1 Ground Source Heat Pumps Ground Source Heat Pumps in Scandinavia in Scandinavia - a success story a success story Göran Hellström Göran Hellström Lund University, Sweden Lund University, Sweden Geoenergy Ltd, UK Geoenergy Ltd, UK The National Energy Foundation, 12 The National Energy Foundation, 12 th th May 2005 May 2005 Ground Ground- Source Heat Pumps Source Heat Pumps Country Number of installations Country Number of installations n USA 900,000 USA 900,000 n Sweden 275,000 Sweden 275,000 n Norway Norway 13,000 13,000 n UK UK 3,000 3,000 n Rest of Europe 250,000 Rest of Europe 250,000 Ground Ground- Source Heat Pumps Source Heat Pumps 30,000 ground 30,000 ground-source heat source heat pumps with pumps with vertical vertical boreholes are installed boreholes are installed each year in Sweden each year in Sweden Sweden’s total demand for heating and cooling is ca 100 TWh Sweden’s total demand for heating and cooling is ca 100 TWh In 2000 about 15% of this energy was produced by ground In 2000 about 15% of this energy was produced by ground-source systems source systems In 2010 the ground In 2010 the ground-source contribution is expected to have doubled source contribution is expected to have doubled 10,000 ground 10,000 ground-source heat source heat pumps with pumps with horizontal horizontal loops are installed each loops are installed each year in Sweden year in Sweden Single or Block Residents Number of systems (5-100 kW) 275 000 Average load capacity 12 kW Full load hours 3 600 h Extraction of ground heat at COP 3,0 7 900 GWh Larger Systems Number of systems (100 –20 000 kW) 700 Average load capacity 1 000 kW Full load hours 4 500 h Extraction of ground heat at COP 3,0 2 100 GWh Total energy extracted 10 TWh/year Total energy produced 15 TWh/year Ground Ground- Source Heat Pumps Source Heat Pumps Natural Heat Extraction (2004) For Single Residents, 7 900 GWh Larger Distribution Systems, 2 100 GWh Corresponds to 10 % of total space heating demand CO 2 reduction with 2,3 Million tons or 3,5 % of the total emission Ground Ground- Source Heat Pumps Source Heat Pumps Ground-source heat pumps in Stockholm Swedish Geological Survey
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The National Energy Foundation, 12 Ground-Source Heat PumpsGround-Source Heat Pumps 30,000 ground-source heat pumps with vertical boreholes are installed each year in Sweden Sweden’s
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Ground Source Heat PumpsGround Source Heat Pumpsin Scandinavia in Scandinavia
-- a success storya success story
Göran HellströmGöran HellströmLund University, SwedenLund University, Sweden
Geoenergy Ltd, UKGeoenergy Ltd, UK
The National Energy Foundation, 12The National Energy Foundation, 12thth May 2005May 2005 GroundGround--Source Heat PumpsSource Heat PumpsCountry Number of installations Country Number of installations
nn USA 900,000USA 900,000
nn Sweden 275,000Sweden 275,000
nn NorwayNorway 13,00013,000
nn UKUK 3,0003,000
nn Rest of Europe 250,000Rest of Europe 250,000
GroundGround--Source Heat PumpsSource Heat Pumps
30,000 ground30,000 ground--source heat source heat pumps with pumps with verticalverticalboreholes are installed boreholes are installed each year in Swedeneach year in Sweden
