What improvements do modern heating systems offer?
The era of conventional stoves, furnaces, and boilers will one day be over. Modern heating systems, which are a clever combination of heat pumps, cogeneration units and solar panels, are far more energy-efficient than these conventional systems. They therefore save significant amounts of energy, while at the same time making use of locally available renewable energy sources.
The term “modern heating systems” refers to either heat pumps, small cogeneration units (joint production of heat and electricity, also known as heat-power coupling), or a combination of both. In addition, these systems will increasingly be combined with solar panels (thermal or photovoltaic). The heat produced by these systems is distributed in buildings by low-temperature heat distribution networks (water or air), close to the temperature of the premises to be heated. They also include an air renewal system with heat recovery.
Heat pumps recover renewable heat, which is naturally present in the environment (in air, water or soil). They are now widely used, and their energy efficiency can be improved by another 20 to 30% thanks to technical progress [→ Q59].
Small cogeneration facilities (or “micro-cogeneration units”) for houses or individual buildings are still marginal in Switzerland. These facilities include small natural-gas-fuelled engines with little potential for improvement, or fuel cells with an electrical efficiency 2 to 3 times higher.
They are beginning to arrive in Germany and the United Kingdom from Japan, where more than 100,000 units have already been installed. Fuel cell-based systems have the triple advantage of being quiet, having power-generation efficiencies of up to 50% and having virtually no emissions of pollutants that could affect health. However, despite their excellent energy efficiency, these systems are generally not yet cost-effective [→ Q28].
A particularly effective future configuration consists of coupling a cogeneration unit with a heat pump. Since these are located in different buildings, the electricity supplied by the first is used to power the second. This makes it possible to replace two gas-fired boilers by reducing natural gas consumption - and thus CO2 emissions - by between 40 and 70%, whereas conventional boilers have already reached their maximum efficiency and can hardly be improved.
Increasingly, these heating installations are also coupled with solar thermal panels, in order to benefit from an available renewable resource and thus reduce natural gas consumption. Eventually, as solar photovoltaic panels improve efficiency and reduce costs, thermal solar installations could be replaced by installations that couple photovoltaic panels with a heat pump to produce hot water. Such a solution offers more flexibility by, for example, allowing electricity to be sold to the grid when there is no need for hot water, such as during holiday periods [→ Q50].
- Favrat, Maréchal & Epelly (2008)
- Favrat, D., Maréchal, F. & Epelly, O. (2008). The challenge of introducing an exergy indicator in a local law on energy. Energy, 33(2). 130–136.
- Hart, David and Lehner, Franz and Jones, Stuart and Lewis, Jonathan and Klippenstein, Matthew (E4tech) (2019)
- Hart, David and Lehner, Franz and Jones, Stuart and Lewis, Jonathan and Klippenstein, Matthew (E4tech) (2019). The fuel cell industry review 2018.
- Jochem, Rudolf von Rohr & others (2004)
- Jochem, E., Rudolf von Rohr, P. & others (2004). Steps towards a sustainable development: A white book for R&D of energy-efficient technologies. Novatlantis.
- Pelet, X and Favrat, D and Voegeli, A (1997)
- Pelet, X and Favrat, D and Voegeli, A (1997). Performance of a 3.9 MW ammonia heat pump in a district heating cogeneration plant: Status after eleven years of operation. Compression systems with natural working fluids, IEA Annex, 22.