The period 2016 – 2017

An important deliverable is the final Task 1 report including an overview of policies in the various countries and the market developments starting from the existing domestic hot water systems, energy use and use of hot water, toward expected future markets. A scenario has been developed leading to a need for future developments from the smart market perspective of an all-electric society.

Main discussion points for the final Task 1 report:

  • Different available technologies and combination with other technologies. Not only standalone DHW HP’s are into focus, broadening the subject to Sanitary Hot Water.
  • The relation to LT District Heating is especially in focus in some Northern European Countries.
  • Smart Grid solutions and the storage capacities of DHW can be of conflicting interest
  • Legionella and the consequences of the new European regulation under development are an important discussion point. Under Task 1 an overview report will be written.
  • Rating modules and test procedures are not harmonized

An important conclusion is that the use of hot water is a fairly unknown figure, therewith creating uncertainty for the overall design of a domestic hot water system. In most cases it is inevitable that capacities are too large and storage tanks up to 50 – 100% oversized giving unnecessary energy losses and relatively low overall SPF’s. Good and well-designed systems can already have SPF’s of 4.0 for domestic hot water heat pumps.

The final efficiency of DHW HP’s is dependent on more than the stand alone HP itself. Task 2 is focusing on the difference the system configurations on order to be able to give general guidelines for optimization. This approach is based upon an earlier developed methodology by the OA and presented at Montréal.

For Task 3 on modeling two models have become available, where the model delivered by France on stratification is now being tested by the Annex participants. This topic of stratification/thermocline in storage tanks has been a research topic of a number of years already with solar thermal systems, but not so much with heat pumping technologies. At the Heat Pump Conference a number of papers were presented and the participants of the Annex did get feedback as well as on their presentation at Purdue. An overview of models is now being prepared.

An overview of R&D in the participating countries and other non-participating countries like China, Germany. Austria and Sweden is being prepared under Task 4 of the Annex and will be discussed in a workshop in the first half of 2018. Two important levels of R&D are discerned, being:

  • R&D at institutes and universities with a longer term focus and often more fundamental
  • Development with heat pump manufacturers, more focused on the direct and competitive focus of the market needs.

A number of countries, like USA, do have a very focused governmental R&D program on domestic hot water heat pumps.

In relation to the 12th IEA Heat Pump Conference, the Annex 46 participants have proposed and organized a workshop on the combination solar energy and heat pumps related to thermal energy storage. This workshop can be seen as a great added value to the Annex deepening the relation with solar energy. After the Workshop in Rotterdam it became clear that the combination with PV and/or Thermal has a potential which was not fully covered by the former combined SHC/HPT Annex. That Annex focused on heat pumps supporting solar thermal systems as back up heater, by which projects tend to focus on relatively large systems with >1 m3 storage tanks, only applicable in a small number of cases in the market. Main conclusion of the workshop is that there is synergy between Solar and Heat pumps. (without heat pumps solar thermal probably has no future) and that the market is more interested in the PV-HP combination. As this is not the task of Annex 46 a new Annex could fill these gaps.