DH4FREE – Novel district heating solution powered by carbon-free technologies

Challenge
In 2022, Denmark decided to convert 50 percent of the households using natural gas for heating purposes to district heating (DH). On the one hand, currently about 33 percent of the consumers in rural and urban areas in Southern Jutland lacks access to DH networks. On the other hand, a local supermarket is typically situated in the vicinity of these end-users.

Solution
The first goal of the project is to demonstrate a control algorithm that implements an innovative DH solution based on recovering waste heat from local supermarkets. The algorithm will simultaneously optimize the selling of the recovered waste heat and the energy efficiency of the supermarket refrigeration systems.

To further decarbonize Southern Denmark and favor sector coupling, two further control algorithms will be demonstrated, i.e. an algorithm for the optimal use of a cold thermal energy storage (i.e. ice tank) as well as an algorithm for the optimum charging/discharging process of innovative electricity batteries (i.e. vanadium reflux batteries). Such algorithms will allow the supermarket refrigeration systems (and thus the DH generation) to be widely powered through carbon-free technologies, i.e. photovoltaic/thermal (PV/T) solar panels.

Expected result/solution
The results of the project will allow SONFOR to be capable of continuing their strategy of pursuing a greener production mix by decreasing the need for fossil fuel- based production. In addition, the DH4FREE project will enormously favor the spread of next generation electricity batteries, i.e. vanadium reflux batteries, on the part of DanSolar. This could allow the company to become their key manufacturer in the whole Europe.

Furthermore, taking into account that DanSolar has planned to become the first company to manufacture the batteries in Europe (and specifically in Southern Denmark), the region will further become a strategic area as well as the company will additionally become the key manufacturer of the batteries in the continent.

As for Danfoss A/S, the results of the project will allow it to become the first company to have a controller with a dedicated district heating application as well as an algorithm for the optimum ice tank use in the world. Also, the DH4FREE project could open new business opportunities for Danfoss A/S in which PV/T panels and vanadium reflux batteries by DanSolar will be employed.

Finally, the outcomes of the project are believed to draw the attention of several crucial actors in the corresponding sector, such as supermarket chains, district heating companies, end- users, refrigeration system manufacturers, thermal energy storage manufacturers and the national grid administrators/electricity providers.

Problem owner

• DanSolar
• SONFOR

Problem solvers

• Danfoss
• University of Southern Denmark