The Final Report for HPT TCP Annex 45 – “Hybrid Heat Pumps”, has been finalized and can be downloaded at the Annex 45 web site: https://heatpumpingtechnologies.org/annex45/
You can also download the 2-page summary here.
The main objective for the Annex has been to investigate the potential of energy and emission of greenhouse gasses emission reduction by the increased implementation of hybrid heat pumps. Both through replacement of boilers, and by means of upgrading the systems’ efficiency in existing running installations. The focus Annex 45 has been on the residential sector, as well as the light commercial sector, where the market overview shows potential.
Annex 45 made clear that hybrid heat pumps, driven by fossil fuels and electricity, may serve as a gateway to low-carbon heating. Once the user is used to the heat pump functionality, it should be easier to take the step to all-electric heating with a standard heat pump.