Bellenberg results prove energy-positive buildings possible

Measurements of the energy performance at Hydro’s aluminium building systems test center in Bellenberg, Germany, show that the building is generating 80 percent more electricity over the course of a year than it needs for its own consumption.

May 26, 2011

“We have had a dream about showing the market that energy-positive buildings are possible. We therefore built the test center in Bellenberg to try our own technologies in interaction with complementary solutions. In a world with many good intentions, we are proud to demonstrate that it actually is possible to build energy-positive buildings,” says Lars Hauk Ringvold, president of Hydro Building Systems.

The measurements show that the building produces enough energy to be self-sufficient, also when indoor testing activities are taken into account, while also delivering energy to the German electricity grid.

The most important explanation is an efficient façade that is designed to help reduce energy consumption to as little as 23 kilowatt-hours per square meter annually.

“A super-efficient façade is the most important contributor in the realization of an energy-positive building. To get from minus to the plus side, additional elements such as heat pumps and solar energy also have to be an integrated part of the solution,” says Ringvold.

Potential for more

Hydro uses a heat pump and solar cells to produce the necessary energy at the Bellenberg site. Still, Ringvold sees a significant potential for increasing the energy surplus.

“The first year is usually demanding in terms of starting up. Our experience is that we could have operated the building smarter, especially by using daylight more optimally, relative to lamplight. Optimizing the use of radiator heat in the cold period of the year will also contribute positively,” he says.


Business opportunities“In addition, it is necessary to spend some time to become familiar with the system and how it works. We are therefore very satisfied that the building, already in the first year, produced 80 percent more power than it has needed for its own use, and we assume the energy performance will be significantly better in the coming years,” says Ringvold.

Hydro has measured the energy performance at the test center in Bellenberg since April 2010. In fact, the building’s energy production and consumption figures are available every day on the internet (see link in the right-hand column).

Hydro is one of the leading suppliers of energy-efficient façade solutions in Europe and overseas, with its building systems brands Wicona, Technal and Domal.

“We see that the demand for façade solutions for zero-energy buildings and energy-positive buildings will increase significantly in the coming years as a result of tougher building regulations and the wish for a green future. This will open up many business opportunities for Hydro,” says Ringvold.

Also in the "cold" Norway

In Norway, Hydro recently entered into an alliance known as Powerhouse, with Entra Eiendom, Skanska, Snøhetta and Zero. The group is working to build the first energy-positive building in the country – and to show that energy-positive buildings are also possible in such northern climates.

The goal is that a successful showcase building will result in not just one such building, but many energy-positive buildings. Powerhouse is aiming to present its first building project in the summer of 2011.


Updated: October 11, 2016