How Cogeneration Works: A Step-by-Step Explanation
If you’re an energy producer, you want to generate power as efficiently as possible. Wasted energy is your enemy. One efficiency solution that continues to be a thoughtful approach for large power consumers is cogeneration, also known as Combined Heat and Power (CHP). It’s likely many people are unfamiliar with this concept so have no fear. This CHP 101 blog post will walk you through what a cogeneration system is, how these systems work, and the benefits that may offer.
What is Cogeneration?
Cogeneration, aka CHP, is an energy production process that maximizes output and minimizes energy losses from a single fuel source. This process produces both electricity and thermal energy simultaneously, making it a more efficient process than if the thermal energy were wasted.
What’s fascinating about cogeneration is that traditional central power plants are roughly 30% efficient at converting a fuel source to electricity while cogeneration plants are roughly 70-90% efficient at performing the same task. Said another way, central power plants waste 70% of their energy while cogeneration plants waste ~10-30% of their energy.
How Cogeneration Works
At its core, cogeneration is all about efficiency. Here's generally how the process of cogeneration works:
One Fuel, Multiple Benefits: Cogeneration only uses one fuel source, such as natural gas, biomass, or biogas.
Electricity Generation: This fuel power is a prime move, which can be a reciprocating engine, turbine, or fuel cell. Prime movers convert chemical energy into electrical energy.
Heat Recovery: But here's where the magic happens. Cogeneration doesn't stop at electricity. It captures the waste heat generated during the electricity production process, heat that would otherwise be released into the atmosphere.
Utilizing Waste Heat: Instead of wasting this valuable heat, cogeneration puts it to work for heating, cooling, hot water, and industrial processes. It's a dual-purpose energy generation process at its finest.
Benefits of Cogeneration
The advantages of cogeneration can make it an excellent choice for a range of applications and industries:
Energy Efficiency: Cogeneration systems are incredibly efficient, converting 70-90% of the energy in the fuel into useful energy. Compare that to conventional power plants, which often waste more than two-thirds of the energy during production and transmission.
Economic Savings: By using the same fuel for both electricity and thermal energy, cogeneration can reduce overall energy costs. The initial investment in a cogeneration system can be recouped through operational savings.
Energy Resilience: Cogeneration systems ensure energy resilience, allowing facilities to function even during grid outages, a vital feature for critical infrastructure like hospitals or universities.
Distributed Generation: Unlike conventional centralized power plants, cogeneration systems are typically located on-site or nearby, reducing energy losses during transmission and distribution.
Exploring Cogeneration Systems: CCHP and District Energy
While cogeneration primarily focuses on combined heat and power (CHP), there's an extended version known as Combined Cooling, Heating, and Power (CCHP). CCHP takes the concept a step further by simultaneously producing cooling alongside electricity and heat.
Cogeneration also plays a pivotal role in district energy systems. District energy leverages cogeneration to provide heating, cooling, and power to a cluster of buildings or an entire district. This approach optimizes energy efficiency and reduces waste.
Cogeneration and the Future of Sustainable Energy
The benefits of cogeneration, which include energy efficiency, cost-effectiveness, and energy resilience can make it an attractive option for critical facilities like hospitals as well as large commercial and industrial consumers like universities and manufacturing plants.
In summary, cogeneration, or CHP, is an efficient way to produce and use energy. By utilizing waste heat, cogeneration increases efficiency and can reduce costs. As power markets continue their energy transition, cogeneration can be a solution to consider for energy consumers that need onsite generation.
