renewable energy geothermal energy in...

RENEWABLE ENERGY

GEOTHERMAL ENERGY IN COMBINATION WITH HEAT PUMP

AND EXAMPLES OF PRACTICE

© REHAU

BASIS

WHAT ARE THE ADVANTAGES OF GEOTHERMAL ENERGY?

- Domestic, ecologic source of energy

- Cosistent – independet of weather conditions, seasons and times of day

- Inexhaustible and sustainble energy source

(according to human perion)

- Using the all year round obtained geothermal energy for heating the building in winter and cooling

in summer

- Energy savings for heating up to 75% and for cooling up to 85%

- To a large extent independent of increasing the price of fossil fuels

- A significant reduction in CO2 emissions

- Facilities for the use of geothermal energy are almost invesible below the surface

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Deep geothermal (from within the ground) (> 400m)

- Hydrothermal systems (using water stores)

- Petrothermal systems (artificially pumping water deep underground)

- Deep geothermal probes (using a closed loop system)

Ground-source (from the sun) (< 400m)

- Ground-source collectors (sub-surface, at a depth of 1.5m)

- Ground-source probes (using boreholes at depths of ca.100m)

- Ground-source spiral probes (spiral probes buried up to 5m deep)

- Ground-source energy piles (using the building foundations)

- Ground water bore holes (open loop systems using ground water)

- Ground-air heat exchanger (using mechanical ventilation)

INTRODUCTION WHAT TYPES OF GEOTHERMAL ENERGY ARE THERE?

300m

10m

0 m

summer winter

Rain 13 W/m² Solar radiation

up to 600 W/m²

0,06 W/m² Geothermal heat flow

20 0 10

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SEASONAL VARIATIONS OF GROUND TEMPERATURE

INTRODUCTION

February

May

August

November

Temperature C

Depth

(m)

Increase of ca. 3K

per 100m depth

BASIS

USING GEOTHEMRAL ENERGY FOR HEATING WITH HEAT PUMP

Getting of the geothemral energy

Increasing the temperature

level with heat pump

Underfloor heating

3 C 40 C

32 C 0 C

BASIS

USING GEOTHERMAL ENERGY FOR COOLING WITH HEAT PUMP

Giving the heat to the Earth for faster

regeneration and accumulation

Decreasing the temperature level

with heat pump

Taking the heat from the object

with underfloor heating

15 C 16 C

19 C 22 C

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Best solution: Combine heating in the winter and cooling in the summer

10 C

0 C

Jan Jan

Advantages: + Faster regeneration of ground temperature

+ Rise in efficiency and heat quality

+ Utilization of free cooling

Jan

10 C

0 C Jan Dec

10 C Jan Dec

Ground temperature rises during the cooling period,

requiring subsequent regeneration

Ground temperature sinks during the heating period,

requiring subsequent regeneration

WHY GROUND REGENERATION IMPROVES THE PERFORMANCE

INTRODUCTION

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INTRODUCTION WHAT ARE THE ADVANTAGES OF GROUND-SOURCE ENERGY?

- Renewable and sustainable energy source

- Year round usage – independent from climate & season

- Reduced carbon emissions for both heating and cooling

- Can provide space heating, hot water and cooling

- No fuel deliveries required

- Low maintenance costs

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INTRODUCTION HOW DOES A GROUND SOURCE HEAT PUMP WORK?

