Research and Theory
Utilization of excess heat for snow production
The text below is a summary of one of the “Snow for the future” research projects. The author is Ole Marius Moen – email@example.com. The project can be categorized as a mapping task, where the focus has been to find:
- Which heat-driven cooling technologies exist and can be used for snowmaking?
- How much energy will heat-driven snow production require?
- What are the potential sources of heat?
- Which winter sport venues can potentially use this type of snow making technology?
Climate changes will lead to warmer temperatures and less natural snow. A likely consequence is that it will become more difficult to provide good conditions for snow sports. The ski season may even disappear in many typical “snow villages”. Since the traditional snow production method using snow lances or fan-guns require temperature below zero degrees Celsius, many locations, especially at low elevation, may not be able to use this method in the future.
Temperature independent snow production
One alternative is to use technologies that can produce snow in warm temperatures, so called temperature independent snow production. Today there are several providers of this technology, and it is used in several places around the World. The systems are costly, and require that the snow is distributed since the production takes places in a central location. Compared with traditional snow production, the technology demands up to 50 times more energy, which leads to high electric bills.
One solution for reducing the operational costs is to replace the electricity with heat as the energy source by using refrigeration technology driven by heat (for example absorption refrigerators). To produce snow using heat requires temperatures of around 90 – 100°C. Compared to using electricity, heat-driven cooling is relatively inefficient, since large parts of the heat can not be utilized. To be economical, such a solution is therefore dependent on being able to use cheap or free excess heat. This will also contribute to reducing the environmental footprint compared to snow making using electricity.
Potential heat sources
In Norway, studies have shown that one can find considerable amount of unused excess heat, especially in industry and waste incineration. In the industry there is potentially up to 10 TWh of available heat at the right temperature range, while for incineration about 1 TWh is not utilized for district heating due to low demand in the summer. Making use of heat from these sources is however not without challenges. The low temperature of the district heating in the summer makes it difficult to use for snow production, and external use of excess heat from the industry is demanding and not common. Both cases will require relatively expensive equipment for heat exchange both for user and provider, and pipes for transportation of the heat between the two.
- District heating (also known as heat networks or teleheating) is a system for distributing heat generated in a centralized location through a system of insulated pipes for residential and commercial heating requirements.
Co-location of venues and heat sources
Snow production using heat as the energy source for snow production, it is advantageous that the heat source and the ski location is within a short distance; neither heat nor snow can be transported efficiently over long distances. In Norway, the co-location of winter sport venues for Cross-Country biathlon, ski jumping and alpine, and potential heat sources has been mapped. This shows that 76 out of 168 mapped venues are located in a municipality with district heating or available excess heat from industry. For many of these venues increased snow production would lead to increase skiing since they are located in densely populated areas or are already popular ski destination venues.
Based on calculations with Granåsen, Trondheim as model example, an annual consumption of 1,5 GWh for snow production would contribute to lengthening the ski season with more than 1 month by being able to snow cover the stadium, 3 km of courses and the ski jumps. At the same time, the calculations showed that different factors can significantly alter the energy requirements. The model calculations will therefore be unique for each venue.
It is suggested that further research focuses on large venues with existing nearby district heating. Techno-economic analyses to concretize each individual venue’s potential may give us answer to if heat-driven snow production is a practical, economical and sustainable solution for future winter sport.
- Techno–economic assessment or Techno–economic analysis (abbreviated TEA) is a methodology framework to analyze the technical and economic performance of a process, product or service. TEA normally combines process modeling, engineering design and economic evaluation.