Shallow Geothermal Energy for Heating and Cooling of larger buildings in commerce, offices, tourism Dr. Burkhard Sanner VDI, Giessen, Germany

Laying the ground: - Some statistics on GSHP in Germany - German standards and guidelines for GSHP Heating and Cooling with GSHP: - Principle and development - Various smaller examples - Example Leica Wetzlar (BHE) - Example Bonner Bogen (wells) Conclusions

Total number of installed, operational ground-source heat pumps Calculated after data of BWP

Avoided CO2-emissions thanks to ground-source heat pumps Calculated after data of BWP

Europe, installed capacity per country as of 2013 From EGEC Market Report 2013/14, update

Annual sales of ground-source heat pumps since 1978 and some events influencing this development After data of BWP

Annual sales of ground-source and air-source heat pumps After data of BWP

DIN EN 15450 (2007-12): “Heating systems in buildings - Design of heat pump heating systems” (German adaptation of EN 15450) EN 15450 elucidates the basic problem for a geothermal standard on a European level, i.e. the variations in climate, geology, traditions in construction. As a result, it can only give a general minimum framework for design and installation, with many items to be filled in locally or regionally

DIN 8901 (2002-12): “Refrigeration systems and heat pumps – protection of soil, ground and surface water” Deals with safety aspects of the heat pumps, in particular for use with groundwater as heat source/sink, and for direct expansion ground coils

VDI 4640 „Thermal Use of the Underground“: Part 1: General Issues / Licenses / Environment, revised 2010-04 (draft published 1998, original 2000-12) Part 2: Ground Source Heat Pumps, 2001-09 (original draft published 1998, draft of revised text 2015-05) Part 3: Underground Thermal Energy Storage (UTES), 2001-06 (revision ongoing) Part 4: Direct uses, 2004-09 (revision started) Part 5: Thermal Response Test, draft expected fall 2015 Covers all relevant aspects in very comprehensive way Started in 1995 following an initiative from the geothermal sector Elevated shallow geothermal from scratchbuilding to industrial product !

VDI 4640-2, draft 2015-05 groundwater wells as heat source/sink horizontal ground collectors borehole heat exchangers (incl. heat pipes) special issues for direct expansion systems other ground heat exchange devices (energy piles and concrete parts, tunnel walls, compact ground collectors) system integration issues related to the heating system materials for ground heat exchange devices measures in case of system failure, de-installation

Chapter 7 on borehole heat exchangers, systems <30 kW VDI 4640-2, draft 2015-05 Chapter 7 on borehole heat exchangers, systems <30 kW Basic load profile for tables on specific heat extraction

Chapter 7 on borehole heat exchangers, systems <30 kW VDI 4640-2, draft 2015-05 Chapter 7 on borehole heat exchangers, systems <30 kW Target temperature values and formula for tables on specific heat extraction Minimum temperature from heat pump: for base load ≥ 0 °C for peak load, three scenarios: ≥ -5 °C, ≥ -3 °C, ≥ 0 °C Maximum temperature from heat pump / system: - in cooling mode ≤ 20 °C

Chapter 7 on borehole heat exchangers, systems <30 kW VDI 4640-2, draft 2015-05 Chapter 7 on borehole heat exchangers, systems <30 kW Example of tables on specific heat extraction

Chapter 7 on borehole heat exchangers, systems >30 kW VDI 4640-2, draft 2015-05 Chapter 7 on borehole heat exchangers, systems >30 kW Individual calculations or simulations are required Possible methods: analytical solutions (heat transfer calculation) nomograms or simplified calculation methods simulations using approximative functions numerical simulations

DVGW (German Water and Gas association) guidelines for certification of drilling companies: DVGW W120-1 „Qualification requirements for drilling technology, well construction, rehabilitation and de-installation“, 2012-08 DVGW W120-2 „Qualification requirements for drilling technology and shallow geothermal energy (borehole heat exchangers)“, 2013-07 These guidelines set the requirements in equipment and skilled personal for certification of drilling companies Virtually all construction licenses for shallow geothermal installations in Germany require the drilling company to be certified

While heating demand will decrease in the EU, cooling demand is expected to increase further Graph from the Common Vision of the RHC-Plat-form, 2011 www.rhc-platform.org

Cooling in shallow geothermal installations can be achieved in different ways: Running the heat pump as cooling machine (either by changing refrigerant flow or by external hydraulics) Using the ground directly for cooling (as long as supply temperatures from the ground are low enough) Combination of the two methods mentioned above Dedicate cold storage in the ground (lowering the ground temperature in winter intentionally, e.g. by air coolers)