Sweden’s total demand for heating and cooling is ca 100 TWhSweden’s total demand for heating and cooling is ca 100 TWh
In 2000 about 15% of this energy was produced by groundIn 2000 about 15% of this energy was produced by ground--source systemssource systems
In 2010 the groundIn 2010 the ground--source contribution is expected to have doubledsource contribution is expected to have doubled
10,000 ground10,000 ground--source heat source heat pumps with pumps with horizontalhorizontalloops are installed each loops are installed each year in Swedenyear in Sweden
Single or Block ResidentsØ Number of systems (5-100 kW) 275 000
Ø Average load capacity 12 kW
Ø Full load hours 3 600 h
Ø Extraction of ground heat at COP 3,0 7 900 GWh
Larger SystemsØ Number of systems (100 –20 000 kW) 700
Ø Average load capacity 1 000 kW
Ø Full load hours 4 500 h
Ø Extraction of ground heat at COP 3,0 2 100 GWh
Total energy extracted 10 TWh/year
Total energy produced 15 TWh/year
GroundGround--Source Heat PumpsSource Heat Pumps
Natural Heat Extraction (2004)
⌦ For Single Residents, 7 900 GWh
⌦ Larger Distribution Systems, 2 100 GWh
Corresponds to
⌦ 10 % of total space heating demand
⌦ CO2 reduction with 2,3 Million tons
⌦ or 3,5 % of the total emission
GroundGround--Source Heat PumpsSource Heat Pumps
Ground-source heat pumps in Stockholm
Swedish Geological Survey
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Ground source heat pumps in Stockholm
Swedish Geological Survey
Ground source heat pumps in Gothenburg
Swedish Geological Survey
GroundGround--Source Heat PumpsSource Heat Pumps⌦ 275 000 Installations⌦ 80 000 km Plastic Pipe Installed⌦ Annual Growth Rate > 30 %⌦ Drilling Industry Doubled in 10 years⌦ Side Industrial Growth Considerable
nl
ee
r
1986 1988 1990 1992 1994 1996 1998 2000 2002 2004
10,000
20,000
30,000
40,000
50,000
60,000
1985
Accumuleratfram till 1985
Prognosuntil 1985 2004
Inst
alla
tions
/yea
r
Borehole Heat ExchangerBorehole Heat Exchanger
Developed industrial production of borehole heat exchangerDeveloped industrial production of borehole heat exchanger
⌦ Groundwater Heat ⌦ Aquifer Thermal Energy Storage
(ATES) ⌦ High Temperature Underground
Storage under Development
Open Loop SystemsOpen Loop Systems TypicalTypical Swedish GSHP InstallationSwedish GSHP Installation
⌦ Ground Source Temp, 7 oC⌦ Borehole Length, 150 m⌦ Borehole Capacity, 7 kW⌦ Ground Loop Temp Design, -3/0 oC⌦ Distribution Temp, 50/40 oC⌦ Heat Production, 30 000 kWh/a⌦ System COP 3.3⌦ Energy savings, 21 000 kWh/a⌦ Heat pump technical life 15-20 years⌦ Borehole technical life 30-50 years⌦ Payback time, 7 years
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⌦⌦ Ground Source Heating (and Cooling) is well established Ground Source Heating (and Cooling) is well established
⌦⌦ Technologies are proven to be energy efficient, profitable and Technologies are proven to be energy efficient, profitable and environmentally beneficial by scientific evaluationsenvironmentally beneficial by scientific evaluations
⌦⌦ Main obstacles for further market deployment are:Main obstacles for further market deployment are:
üü Lack of recognition by authorities, politicians, etc.Lack of recognition by authorities, politicians, etc.
