Umbrella report

IEA HPP Annex 40 Bundesamt für Energie BFE IEA Heat Pump Centre iea International Energy Agency‌

Final Report IEA HPT Annex 40

IEA HPT Annex 40 introduction and projekt outline

Nearly or Net Zero buildings, respectively, are the target in political strategies for the next generation of high performance buildings. Heat pumps are already integrated in building concepts of built nZEB. The energy balance for smaller residential buildings is mostly met by PV-systems, in bigger residential buildings and office buildings, district heating and combined heat and power (CHP) are used as well.

Although there are already several hundreds of nZEB built, most of them are built as prototypes, pilot and demonstration projects with an extensive building technology and partly over-dimensioned building technology and PV-generators in order to meet a nearly zero energy balance and gain experience with the operation of the building or evaluate specific technologies.

Furthermore, there is no consistent definition of nZEB, yet, and therefore, a certain range of ambition levels exists in regard to requirements for generated energy for the balance. Hence, these pilot buildings are not optimised regarding design of the components and cost, and tend to be still expensive buildings due to the use of PV.

As archetype of built nZEB, so called "All Electric Buildings", that only use electricity as delivered energy, have established on the market. The heating systems in these buildings are heat pumps, i.e. heat pumps and PV are already a kind of standard combination.
In Annex 40, heat pump concepts for nearly zero applications were analysed in the framework of case studies and monitoring projects. Moreover, prototype technologies were tested in laboratory and field monitoring and further developed. The results of simulations as well as field experience confirm that heat pumps reach a good performance for the application in nZEB and are favourable regarding to life-cycle cost compared to other heat generator technologies. Moreover, besides household electricity, heat pumps are the biggest electricity consumer in the building, which leads to the opportunity of a higher self-consumption of on-site PV-electricity.

In Annex 40, also development of design tools for heat pumps in nZEB were started, although these developments have not been finished, yet. Furthermore, some development potentials regarding cost-optimised systems as well as improved self-consumptions have been identified. An improvement of on-site electricity use can be achieved by load management and storage integration, which was evaluated by simulations and field measurements. For future building technology an additional criterion may be the possible self-consumption and thereby provided flexibility for the connected energy systems, respectively.

Research of dimensioning regarding the impact on performance, costs and flexibility of the building system technology should assess these aspects to derive cost-optimised system designs, which are also capable to perform system services in order to work in synergy with the connected energy grids. In this sense, the requirements to future system technology may get wider and more complex and heat pumps may also in this respect enable grid-supportive operation due to the link between electric and thermal infrastructure for a flexible operation of the building technology. Under these boundary conditions, an integration of storage systems, with the prognosticated cost degression in the future maybe also electric storage systems, and solar technologies can yield further performance and cost benefits.


IEA HPT Annex 40
Final Report