Already an early (probably the first) GSHP in the USA used heating and cooling, Indianapolis, 1945 Heat source and –sink: - horizontal coils in trenches - direct expansion Winter, heating Figure from Crandall (1946)

Already an early (probably the first) GSHP in the USA used heating and cooling, Indianapolis, 1945 Heat source and –sink: - horizontal coils in trenches - direct expansion Summer, cooling Figure from Crandall (1946)

First practical application of direct cooling from the ground in Europe, using closed-loop BHE, at Helmut Hund GmbH, Wetzlar, 1987 Figure published at IEA Heat Pump Conference Tokyo 1990 (from Sanner , 1990) Winter, heating Summer, cooling

Small optical factory with cooling of dust-free rooms (almost all year round) in Rathenow, 1992 Figure from Sanner (1993)

Office building VIKA in Aachen, 2003 28 BHE each 43 m deep Heating and cooling through pipes in floor/ceiling slabs Very well suited for direct cooling from the ground Graph and photos VIKA / EWS

Heating and cooling with GSHP works far North: Location: 65°51’ N Heating and cooling with GSHP works far North: Hotel Storforsen in Bredsel, Älvsbyn, Sweden 33 BHE each 160 m deep Hotel Storforsen on the Pite river (Piteälv)

Heating and cooling with GSHP works far North: Location: 65°51’ N Heating and cooling with GSHP works far North: Hotel Storforsen in Bredsel, Älvsbyn, Sweden

Heating and cooling with GSHP also works in the South: Location: 37°40’ N Heating and cooling with GSHP also works in the South: European Centre for Public Law in Legrena, Lavrio, Greece (built in the frame of Thermie-project MEDUCA in 1999/2000) 2 groundwater heat pumps (80 and 120 kW) with production and injection well, yield up to 25 m3/h Photo: CRES Photo: Google

Further successful (non-residential) applications in Germany convention centre factory logistics facility railway station shopping mall supermarket town hall …and many more

New headquarters of Leica AG, Wetzlar (inaugurated May 2014) Photo: UBeG

New headquarters of Leica AG, Wetzlar Located in a former military area, now converted into a business- and science-park Already other BHE systems in same area

New headquarters of Leica AG, Wetzlar Total of 80 BHE each 120 m deep in two fields Very complex energy system, including heat pump, CHP, peak boiler, absorption chiller, etc. FEFLOW- modeling to determine temperature distribution in the field and prove their is not interaction of the fields (figure: UBeG) Simplified schematic of the energy system

New headquarters of Leica AG, Wetzlar Drilling with 3 rigs simultaneously (February 2012) Finished BHE field before connecting (March 2012) Photos: UBeG

2009 2004 Reclamation of a former industrial site: Photo and graph: BonnVisio - Bonner Bogen Reclamation of a former industrial site: - 5-star-plus hotel “Kameha Grand” - Several blocks of offices - Location on banks of river Rhine - Preservation of some landmark elements from former buildings First, smaller GSHP project in 2004 Second, much larger stage in 2009

Groundwater heat pump system based on 6 wells Photos and graphs: UBeG GbR / BonnVisio - Bonner Bogen Groundwater heat pump system based on 6 wells

Final well diameter Ø 800 mm Photos and graphs: UBeG GbR / BonnVisio - Bonner Bogen Final well diameter Ø 800 mm Groundwater heat pump system based on 6 wells

Photos and graphs: UBeG GbR / BonnVisio - Bonner Bogen neighbour Large groundwater heat pump system require numerical simulation for design In the sample case, influence of varying groundwater level, and interaction with river Rhine and with neighbouring plants had to be checked neighbour 2009 2004 River Rhine

The groundwater system provides ca 1 MW of heat and cold as baseload Photos and graphs: UBeG GbR / BonnVisio - Bonner Bogen The groundwater system provides ca 1 MW of heat and cold as baseload well 8

Shallow Geothermal Cooling can save energy Shallow Geothermal Cooling can save energy ! Highest efficiency is with direct cooling: - Only possible in moderate climates, not too humid - Cooling-SPF in the order of 20-50 is possible Cooling using heat pump as chiller can be done everywhere - Can replace directly conventional air conditioning - Cooling-SPF much better than with chillers using air as heat sink

Some hints to reading from Europe: www.egec.org www.regeocities.eu www.rhc-platform.org

Thank you very much for your attention! Mit den folgenden Bildern können Sie die Zwischenfolien variieren – passend zur Veranstaltung.