üü Lack of education, general knowledge and competent designersLack of education, general knowledge and competent designers
üü Resistance from the established energy industry, who represent Resistance from the established energy industry, who represent the “conventional systems”the “conventional systems”
nn Compact GHE design can be achievedCompact GHE design can be achievednn Verified in Swedish climateVerified in Swedish climatenn Cheaper than boreholesCheaper than boreholesnn No thermal influence on neighborsNo thermal influence on neighbors
nn Hybrid system Hybrid system –– horizontal loops horizontal loops combined with vertical boreholescombined with vertical boreholes
Temperatures in solar collectors and borehole heat storeTemperatures in solar collectors and borehole heat store
DärlingenDärlingen, Switzerland, Switzerland
Solar heat collection from road surfacesSolar heat collection from road surfaces
DärlingenDärlingen, Switzerland, Switzerland
Summer: heat from bridge deck stored in borehole heat storeSummer: heat from bridge deck stored in borehole heat store
Winter: heat from store keeps the road frost freeWinter: heat from store keeps the road frost free
Infra CityInfra CityUpplandsUpplands--VäsbyVäsby, Sweden, Sweden
Infra CityInfra CityUpplandsUpplands--VäsbyVäsby
Ø Offices 100.000 m2
Ø Winter: ground heat extraction and district heating
Ø Summer: cooling machine with ground and air
Ø 64 boreholes to 110 meters depth
Ø In operation: 1989-2001
Infra CityInfra CityUpplandsUpplands--VäsbyVäsby
Borehole configuration Borehole configuration –– spacing 4 mspacing 4 m
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Infra CityInfra CityUpplandsUpplands--VäsbyVäsby
Fluid temperatures and mean store temperature (measured)Fluid temperatures and mean store temperature (measured)
0
5
10
15
20
25
30
35
40
0 50 100 150 200 250 300 350
Days
Tem
pera
ture
(C)
Outlet temperature
Inlet temperature
Mean store temperature
Näsby Parks Slott, StockholmNäsby Parks Slott, Stockholm
Hybrid system Hybrid system -- Boreholes with summer recharge from lakeBoreholes with summer recharge from lake
Näsby Parks SlottNäsby Parks Slott
Heat load from buildings (18.000 mHeat load from buildings (18.000 m22) marked in yellow) marked in yellow
Boreholes
Water intake
Water outlet
Näsby parks slott Näsby parks slott GroundGround--coupled heat pump with recharge from the seacoupled heat pump with recharge from the sea
HP48 boreholes
Lake
48 boreholes x 180 m
Granite 3,9 W/m,K
Temperature 8,5 C
Heat pump 400 kW
Run hours 6000 h
Heat supply 2400 MWh
Cost of borehole storage
230,000 EUR Borehole storage without lake recharge:80 boreholes400,000 EUR
Lake water temperatureLake water temperature
0
5
10
15
20
25
1 2 3 4 5 6 7 8 9 10 11 12Month
Wat
er te
mpe
ratu
re (C
)
Normal water temperature
High water temperature
Näsby parks slott Näsby parks slott GroundGround--coupled heat pump with recharge from the seacoupled heat pump with recharge from the sea
Energy flows and temperatures 040927Energy flows and temperatures 040927
HP48 boreholes
+13,2+9,8
+9,7
+5,8
Lake
+11,2
17 l/s
11 l/s +38,0
+41,8
263 kW180 kW
250 kW
70 kW
6 kW
2,2 kW
83 kW
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Näsby parks slott Näsby parks slott GroundGround--coupled heat pump with recharge from the seacoupled heat pump with recharge from the sea
Energy flows and temperatures 041117Energy flows and temperatures 041117
HP48 boreholes
+4,3+3,4
+5,5
+2,5
Lake
+3,6
17 l/s
15 l/s +38,7
+42,8
284 kW177 kW
62 kW
115 kW
10 kW
2,2 kW
102 kW
ProfitabilityProfitabilityEstimated based on first seven months of operation Estimated based on first seven months of operation (june(june--december 2004)december 2004)
Alternative 1. Oil Alternative 1. Oil Alternative 2. GroundAlternative 2. Ground--source heat pump and oil (peak)source heat pump and oil (peak)
nn New facilities for New facilities for manufacturing of manufacturing of medicinemedicine
nn Building consists of four Building consists of four storeys incl. basementstoreys incl. basement
nn Total areaTotal area ca 7020 mca 7020 m22
nn Energy service rooms Energy service rooms prepared for future prepared for future storage space of ca storage space of ca 2000 m2000 m22
Design load & criteria Design load & criteria
Annual energy loadAnnual energy loadCapacityCapacity
330 kW330 kW
90 kW90 kW
160 kW160 kW
410 kW410 kW
305 MWh305 MWhCool load Cool load summersummer
190 MWh190 MWhCool load Cool load winterwinter
