In the world of energy there are various ways in which to produce electricity. It can be used fossil fuels (oil, coal, natural gas…) to produce electricity in many ways. The problem with using them is the pollution they generate and that they are limited resources. We can also obtain energy through renewable sources such as solar, wind, geothermal or hydraulic, thus taking care of the environment since these are inexhaustible.
Regardless of the energy source used, efficiency is paramount in energy production systems. The greater the energy efficiency, the better we will use resources and generate a greater amount of quality energy. A system that stands out for its high efficiency is the cogeneration.
What is cogeneration?
Cogeneration is a highly efficient energy production system, which simultaneously generates electrical energy and thermal energy, making the most of the primary energy used, which normally comes from the combustion of fossil fuels such as natural gas or oil.
This process is much more efficient than conventional generation systems, as it not only produces electricity, but also uses the heat generated during the process, which would otherwise be wasted. This translates into a significant improvement in the use of natural resources.
Advantages of cogeneration
The main advantage of cogeneration is its high energy efficiencyBy harnessing heat to generate thermal energy, the need for additional installations such as conventional boilers is avoided. This means that instead of managing two independent systems (one to generate electricity and another for heat), cogeneration solves both needs in a single process.
Another important benefit is that cogeneration can be done close to the point of consumption, reducing energy losses in transport. These losses, which in conventional electricity networks can range between 25% and 30%, are significantly reduced in decentralized cogeneration systems.
In environmental terms, greater efficiency also translates into a reduction in CO2 emissions and other polluting gases. If the waste heat is also used for cooling (cogeneration), efficiency is further optimised.
Elements of cogeneration
The cogeneration system is made up of several elements that work together to achieve its high performance:
- Primary source of energy: They are generally fossil fuels such as natural gas, although biogas or biomethane can also be used in specific applications.
- Mechanical energy transformer: Gas turbines, steam turbines or reciprocating engines convert the chemical energy of the fuel into mechanical energy.
- Heat utilization: Boilers, heat exchangers or dryers recover the heat generated in the process.
- Refrigeration system: When part of the thermal energy is not used, a cooling system is used (cooling towers or air condensers).
Types of cogeneration plants
There are several types of cogeneration plants depending on the elements they use to transform primary energy:
- Gas powered plant: They use natural gas, diesel or fuel oil. They offer high efficiency in the production of electricity, but are less efficient in the production of heat.
- Gas turbine plant:The thermal energy of the exhaust gases is easily recovered, which can be used to produce steam.
- Steam turbine plant: It uses the expansion of high-pressure steam to move turbines and generate electricity.
- Combined cycle plant: It uses both gas and steam turbines to improve the overall efficiency of the process.
Cogeneration benefits
Cogeneration generates a series of benefits that can be grouped into three main categories:
- Benefits for the country and society: Saving primary energy, reducing polluting emissions, job creation and regional development.
- Benefits for the user: Greater efficiency, reduced energy costs, compliance with environmental regulations and increased industrial competitiveness.
- Benefits for the electric company: Avoids energy transmission and distribution costs, and improves electricity supply planning.
With its ability to generate electricity and heat simultaneously, cogeneration remains a key option in the development of sustainable energy technologies. The possibility of reducing emissions, lowering energy costs and increasing efficiency make this system a comprehensive solution for industries, homes and even urban centers with high energy demand.