Project details



Trigeneration systems based on heat pumps with natural refrigerants and multiple renewable sources

Start date: 01.03.2019

Duration: 48 months

Coordinator: Institut für Solartechnik SPF-HSR

Budget: 4.99 M€


The overall goal of the TRI-HP project is the development and demonstration of flexible energy-efficient and affordable trigeneration systems. The systems will be based on electrically driven natural refrigerant heat pumps coupled with renewable electricity generators (PV), using cold (ice slurry), heat and electricity storages to provide heating, cooling and electricity to multi-family residential buildings with a self-consumed renewable share of 80%. TRI-HP systems will include advanced controls, managing electricity, heat and cold in a way that optimizes the performance of the system and increases its reliability via failure self-detection. The flexibility will be achieved by allowing for three heat sources: solar (with ice/water as storage medium), ground and ambient air. The innovations proposed will reduce the system cost by at least 10-15% compared to current heat pump technologies with equivalent energetic performances. Two natural refrigerants with very low global warming potential, propane and carbon dioxide, will be used as working fluids for adapted system architectures that specifically target the different heating and cooling demands across Europe. The newly-developed systems will find application in both new and refurbished multi-family buildings, allowing to cover the major part of Europe’s building stock. The new systems reduce GHG emissions by 75% compared to gas boilers and air chillers. The TRI-HP project will provide the most appropriate knowledge and technical solutions in order to cope with stakeholder’s needs, building demand characteristics, local regulations and social barriers. Two system concepts will be developed for two different combinations of heat sources, i) dual ground/air source and ii) solar with ice-slurry as intermediate storage. These two concepts combined with the two heat pump types developed (CO2 and propane) will lead to three complete systems (CO2-ice, propane-ice and propane-dual) that will be tested in the laboratory.

List of achievements

The project public deliverables are available here.


Contact person: Dr. Daniel Carbonell
Address: SPF-HSR, Oberseestrasse 10, CH-8640 Rapperswil
email: contact form: