18 May 2017

O.2.6.2 Practical experience on tendering and contracting heat pumps for district heating

The Danish Energy Agency has recently subsidized 10 demonstration projects to push the utilization of heat pumps for district heating. This takes the total number of heat pumps in Danish district heating to around 30. The focus is on heat pumps that utilize ambient heat sources to enable stand alone operation with output temperatures between 70-75 °C. The units must consist of commercial available components with no R&D elements as this will ensure swift installation. Sizes range from 0.8 to 4 MW thermal and the funding was pledged late 2015. The demonstration plants will be put into operation from late 2016.
The engineering company PlanEnergi is currently client advisor on 6 heat pump projects. This presentation will discuss tendering and contracting based on practical experience. As annual operating hours are high and the primary operating cost is caused by electrical consumption, high efficiencies are key for profitable plants. This has to be evaluated relative to installation cost and complexity, and must be included in the tendering documents. Small deviations in performance have a great impact on the total economy and adequate performance acceptance tests are vital. Existing test standards are not applicable as tolerances are too high and new methods have been developed to allow fair and accurate onsite performance evaluations in conditions that may differ from the tender. The developed performance test only allow small deviations from guaranteed performance as well as remedies and bonus terms for the supplier.