Ground loop (vertical / horizontal)

Space heating circuit

(ideally underfloor heating)

0 C

4 C

30 C

35 C

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COEFFICIENT OF PERFORMANCE OF HEAT PUMP

EFFECT OF FLOW TEMPERATURE

0

1

2

3

4

5

6

7

-5 0 5 10 15

Heating Water temp in °C

En

erg

y u

se

ε (

CO

P) T = 35°C

T = 45°C

T = 55°CC.O.P

Return temperature of ground-source circuit C

Flow temperature

of heating circuit

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Domestic applications:

- Vertical probes

- Spiral / helix probes

- Coaxial probes for radial drilling

- Horizontal collectors

- Energy piles

Commercial applications:

- Vertical probes

- Energy piles

- HPR probes (up to 800m)

FOR EVERY DEMAND AN INDIVIDUAL GROUND-SOURCE SOLUTION

THE RIGHT SYSTEM CHOICE

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FOR EVERY DEMAND AN INDIVIDUAL GROUND-SOURCE SOLUTION

THE RIGHT SYSTEM CHOICE

Probe Collector Helix® Coaxial probes Energy piles

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- Higher resistance to notches and grooves - no reduction in lifespan when notches

travel 20% into the wall

- No susceptibility to point loads

- No thermal changes in properties at long periods of up to 95 C

- Higher chemical resistance over PE 100

- Lower pressure losses (PE-Xa pipe roughness 0.007mm, PE = 0.04mm)

- Improved bending radius

- Everloc compression sleeve fitting

CHOOSING THE RIGHT MATERIAL ADVANTAGES OF PE-Xa OVER PE 100

PE 100

PE-Xa

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Due to the high temperature resistance of PE-Xa (-40 C to 95 C), PE-Xa can be combined with solar thermal

systems.

Excess solar thermal energy in the summer can be stored in the ground to increase the COP.

PROBES COMBINATION WITH SOLAR THERMAL ENERGY

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- Double-U probes provide built-in reliability – ‘bury and

forget’

- 2 flow and 2 return circuits

- If any probe failure occurs, still having working circuit

- Additional thermal outputs of around 10-15% per probe

PROBES DOUBLE-U PROBES

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HPR PROBES PILOT SITE PHOTOS

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COLLECTORS FOR PROJECTS WITH LARGE SURFACE AREA AVAILABLE

PE 100

collectors

PE-Xa

collectors

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COLLECTORS HORIZONTAL COLLECTORS – PIPE MATERIAL OPTIONS

PE-Xa collectors:

- High resistance to notches &

grooves

- Sand bed is not required

- Laying in small areas due to tight

bending radius

PE 100 collectors:

- Manufactured to DIN 8074 /8075

- Sand bed is required

PE-RC collectors:

- Manufactured to PAS 107

- Sand bed is not required

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COLLECTORS INSTALLATION OF COLLECTORS

With PE 100, a sand bed is

required

PE-Xa collectors PE 100

collectors

PE-Xa

collectors

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COLLECTORS PIPE SPACING

• Slinky systems popular due to low installation costs

• Pipes laid in coils in trenches – 0cm pipe spacing

• Can cause problems by extracting too much energy

affecting long-term GSHP performance

VDI 4640 (part 2, p13) states:

“When determining the installation distance (usually

between 0.3m and 0.8m) it must be considered that the ice

radii forming around the extraction pipes must not merge”

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HELIX PE-Xa COMPACT FORM OF ENERGY EXTRACTION

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- 4.2m deep borehole – simple to drill

- For new builds and refurbishments

- Low storage, transport and installation costs

- Expands from 1.1m to 3m

- High-quality PE-Xa material for safe installation and

long-term reliability

HELIX PE-Xa COMPACT FORM OF ENERGY EXTRACTION

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Auger drilling: Further 3m deep Create trench 1.2m deep

HELIX PE-Xa INSTALLATION PHOTOS

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Backfill = excavated material

(or sand / water if poor soil)

HELIX PE-Xa INSTALLATION PHOTOS

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ENERGY PILES EXPLOITING THE BUILDING‘S FOUNDATIONS

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PE-Xa is ideal due to its small bending radius,

allowing for a simple installation.

ENERGY PILES

Concrete piles are sometimes required for stability due

to poor load-bearing soil.

Ground-source pipework can be integrated to exploit

ground-source energy.

