Civil Engineering Reference
In-Depth Information
Table 2 Comparison of storage concepts (Novo et al.
2010
)
Storage concept
Hot water
Gravel water
Duct
Aquifer
Storage medium
Water
Gravel water
Ground material (soil/rock)
Ground material (sand/water-gravel)
Heat capacity
(kWh/m3)
60-80
30-50
15-30
30-40
Storage volume for 1 m
3
1m
3
1.3-2 m
3
3-5 m
3
2-3 m
3
Water equivalent
Geological
requirements
Stable ground conditions
Preferably no groundwater
5-15 m deep
Stable ground
conditions
Preferably no
groundwater
5-15 m
Drillable ground
Groundwater favourable
High heat capacity
High thermal conductivity
Low hydraulic conductivity
(k f \ 1 9 10
-10
m/s)
Natural groundwater flow \ 1 m/a
30-100 m deep
Natural aquifer layer with high hydraulic
conductivity (k f [ 1 9 10
-5
m/s)
Confining layers on top and below
No or low natural groundwater flow
Suitable water chemistry at high
temperatures
Aquifer thickness 20-50 m deep
