Utilizing Excess heat from a Supermarket Refrigeration System in a District heating Grid as part of a Smart Energy System XIX INTRNATIONAL CONFERENCE ON DISTRICT ENERGY Portoroz 20-22 March 2016 Jan Eric Thorsen Danfoss A/S Heating Segment Application & Technology Torben Green, Torben Funder-Christensen Danfoss A/S Cooling Segment Denmark

Content Supermarkets as smart appliance Flexibility in supermarkets Aggregated potentials Thermal networks Case study on District Heating connectivity Unused compressor capacity is an opportunity Conclusion This presentation is about the smart grid opportunities for a combined heating and refrigeration cycle applied in food retail applications. The potential of adding the flexibility of supermarkets to a smart grid network is outlined as well as the potential of utilisation of unused compressor capacity. In connection with external thermal networks a functional storage opportunity for renewable energy sources like wind is shown viable and backed up by a new case study. The business implications of connecting the supermarket to the district heating are briefly outlined.

Supermarkets as a smart appliance Exploiting flexibility is doable without big investments The existing retail service structure is perfect to leverage on Exploiting flexibility is doable without big investments The existing retail service structure is perfect to leverage on

Flexibility in supermarkets

Flexibility characteristics

Aggregated flexibility potentials Supermarkets use up to 2% of all electricity use for compressor corresponding to 10 TWh in GER, 2012, 36.000 outlets, 32 mill. m^2 Flexibility of multiple supermarkets can be aggregated, and adressable Total supermarket aggregation in GER would account for > 15 % of average delivered wind power (57,4 TWh/2014) in GER > 25 % of average delivered PV power (36,1 TWh/2014) in GER

Thermal networks expand the perception of smart systems and the scope for supermarkets “Waste” or excess heat and cooling from refrigeration can be exported Supermarkets can add flexibility and become storage enablers for heating and cooling

In the perspective of DH development District heating networks can absorb and store fluctuating energy Typically only 30% of the total compressor capacity is used Assumingly a factor 2 more energy can be produced with external heat sources

Case study on District Heating connectivity Southern Denmark Area: 1000 m2 from 2010 Compressors: 5 MT (1 VS), 4 LT Cooling Capacity: 160 kW Online COP calculation Heating : Sanitary water (1.8m3 ,65 oC) Space heating/low temp (35 oC ) District Heating connection Flow line temp. 65 oC Return line temp. 35-40 oC Online COP to ensure that only real waste heat is produced

Outline of system concept DH from return line DH to flow line Space heating water loop

Results The heat loss is 65 % of the total heat energy The heat loss is expected to be 35 % when space heating cut in at low ambient temp. Average export of DH heat is 27 kW at 65 °C . (This can be regarded as an average for the year, Summer ~40 kW / winter ~15 kw) Yearly DH income to the supermarket is estimated to be 6000€ (24€ per MWh) Accumulated Energy exported to the DH grid MT cooling contains LT energy. But it not contain the MT compressor energy. MT + Compresso energy will be approx. 1,3*78 = 101 kW DH heat + Heat loss to ambient is = 30+65 = 95 kW. Difference is heat lost in machine room + small amount of space heating (T-amb was 8 degrees in week 15 in SDBG airport)

Conclusion Supermarkets: can play a significant role in smart and integrated energy systems are addressable flexibility resources require modest investments before they make up a good business case Heat recovery is taken to the next level by connecting DH grids to the supermarket refrigeration system Extended heat and cooling production can be utilised once connected to the DH grids Thermal and Electrical Flexibility can enforce each other providing a multiplier factor for the business case

Thank You for the attention Jan Eric Thorsen jet@danfoss Thank You for the attention Jan Eric Thorsen jet@danfoss.com Danfoss A/S Heating Segment Application & Technology