Cogeneration is a system that produces heat and electricity simultaneously in a single plant, powered by just one primary energy source, thereby guaranteeing a better energy yield than would be possible to achieve from two separate production sources. In this way, nearly all the thermal energy produced by combustion processes is not dissipated into the environment, as happens with traditional plants, but is recovered and reused. The most widely used cogeneration technologies involve the combustion of fuels such as natural gas, GPL, diesel, biogas, bio-methane, vegetable oil or biomass.
What are the benefits of cogeneration?
A cogeneration system (also called a Combined Heat and Power system, or CHP), can deliver significant benefits for commercial and industrial (C&I) customers, because it produces heat and electricity at the same time. Using the same fuel to generate both heat and electricity therefore improves energy efficiency, delivers environmental benefits and ensures savings. Cogeneration power plants generally operate at between 50 to 70% higher efficiency rates than traditional power plants. The European Union has incorporated cogeneration into its energy policy aimed at reducing greenhouse gases and becoming carbon neutral by 2050. Cogeneration accounted for 12% of Europe’s electricity production and 14% of its heat in 2019, according to Eurostat figures, and COGEN Europe estimates that number could increase to 20% of electricity and 25% of heat by 2030.
Cogeneration systems can:
- Improve the overall efficiency of energy usage by combining the production of heat and electric energy in a single generator
- Reduce energy costs
- Lower emissions
- Reduce risks of power cuts due to grid problems
- Qualify for economic incentives relating to energy efficiency projects
- Use renewable energy sources like biomass
- Be adapted to fit the needs of all sorts of users, including residential
- Reduce reliance on energy grid, since a CHP is usually onsite or nearby
- Promote energy self sufficiency and reduce energy imports
How do cogeneration systems work?
Conventional power plants generate electricity by heating water to the boiling point, thereby producing steam to drive a turbine that creates kinetic energy needed for electricity. The water is usually heated by using a fossil fuel like coal, oil, or natural gas. Energy is wasted in every step of this process, particularly because the heat generated to create steam is simply released into the atmosphere. Some 60% of energy can be wasted during traditional electricity generation.This means that energy efficiency runs at about 30%, because some of the energy dissipates during transmission. Instead, a cogeneration plant captures and uses this heat by, say, piping the hot water and suppliers it to a consumer (be it a factory or a group of buildings). Therefore the cogeneration benefits mean that only 10%-30% of energy is wasted, meaning that energy efficiency improves to 70%-90%.