilities to reach net-zero carbon emissions. This is achievable because the natural gas a cogeneration system typically uses can be substituted with carbon-neutral alternatives such as hydrogen and biogas.

By utilizing the heat generated during electricity production, cogeneration systems can achieve energy efficiencies of up to 80% or more. This stands in sharp contrast to conventional power plants, which usually attain efficiencies of 35-45% due to the wastage of the majority of generated heat.

Understanding the Benefits of Cogeneration

• Enhanced energy efficiency: By using the heat generated during electricity production, cogeneration systems reach energy efficiencies of 80% or more. Higher efficiency means that less fuel is required to produce the same amount of energy, thereby reducing GHG emissions and reliance on fossil fuels.

• Lowered greenhouse gas emissions: Thanks to their high efficiency, cogeneration systems produce fewer GHG emissions per unit of energy generated. When fuelled by low-carbon or carbon-neutral fuels, these systems can significantly contribute to a net-zero emissions future.

• Decentralized energy generation: Cogeneration systems can be installed at scales ranging from large industrial facilities to small commercial buildings. This decentralized approach to energy generation can decrease the need for long-distance energy transmission, thereby reducing energy losses and improving grid resilience.

• Grid stability and reliability: By providing reliable, on-site power generation, cogeneration systems can bolster grid stability and reduce pressure on the grid during periods of peak demand. These systems can also act as backup power sources during grid disturbances or outages, ensuring energy security and business continuity.

• Integration with renewable energy: As intermittent renewable energy sources like solar and wind power gain more prominence in the energy mix, cogeneration can provide steady baseload power to compensate for these sources' variability. This can facilitate a smoother transition to a higher penetration of renewable energy sources and help balance the grid.

• Economic benefits: By generating both heat and electricity on-site, cogeneration systems can lower overall energy costs.

Ideal Applications for Cogeneration

Cogeneration is particularly suited to applications with simultaneous and continuous requirements for electricity and thermal energy. A typical pharmaceutical plant, for example, runs both chillers and boilers year-round to satisfy the demand for process loads, critical humidity, and space temperature set points. A cogeneration system, powered by clean fuels, can generate CO2-free heat more efficiently than direct conversion of electric power to heat. Other ideal applications for cogeneration include:

• Industrial plants

• Commercial buildings

• Data centers

• Wastewater treatment facilities

• Food processing plants

• Hospitals and nursing homes

• Prisons

• Laundries

• Swimming parks

• Hotels

• Distribution centers

• University campuses

Millig Design Build's Holistic Approach to Decarbonization

At Millig Design Build, we adopt a comprehensive approach to decarbonization. We consider site-specific heat recovery requirements as part of a turnkey solution that can include cogeneration. We believe cogeneration, due to its potential to increase energy efficiency and reduce emissions, is a crucial bridge technology toward a net-zero future.