In the business district of Lutakko in the Finnish city of Jyväskylä stands a fairly non-descript modern office building. Just a year old, the new development is, in fact, pioneering the use of ground source geothermal energy in a way that relies on the very fabric of the building.

This structure, Innova 2, rests on steel pilings that are driven into the ground, but these pilings contain heat transfer equipment too. There was a structural requirement for pilings given the yielding nature of the ground and use of the energy piles effectively eliminated geothermal pipe drilling costs. With 10,000 m² of floor space, when completed and taken into use in April 2012, Innova2 was the first project in Finland to have a system that includes ground source heat harvested with energy piles.

Some 5 km of pilings were delivered by Finnish steel company Ruukki during 2011 and 2012 to be used in 38 piling points, supporting a 270 tonne steel frame for the building. Lead contractor was NCC Construction Ltd using an architectural design from Arkjaatiset Oy.

The energy pile system was jointly developed by Ruukki and Uponor Corporation following energy pile simulation from Granlund Oy. The building also uses Are Sensus panels that heat and cool the premises from the ceiling, negating the need for conventional radiators.

Reduced energy consumption

Taking around 18 months to complete, the building was conceived as part of an environmental strategy by owner Technopolis to utilise more renewable energy and, according to initial estimates, has reduced energy consumption significantly, supplying around half of the energy needed for heating and some 40% of cooling demand. The preliminary results of operation support the estimations, and only some small adjustments will be made to ensure the system runs optimally.

With an estimated 10-year return on investment the energy piles will pay their costs back many times during the long lifetime of the building. Even so, of the roughly EUR20 million needed to construct the building the geothermal system accounted for a significant proportion, around EUR130,000.

Virve Valonen, environmental and sustainability manager, explains of the preliminary results: “We can see how close it will be to the estimates. We have big expectations and have already decided to use geothermal energy in planned extension of Innopoli campus in Otaniemi in Espoo.”

While the Innopoli extension is still in the planning phase, construction teams have already drilled the wells into the bedrock. “It's not exactly the same system as Innova 2, but it is quite similar,” Valonen explained.

Government support

To improve its energy efficiency in general, and to support its investments, Technopolis has signed up to a government-backed energy efficiency agreement for premises and gets state support for energy efficiency measures to the tune of 25% of the investment cost. The Finnish energy efficiency agreement was completed, with a supplemental agreement for buildings, in 2011, having been developed by Rakli, Finland's Environmental Administration and Ministry of Employment and the Economy alongside real estate organisations.

All parties to the pact publish their estates’ energy consumption and efficiency targets during the term of the deal, agreeing to reach a 6% reduction by the end of 2016. Technopolis joined the agreement at the beginning of 2011.

Due to Technopolis’ decision to increase the share of green electricity it uses from 45% to 100% at the beginning of 2012, the 1,300 companies in its premises in Finland are now using electricity produced with renewable energy sources. Green electricity is procured for all Technopolis campuses from Oulu Electricity Sales, Kuopio Energy and Vantaa Energy. Together with its green energy purchasing plans the geothermal project at Innova 2 has seen the building's carbon dioxide emissions fall by half.

LEED

With around a 160 building portfolio, the real estate company has also invested considerably in developing the environmental performance of its properties based on the LEED rating system. It has a total of 15 projects registered under LEED Core & Shell 2009 or Existing Buildings O&M 2009, located in Helsinki, Vantaa, Espoo, Oulu, Jyväskylä, Tampere, Kuopio, Tallinn and St. Petersburg. Nine of the LEED registered projects are new construction projects. Innova 2 achieved a LEED Core & Shell Platinum rating.

Technopolis also requires its cleaning, property maintenance and restaurant partners to have environmental programmes and to use environmentally friendly products where possible.

Although both Innova 2 and the Innopoli extension are new buildings, the company has looked at retrofitting geothermal energy in its existing buildings.

“We have considered also these renewable energy solutions, but only when the building is a little older and the technical systems are coming to the end of their life and we really need to renew everything in the building,” Valonen explained.

“We don't have so many of [those types] of buildings but we might have one prospective that is also on the Innopoli campus, and we are considering the case. However, we have not made any decisions.”

Long-term investment

Highlighting the long-term nature of property investment, Valonen notes the good return, even though payback time is around a decade.

“If we want to keep good buildings for a long time and be a committed investor then this is a good solution,” she stated.

Valonen also points out that the building's users also benefit from the geothermal system.

“Because we have planned and designed and built the systems so that it will stay energy efficient for a long time we will have more managed maintenance costs. They won't go up as easily as in other types of buildings.”

Considering the wider application of energy piles, Valonen believes the technology can be used for any type of building, though there must be sufficient heating and cooling loads to consume the full energy potential – making it suited to higher consumption types of premises such as data centres.

She also argues that the technology is a good addition to the urban environment, giving freedom from local energy provider decisions on energy sources, their CO₂ factors and pricing.

“I think energy piles are a brilliant new technology,” she declared. ♦

David Appleyard is a freelance journalist with extensive experience covering the energy, technology and finance sectors. He was formerly chief editor of Renewable Energy World magazine and Hydro Review Worldwide.

This article was published in the January/February 2014 issue of Renewable Energy Focus magazine.

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