This fact sheet on new technologies around district heating and cooling summarizes some facts deemed significant by our Fellows as part of the Presans Platform activity.
The first urban heating and cooling networks date back to the Roman Empire.
In the context of current policies to reduce greenhouse gas emissions and improve the efficiency of heating and cooling systems, the theme of urban heating and cooling networks is important. Cities are indeed the best place to implement synergies. In fact, urban areas have a growing heterogeneity in terms of energy needs:
- High heating requirement for most old buildings (50 ° C)
- Lower need for renovated and new buildings (35 ° C)
- Modernization rates still modest
- Some special sites have very high needs (hospitals)
- Hot water preparation is a significant part of the need
Urban heating networks have been in use for decades to meet these needs:
- They represent 10% of the heat consumed in Europe
- They allow large-scale use of efficient energy conversion technologies
However cooling needs increase. In addition, the efficiency of decentralized heat pumps is progressing. Finally, urban structures limit the maximum size of pipes that can be used.
2. Established actors in the sector
The main companies in heating and district cooling include:
Engie (France); Veolia (France); NRG Energy (USA); RWE (Germany); Vattenfall (Sweden); Danfoss (Denmark); Fortum (Finland); Statkraft (Norway); Alfa Laval (Sweden); Korea District Heating Corporation (South Korea); SSE (UK); Radet (Romania); FŐTÁV Zrt. (Hungary).
These companies operate networks based on first, second or third generation technologies:
- First generation (1880-1930): still used in Paris, this type of network consists of steel pipes passing through the concrete and carrying water vapor. Its energy efficiency is low.
- Second generation (1930-1970): the network transports pressurized water and uses fossil fuels as a source of energy.
- Third generation (1970-2020): pre-insulated pipes; compact distribution stations, also connected to renewable energy sources; measurement and monitoring systems.
The trend is to increase energy efficiency, and thus reduce the heating temperature required to operate the system.
3. New technologies for smart cities
New heating and cooling technologies aim to optimize synergies through advanced urban networks, and by adopting innovative approaches in the field of gas conversion (fossil or renewable).
In concrete terms, the profile of the following generations of networks is as follows:
- Fourth generation (under development): highly integrated four-pipe system for heating and cooling, smart metering and multiple integrations with renewable energy sources.
- Fifth generation (under development): two-pipe, low-temperature system for free-cooling coupled with heat pumps, smart meters, multiple integrations with renewable energy sources and waste heat recovery plants .