A future for skiing in a warmer world

Chances are if you know anything about Norway, you know it's a place where skiing was born.

Norse mythology describes gods and goddesses hunting on skis, and 4000-year-old petroglyphs from northern Norway include some of the earliest known drawings of people on skis. One of the most recognizable Norwegian paintings worldwide depicts two skiers in 1206 fleeing to safety with the country's two-year-old prince, Håkon Håkonsson.

Over the centuries, skiing in Norway has evolved from a practical mode of winter transport to a sport that is deeply ingrained in Norwegian culture. Norwegians themselves like to say they enter the world uniquely prepared for their northern home -- because they are "born with skis on their feet."

But warmer weather due to climate change has made for less-than-stellar ski conditions in Norway and across Europe. Advances in snowmaking, where water is "seeded" with a protein from a bacterium that allows snow to be made at temperatures right around freezing, simply aren't enough to keep up with the changing climate.

In response, a team of Norwegian researchers has been awarded a NOK 2.3 million grant from the Norwegian Ministry of Culture to develop a new approach to snowmaking -- one that would allow snow to be made in an energy-efficient way, even at warmer temperatures. The project has been named, appropriately enough, "Snow for the Future."

Putting heat pumps to work

Traditional snowmaking makes up for a lack of snow by spraying water into cold air, and letting physics do the rest. But if temperatures are above freezing, this simply won't work, for obvious reasons.

Researchers at SINTEF, Scandinavia's largest independent research institute, and the Norwegian University of Science and Technology (NTNU) have worked extensively with a type of technology called a heat pump. They think that heat pumps could be key to producing snow in an environmentally friendly way, even at higher temperatures. Your refrigerator and freezer are examples of appliances that use heat pumps to regulate temperatures.

"One of the main aims of the project will be to find out how we can produce snow regardless of the outdoor temperature, and to develop energy-efficient ways of doing it," says Petter Nekså, an energy research scientist at SINTEF.

Nekså thinks that one feasible approach is to develop heat pumps where the cold side can be used to produce snow, while the warm side is used for heating.

"If the air outside is cold, traditional snow cannons work very well. But these are temperature dependent," says Nekså. "At higher temperatures, you need a refrigeration plant to make snow. The advantage is that the process is independent of air temperatures."

What can make the process energy efficient is heating a building with the heat generated by the heat pump as it cools water to be made into snow, Nekså says.

"In this way, we can heat indoor facilities while also making artificial snow for ski slopes outside -- virtually cost free," he says.

Using heat and cold from heat pump technology

The approach involves adapting current heat pump technology, says Jacob Stang, one of Nekså's colleagues at SINTEF.

"A traditional snow production facility that makes snow at zero degrees outdoors has no 'hot side'," Stang says. "That means we need a heat pump that has the properties of a refrigeration plant. We have to adapt components, such as an evaporator and condenser, to get them to work together."

Storage and use

The project will be conducted in collaboration with the city of Trondheim, where SINTEF and NTNU are based, and the Norwegian Ski Federation (NSF).

The researchers are also hoping to develop better ways of storing snow, which is an approach many ski areas use as a hedge against warmer temperatures. Currently, many ski area use sawdust to store artificial snow that can be spread on slopes and trails when the weather doesn't deliver the white stuff on its own. While this is a proven approach, over time the sawdust loses its insulating properties and has to be replaced.

The project will also identify new ways of making sure that ski areas get as much benefit as they can out of manufactured snow. The researchers will look at everything from the design and drainage of ski runs, to protection from sun and rain, salting and snow preparation.

Technology transfer from the fisheries industry

Researchers will conduct lab experiments, use computer models and simulations, create prototypes and undertake field tests.

"Norway has a long tradition and expertise in this field," says Trygve M. Eikevik, a professor in NTNU's Department of Energy and Process Engineering. "The fishery sector produces around 300 thousand tonnes of ice each year for fish export. This is enough to cover an 8-metre-wide, 150-kilometre-long ski trail with a layer of ice that is 0.5 metres thick. It is more than possible to manufacture snow for skiing."

The NSF hopes the project will increase the chances that Norway will be able to host World Championships in skiing in the future, but officials are most concerned about maintaining skiing as a pastime in Norway. Communities across the country promote skiing by maintaining easily accessible, lighted and groomed ski trails and encouraging ski clubs. This strong system recruits young people to skiing, which has led to Norway's prominence in both alpine and cross-country ski competitions. It also helps keep people healthy, by encouraging them to get outside to exercise in the winter.

"The challenges posed by climate change represent perhaps the greatest threat to ski sports. This is why we're very pleased that this project is taking off," says Marit Gjerland, who is a ski run consultant for the NSF. "Good results from the project will mean a lot for the future of ski sports."

She says the technology could also expand the popularity of skiing, by making snow available in places where it previously wasn't.

"Just like we have artificial football pitches, we could also create future snow parks," she says.

Research centre for snow technology

One of the aims of the project is to establish a snow technology research centre based in Trondheim, where both Norwegian and international projects could be carried out.

"We envisage the development of more efficient refrigeration plants and snow production concepts, facilities designed for combined snow and heat production, and a total concept that integrates data models with meteorological data," says Eikevik.

"We hope this will help promote innovation and business development related to future snow production facilities," he says.