Energy piles
Heating and

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- eine geothermisch aktivierte Tiefgründung

Structures have to be built with depth foundations if difficult foundation conditions or very high loads occur.
Where pile foundations are needed, there is the opportunity of an additional geothermic use of the ground by using energy piles (geothermically activated in-situ concrete or ready-mix concrete piles, hollow piles, press piles).
First science-assisted, practical implementations of energy pile systems took place in the 1970s in Switzerland.
Meanwhile, this innovative energy technology has been successfully implemented in Germany (a.o. Katzenbach 1997, Brandt et al. 2003).

The thermal use of (near-surface) ground is defined, among others, in the VDI standard 4640 (sheet 2). Energy piles are categorized as "special heat source (reduction) plants" there.

Energy piles have two functions:
According to their main function, they transmit loads into the foundation. In addition, they can be used as geothermal heat transmitters.
Uses of the foundation piles as energy piles must not impair their load bearing capacity. Any reduction of the pile’s load capacity (occurrence of frost, diameter reduction by heat exchange pipes) has to be imperatively eliminated (temperature limitation, static tests).


Energy pile plants are mostly base load plants. Peak powers have to be covered by other systems, if applicable. Detached houses with depth foundation can be supplied increasingly monovalent by energy piles (improved insulation).

Assumptions regarding installation and operation of energy pile plants

 The statics of the structure are determined by the arrangement and number of the foundation piles. In many cases, an arrangement of the foundation files according to energy aspects is economically inefficient (exception: e.g. inexpensive pre-fabricated foundation piles, sometimes even used as „lost piles“)

 An energy pile plant should preferably be used as alternating storage system (heating or cooling operation, depending on the season). Thus, an optimum specific extract performance [W/m] either for heat or coldness production can be reached. The temperature regime of the energy pile plant can be designed in a sustainably stabile way. A well-adjusted heat balance over many years minimizes the mutual thermal effect of neighbouring energy piles.

Energiepfahlanlage Rostock
Energy pile plant

Driven energy pile

H.S.W. Ingenieurbüro
Gesellschaft für
Energie und Umwelt mbH

Gerhart-Hauptmann-Str. 19
18055 Rostock (Germany)

tel.: 0049 (0)3 81/ 3 70 15
fax: 0049 (0)3 81/ 3 12 24
mobil: 0151/ 12 74 55 02
email: hsw.ingbuero@t-online.de
web: www.hsw-rostock.de