50 MWh50 MWhHeat load Heat load summersummer
925 MWh925 MWhHeat load Heat load winterwinter
Design loadsDesign loads
Criteria for system design:l Boreholes designed for max entering fluid temp +14 °Cl All air cooling coils designed for 14-17 °Cl All air heating coils designed for 50-35 °C
Geological conditionsGeological conditions
nn 00--25 meter soft clay25 meter soft clay
nn 2525--30 meter silt / sand30 meter silt / sand
nn 3030--200 meter granite200 meter granite
Ground water level ca 4 meter below ground surface
Borehole configurationBorehole configuration
Boreholes are drilled from a trench along the property border and gradedunder the building to achieve suitable borehole spacing in the ground
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BoreholesBoreholes
nn 38 boreholes for heat pump and 38 boreholes for heat pump and direct coolingdirect cooling
nn 168 mm steel casing to a depth 168 mm steel casing to a depth of ca 30 mof ca 30 m
nn 140 mm borehole to a depth of 140 mm borehole to a depth of 200 m200 m
nn 2 x 40 mm PEM U2 x 40 mm PEM U--pipe in each pipe in each boreholeborehole
nn Boreholes are filled with Boreholes are filled with groundwatergroundwater
168 mm ODEX drilling for casing.Removal of water and cuttings to container
BoreholesBoreholes
Fitting of 168 mm cap on the casing fora single U-pipe with PEM 40 mm pipes
Installation equipment for U-pipe PEM 40 mmU-pipe filled with 29% ethanol/water solution
Header pipesHeader pipes
Testing horizontal pipes from boreholesbefore connecting to manifold
Horizontal pipes (PEM 50 mm) before being covered with thermal insulation sheets
Electric welding to join borehole pipes (PEM 40 mm)with horizontal pipes (PEM 50 mm) connecting boreholeswith manifold in energy service room
ManifoldsManifolds
Manifolds of stainless steel with throttle valves for each header pipe (borehole)
Energy service roomEnergy service room
nn 6 heat pumps with 41 kW capacity6 heat pumps with 41 kW capacity
nn Three of the heat pumps fitted Three of the heat pumps fitted with desuperheaters forwith desuperheaters forheating of tap waterheating of tap water
nn Refrigerant R407CRefrigerant R407C
nn Electric heater 255 kWElectric heater 255 kW
Heat pumps (IVT Greenline F40H) in the service room
BTES heating and free cooling combined with district heatingBTES heating and free cooling combined with district heatingOffice space 4.900 mOffice space 4.900 m22
Straight payStraight pay--backback time:time: 4,1 years4,1 years
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BTES design toolBTES design toolEED EED –– Earth Energy DesignerEarth Energy Designer
nn easy and fast to use (GUI)easy and fast to use (GUI)
nn ground propertiesground properties
nn borehole heat exchanger (type, depth, material, filling materialborehole heat exchanger (type, depth, material, filling material ))
nn 307 predefined borehole configurations307 predefined borehole configurations
nn heat carrier fluidheat carrier fluid
The model provides databases for the input data and also reThe model provides databases for the input data and also re lies on a database lies on a database
of preof pre--calculated response functionscalculated response functions
Results:Results: fluid temperature variation and required borehole lengthfluid temperature variation and required borehole length
Base loadPeak cool loadPeak heat load
Year 25JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Flui
d te
mpe
ratu
re [º
C]
7
6
5
4
3
2
1
0
-1
BTES simulation modelBTES simulation model
SBM SBM –– Superposition Borehole ModelSuperposition Borehole Model
nn homogeneous ground propertieshomogeneous ground properties
Open loop system in hard rockOpen loop system in hard rock CoolingCooling in industrial processesin industrial processes
BTES ApplicationsBTES Applications
nn Based on developed techniques and parts Based on developed techniques and parts nn Low operational costsLow operational costsnn Reasonable payReasonable pay--back timesback timesnn Seasonal energy storageSeasonal energy storagenn Potential for further developmentPotential for further development
nn Heating Heating andand coolingcoolingnn Large fraction renewable energy (75Large fraction renewable energy (75--80 %)80 %)
nn HeatingHeatingnn Recharging with renewable (water, air, solar)Recharging with renewable (water, air, solar)
A sustainable and cost effective choice!A sustainable and cost effective choice!
Large hybrid groundLarge hybrid ground--source systemssource systems