Peter Op ‘t Veld, Bert Gilissen Huygen Engineers & Consultants Maastricht, the Netherlands

1. The Mine Water Project in Heerlen the Netherlands: development of a geothermal mine water pilot towards a full scale hybrid low exergy infrastructure Peter Op ‘t Veld, Bert Gilissen Huygen Engineers & Consultants Maastricht, the Netherlands

2. Content • Mine Water Project as a pilot (1.0) • Boundaryconditions buildings • Transitition to a versatileexergybasedenergyinfrastructure (2.0) • Furtherdevelopments and research • Conclusions

4. Distribution:Low temperature (‘lowex’) H&C distribution systemthe primary gridmine water 1.0 – started as a pilot in 2005

5. Heerlerheide Buildings Heerlerheide Centre H C R 170C 20…240C 35…400C Energy station Heerlerheide Centre 2 Warm Wells HP HP Option: Regeneration of wells (by HP’s in buildings) 280C Intermediate Well 16…180C Heerlen CBS - APG - ARCUS Energy stations buildings 2 Cold Wells Energy stations buildings Energy stations buildings

6. From a schematic approach to a LT H&C grid in practiceLength 7 kmSome decision parameters: • Length op the grid • (Type of) paving • Drillings (road crossings) • Existing infrastructures • Impact on wells • Flow directions • Ecology • Archaeology • Soil (pollution) • Permits • Costs

7. Demand side: the buildings current connections to the grid

8. Heerlen location – Heerlerheide Centre(2005 – 2012) • Location Heerlerheide Centre • 312 apartments • 3800 m2 commercial buildings • 2500 m2 public and cultural buildings • 11500 m2 health care buildings • 2200 m2 educational buildings • Energy station

9. Heerlen Centre ABP building: retrofitting, office 40.000m2 Retrofittingcompleted, connected2013 CBS building: new office, 21.000m2 Completed and connected 2009 Arcus College: new school, 25.000m2 Completedand connected2014

10. Boundary conditions: What is “extra” needed to make a building minewater proof/lowex (NL)?See also IEA EBC Annex 49: www.annex49.info Building Reg’s NL Thermal insulation Envelope U = 0.37 Glazing U = 3.0 Ventilation No system requirements Air tightness n50 = 3 Emission system No requirements HVAC system/efficiency No requirements (but in EPR) Energy Performance (EPC) dwellings 0.6 Practice 2014 NL Thermal insulation Envelope U = 0.26 Glazing U = 1,2 – 1,5 Ventilation 50% ME/50% MVHR Air tightness n50 < 2 Emission system Radiators HVAC system/efficiency Condensing boilers η = 95% No cooling EPC dwellings 0.6 Mine water Lowex Thermal insulation Envelope U < 0.25 Glazing U < 1.2 Ventilation MVHR η = 95% Air tightness n50 <1 Emission system Floor heating and cooling HVAC system/efficiency Mine water with heat pumps (boiler back up) Sustainable cooling EPC dwellings < 0.5

11. LowEx direct heating and cooling

12. Indirect heating and cooling

13. Optimization by using Load Duration Curves • Dynamical buildings simulations (by TRNSYS) • Temperature levels for heating, cooling and DHW • Ratio RES (and HP) and conventional • Balancing H and C storage • Optimization transmission and ventilation losses and seasonal operation • Enlarging the ‘dead-zone’ = period without H or C demand > conflict with energy exploitation and economical feasibility! (decrease of energy demand = decrease of profits)

14. Optimizing ratio RES/conventional by using a LD curve (location Heerlerheide) dead band

15. Towards Mine Water 2.0: Long term maximum use of geothermal underground for sustainable heating and cooling of buildings • Energy exchange instead of energy supply: • Between buildings by cluster grids • Between clusters by the mine water grid • Using Exergy Principles • Energy storage and regeneration of mine water reservoirs instead of depletion • Enlargement hydraulic and thermal capacity mine water system • Fully automatic control and demand driven: heat and cold supply at any time • Addition of poly generation like Bio CHP, reuse of waste heat (data center; industry), closed greenhouse, cooling towers etc. • > The mine water energy supply is the backbone for this

16. Towards Mine Water 2.0 CLUSTER D Componenta-Otterveurdt Return well HLN3 out of order Hot to Hot (HH2) Cold to Cold (HLN2) Thot supply 28˚C Tcold supply 16˚C Thot return 28˚C Tcold return 16˚C HH1 Cluster grids Injection wells HH2 and HLN2 bidirectional HLN1 HLN3 HH2 CLUSTER A Arcus-APG CLUSTER C Weller HHC CLUSTER B CBS-Maankwartier HLN2

17. Example ‘Cluster D’ CLUSTER D Componenta-Otterveurdt

18. Cluster D (north west Heerlen) • Connections: • Ironfoundry (industrial waste heat supply) • Swimming pool • Retail store • Community building/school • ‘Hooveringgrid’: gridwithflexibletemperatures • Heat: 29 – 500C • Cold: 15 – 200C • Localstorage at user level • Reductioncapacity heat pumps in buildings • Reducingconnected power, allowing more customerson the grid • Dealingwithdailyfluctations H&C demand (day T amplitude)

20. Schemeforstandardizedsolution in cluster grids DHW Storageforday amplitude Heat exchangers Heat pump(s) End user Building energy station Mine water energy station Cluster grid

21. Further R&D towardsgeneralapplication in lowexinfrastructures(TKI LowEx OLEC and IEA Annex 64)

22. Further R&D towards general application in lowex infrastructures

23. Conclusions • The Mine Water project in Heerlen upgraded from a pilot system to a smart grid in heating and cooling with full scale hybrid sustainable energy structure (Mine Water 2.0) • Cluster grids are a profound exergy based solution to provide energy exchange between buildings and use of waste heat • By poly generation and the application of cluster grids the capacity of the mine water grid can be strongly increased • Cluster grid applications are used in combination with low temperature geothermal sources (mine water) and can be applied in general with other sustainable heat and cold energy sources (e.g. waste heat from data centres and closed greenhouses) • Mine Water 2.0 proves that heat pump operation with low-ex heat sources can be commercial feasible • The technologies are general applicable for all types of exergy based energy infrastructure systems • It is the Quality of Energy and its Management that counts!