Cogeneration refers to the combined generation of heat and power. With CHP, generation occurs close to the site of consumption, easing the burden on the power grids. Its high flexibility also ensures stable power generation, even when there is no wind or the sun is not shining. In contrast to conventional centralized and fossil-fuelled steam power stations, production from CHP plants can be easily capped or the plants can be shut down entirely, if necessary. So, CHP technology fits perfectly in the existing infrastructure of electricity, heat and gas grids in Europe.
Thanks to their flexibility and their optimal use of renewable energy, for instance: in the form of biomethane, hydrogen or other synthetic fuels, CHP plants are well-suited to cover residual loads in the power grid. All of these factors make CHP plants an important element of the energy supply of the future and an ideal member of the renewable energy technology family.
Advantages of cogeneration
COGEN Europe promotes the expansion of CHP across Europe. The association advocates for sector coupling and considers CHP to be the backbone of the future European energy system – carbon neutral, decentralized and resilient.
Detailing on the merits of cogeneration, Hans Korteweg, CEO, COGEN Europe, said, “CHP has the potential to bring together the electricity, heat and gas grids. It efficiently integrates renewable energy and its use for decarbonized energy supply. CHP thus brings more reliability and flexibility to the energy system by being able to generate heat and electricity at all times. The combined generation of electricity and heat is more cost-effective, more efficient and also leads to lower emissions.”
Image © Wärtsilä Corporation
Role of green H2 in energy storage
CHP must be viewed in combination with renewable energies in sector-coupled, integrated solutions. Its potential can be seen in Power-to-Fuel technology, where excess renewable energy is converted to hydrogen or another type of synthetic fuel. This technology allows energy to be stored and transported cost-effectively.
Explaining the future potential of CHP generation, Jan Andersson, Market Development Manager of the Finnish company Wärtsilä, said, “With the stored fuel, thermal CHP plants produce electricity on days without wind or sunshine. These plants ensure stability by feeding additional electricity into the grid when needed. Thanks to Power-to-X technology, CHP plants will play an important role in the energy supply of the future.”
As one of the leading energy system integrators, Wärtsilä has commissioned numerous CHP plants in Germany, including the new CHP plant for the municipal utility company Kraftwerke Mainz-Wiesbaden (KMW), which has an output of more than 100 megawatts (MW). Wärtsilä’s gas motors make up the central element of the power plant. The CHP plant has been designed to serve as a reliable source of power for around 40,000 households in the Mainz-Wiesbaden region, outputting 100 MW of electrical power and around 90 MW of thermal power. The plant has been officially handed over for commencement of commercial operations in April this year.
Contextually, as part of its climate action plan, the German government has committed to increasing the share of electricity produced by CHP plants to 25% of the total electricity production by 2025. Germany, like the European Union, aims to become greenhouse gas neutral by 2050. It has set the preliminary target of cutting emissions by at least 55% by 2030 compared to 1990 levels.
Virtual power plants play an important part in providing control reserve from renewable energies such as biogas, Power-to-X and CHP plants. Citing an example of the utility of CHP plants, Jochen Schwill, Founder and CEO of Next Kraftwerke, said, “CHP plants can help balance out fluctuations caused by volatile renewable energy by feeding power into the grid, producing either more or less electrical energy at short notice. To this end, we provide local forecasts of the generation of energy from renewable sources and the utilization level of the natural gas grid. Together with the operators, we then sell the flexibility offered by CHP plants on the electricity balancing market for a profit.”
CHP and hydrogen
The key technologies for electrification and renewable energy production are consistently becoming more cost-effective and enabling a transformation of power supply towards a decentralized structure. This development is a much stronger driver for the decarbonization of the energy system than the time-consuming expansion of large infrastructures. CHP plants are increasingly being fuelled by green hydrogen, and comprehensive sector coupling is being used to supply districts as climate-neutrally as possible. CHP is hydrogen-ready according to the reports from the Bundesverband Kraft-Wärme-Kopplung (B.KWK), Germany’s Federal Association for CHP Systems. Operating plants with mixed gas containing a 10% hydrogen admixture is no problem for modern CHP plants. Pure hydrogen can be used in fuel cells and there are already some CHP plants that can run on 100% hydrogen.
