where space for drilling and laying traditional geothermal
heat exchangers is limited.
Another advantage is their cost-efficiency. Energy piles
usually deliver heating to the building at a co-efficient of
performance (COP) of between 3.2 and five. Also, energy piles
are even more effective at cooling than heating. They provide
a natural cooling effect during the summer, when the cool
fluid from the energy piles (8°C to 10°C) is circulated
throughout the building. The fluid draws out the excess heat
in the building, lowering the temperature and providing
efficient comfort cooling at an energy efficiency of 20 to 30
kilowatt hours of cooling per one kilowatt hour of electricity
provided. This excess heat is transferred to the ground below
the building, creating a heat storage by providing energy to
the ground, which can be extracted when heat is needed.
A further benefit to using energy piles is their environmental
sustainability. “Since the energy provided for heating and
cooling comes from the ground, all it takes to operate the
system is the added electricity, which – at least in Denmark
– often comes from wind energy. Thus, the energy piles
provide 100 per cent renewable energy on days where
electricity is provided through wind, sun or hydro technology,”
said Henriksen.
In collaboration with Centrum Pæle A/S, researcher Maria
Alberdi-Pagola studied the design and performance of energy
piles. Her subsequent 2018 thesis simulated the long-term
effects and feasibility of the technology.
“Alberdi-Pagola developed a tool that can accurately
determine how many energy piles are needed to satisfy the
PRODUCT SPOTLIGHT
energy demand and also if the ground beneath is able to
supply the necessary energy. The tool also suggests a foundation
plan that outlines how to place the energy piles to avoid them
cannibalizing on each other’s energy,” said Henriksen.
Energy piles in Canada: Realistic?
The way Henriksen sees it, energy piles can be used in most
parts of the world.
“You need to start working with them from the earliest
stages of a project as it does take quite a bit of planning
between the heat pump manufacturer, plumbing installer
and the producer of the piles themselves to make the right
dimensioning of the system,” he said.
He says the perfect stage to start thinking about energy
piles is when the geographical location of the building is
decided, the building drawings are available and the energy
demand profile for the building is known.
“These factors allow us to use our dimensioning tool
to determine whether or not energy piles will be feasible
for the given project. This investigation uncovers whether
they can provide the necessary energy stated in the energy
demand profile for the building without depleting the
ground of heat, resulting in permafrost which renders the
system useless.”
Centrum Pæle A/S was founded in Vejle, Denmark in 1965,
and has expanded to include five factories across Europe.
Together, they produce four million metres of precast concrete
piles every year. For more information on energy piles, check
out a two-minute video at youtu.be/7ZsnIxbi1z8.
AARSLEFF GROUND ENGINEERING
Per Aarsleff A/S is one of Northern Europe’s leading civil engineering contractors.
With ground engineering subsidiaries based in Denmark, Germany, Sweden, Poland,
Norway and the UK, the Group are well placed to deliver their specialist expertise.
The Aarsleff Group carries out a broad range of
ground engineering works. In addition to driven
and drilled pile foundations, we design and install
construction pits with retaining walls such as
sheet pile walls and combi walls, secant pile walls,
diaphragm walls as well as driven and drilled
king post walls. Our expertise also comprises
anchoring and injection work, geotechnical
investigations and groundwater lowering systems.
Centrum Pile is Europe’s leading reinforced precast concrete pile
manufacturer. Centrum’s state-of-the-art facilities utilise the most
advanced robot technology and on-site concrete batching to ensure
strong, durable and robust reinforced precast concrete piles.
Operating across Denmark, Germany, Sweden, Poland, Norway and the UK.
Email: jessicabanham@aarsleff.co.uk Call: 01636 611140 Website: www.aarsleff.co.uk
PILING CANADA 27
/www.aarsleff.co.uk
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