Melting rocks to save energy

It all makes sense when you visit the Rockwool Insulation campus in Denmark.

Wed, Oct 07 2009 at 6:57 PM EST

Photo: Karl Burkart

When you think cleantech in Denmark the first thing that comes to mind is wind power… for good reason. 5,200 wind turbines dot the Danish landscape and provide a full 20% of the nation’s energy demand. Moreover, the Danes have manufactured half of the 40,000 megawatts of installed wind power worldwide.

But the drive for renewable energy is matched in Denmark by an equal drive for energy efficiency, which they call “the sixth fuel.”

Today on our whirlWIND tour of Denmark we visited Rockwool Insulation, a leading manufacturer of just such a “sixth fuel” -- ultra-efficient insulation. Their research team is headquartered in a gloriously uber-modern campus in Hedehusene where the process of transforming molten rock into sound-proof, fire-resistant super-performing insulation has been perfected.

Rockwool is a key player in the Danish quest for a 20% reduction in total energy consumption by 2020, and they hope to bring their products soon to the United States. Or I should say back to the USA, as the technology (like both solar and wind) was originally invented in the States.

Denmark was hit very hard by the 1973 oil embargo and (unlike the U.S.) it learned its lesson. The government funded massive R & D efforts to ensure that Denmark would never be so reliant upon foreign fuels. And Rockwool was one of the companies that expanded rapidly during this period, providing proof for the oft-stated truism, “The cheapest form of energy is the energy you don’t use.”

Back in the 30’s a Danish entrepreneur purchased a license from an American company to manufacture Rockwool in Europe. When the U.S. construction industry turned to cheaper alternatives like asbestos and fiberglass, Rockwool (called Roxul in North America) became the world leader in this technology.

You wouldn’t think that melting rock at 1000 degree temperatures would be very good for the environment, but according to Thomas Nordli who led us around the campus, the carbon hit is paid pack many times over in terms of reclaimed energy.

Over a typical 50 year life span of the product, 100 times the energy consumed in the manufacturing process is saved by reduced heating and cooling demand:

In a case study recently performed for a typical home in Denmark (much smaller than an American home mind you) new insulation in conjunction with other measures including insulating pipes and windows resulted in a net savings of 57%. CO2 was reduced by 8 tonnes and in just one year the occupant saved $2500 (which factors in the extraordinarily high energy taxes in Denmark).

The material stock for Rockwool is basalt, which is melted, spun into fiber, that is then compressed into various configurations – exterior board, batt insulation, rigid insulation and pipe wraps.

While not nearly as sexy as their lithe windmill cousins, Nordli says that insulation products are the fastest way to reduce dependence on foreign fuels. In the EU 41% of all energy consumed is for the building sector, and of that nearly 2/3 is used for heating and air conditioning.

Theoretically that energy load (what amounts to 27% of all energy consumed) could be cut in half, or more.

This would greatly benefit the economy as a whole. According to a recent study by Ecofys, energy efficiency improvements in Europe could save 270 billion Euro, 460 million tonnes of CO2 and create 500,000 jobs.

In the U.S. thse same actions would result in 1.1 million new jobs and would increase personal income by $28.5 billion.

MNN homepage photo: claylib/iStockphoto