EXPLOITING THE BUILDING‘S FOUNDATIONS

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Navarino Holiday Resort, Greece

Ground-source heating and cooling using

130km collect PE-Xa and 130 industrial

manifolds.

CASE STUDIES

GROUND-SOURCE SYSTEMS

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Kinsale Lifeboat Station, Ireland

Ground-source heating using 1200m of PE-Xa pipe integrated into

structural concrete caissons, which support the building. Uses tidal

flow to extract ground-source energy.

CASE STUDIES


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Suffolk One College, Ipswich

Used ICAX interseasonal heat transfer

system. 14,000m of 25mm PE-Xa pipe used

for solar capture and 18 x 100m PE-Xa probes

for heat storage

CASE STUDIES


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Tesco store – Greenfield, Oldham

CASE STUDIES


Interseasonal heat transfer with 9 x 150m probes for heating and cooling 25,000 ft² store. Recovers heat

from store in summer and stores it in ground for extraction in winter.

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Wellington Civic Centre

Used ICAX interseasonal heat transfer system.

4,000m of 40mm PE-Xa pipe used for solar capture

and 20 x 110m PE-Xa probes for heat storage

CASE STUDIES


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Solar Storage Crailsheim (DE)

In one of the largest geothermal heat reserves in Germany,

the excess heat from 10,000m2 of solar collectors in the

summer is saved for use in the winter with help of 80 PE-

Xa probes.

CASE STUDIES


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Berkentin Bridge, Germany

Winter operation:

• Keeps the road snow and ice free - less requirement for gritting

Summer operation:

• Thermal regeneration of the ground

• Cools the asphalt surface -increasing lifespan of the road

6,300m of 25mm stabil PE-Xa pipe (with integrated aluminium

layer) was used. Able to be laid directly in asphalt at temperatures

of up to 240 C

GROUND-SOURCE SYSTEMS CASE STUDY - BRIDGE HEATING

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Platform Heating Bad Lauterberg, Germany

Clearing of snow and ice on the platforms with ground-source

energy using collect PE-Xa and RAUGEO probes PE 100.

CASE STUDIES


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The Lakes - Yoo 6, Gloucestershire

- PE Collect laid in lakes for optimum performance

- 700m in total

- 160 luxury houses over next 3 years

GROUND-SOURCE SYSTEMS CASE STUDIES

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Grand Designs House, Kent

Ground-source heating using PE-Xa energy piles.

Used with Underfloor heating

CASE STUDIES


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Commercial building „Energotehnika – Juzna Backa”

in Novi Sad

Heating and cooling with geothermal

60 PE-Xa-probes 125m,

4.000 m collect PE-Xa connecting pipes to

manifold,

1.200 m INSULPEX connecting pipes to heat pump.

Geothermal probes are in green area and under

parking place.

REFERENCE OBJECTS IN SERBIA

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First low-energy housing building in Serbia

AMADEO, Beodom, Belgrade

Heating and cooling with geothermal energy

2x5 PE-Xa-probes 100m, 500 m collect PE-Xa

connecting pipes to manifold

Geothermal probes are under the building and in

green area.

DHW with solar system.


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Low-energy housing building AMADEO 2, Beodom,

Belgrade

Heating and cooling with geothermal energy –

5 RAUGEO PE-Xa-probes 100m, 250 m RAUGEO

collect PE-Xa connecting pipes to manifold

HEAT PUMP Geo 30B

RAUTHERM S panel heating and cooling


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Low energy housing building in Stjepana Ljubise

Street in Belgrade.

Heating and cooling with geothermal energy –

4 RAUGEO PE-Xa-probes 125m, probes are under

the bulding.


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Commercial building in Novi Sad 3 PE-Xa 125m probes

60 m collect connecting pipes to manifold

HEAT PUMP GEO 37 BC

3500m panel heating and cooling

26 m pre-insulated pipes INSULPEX Duo 63+63/180mm


THANK YOU FOR YOUR ATTENTION

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