Author: John Aalberg

The SINTEF Energy research team is presenting ways to create snow in warm temperatures while optimizing the energy consumption.

This research memo presents a case study evaluating temperature independent snow (TIS) production as a component in an integrated energy concept. This concept utilizes waste heat from the snow production process as heat supply to buildings. A borehole thermal energy storage (BTES) was also a part of the integrated energy system. The BTES would be charged during the TIS machine’s operation time and discharged when the machine is not producing snow. Different production strategies were investigated where among others the energy efficiency was assessed. Four different cases were evaluated using a TIS machine with different approaches. The amount of snow produced laid between 14 600-20 000 m3. A utilization rate based on the produced heat was estimated to range from 67-95 % for the different cases. By integrating the snow production and building heating system, energy savings up to 131 MWh_el or 31 % was obtained. The size of a possible BTES would range from 16 to 57 boreholes depending on when during the year the snow was produced.

SINTEF Energy Research is part of the Snow of the Future project

The closing seminar for the research project “Snow for the Future” was held on October 26th, 2022 at Granåsen Sports Park in Trondheim, Norway. The seminar gathered experts within R&D and Universities, Skiing Federations, Site developers and industries. Also present was the constituted CEO/Sport Director for the FIS Nordic World Ski Championships (WSC) Trondheim 2025, Kristin Mürer Stemland. She presented the high ambitions that WSC Trondheim 2025 aim for, such as efficient and climate friendly snowmaking included in their Snow safety plan.

Topics like temperature independent snowmaking, snowmaking from surplus heat, energy efficient and integrated energy solutions for snowmaking are a few of the research areas covered in the workshop.

The presentations and videos from the seminar can be downloaded here (see also the “Seminars” optionn on the top menu on our homepage).

Due to increasing average temperatures in many areas of the World, snow production is now a necessity at most ski resorts.  Snow production requires, in most cases, high amounts of electricity for pumps, compressors and snow fans.  With the high cost of electricity in Europe this year, there has been a clear focus on how to optimize the snow production.

There are a few obvious ways of reducing electricity costs, for example by using a water source (lake or reservoir) that is higher in elevation than where the snow is produced.  In this way gravity will create parts of the water pressure that is required for a snow fan to work, thus decreasing the size of and electricity needed for pumps.

Other potential cost saving measures is to use additives that will increase the amount of snow that is otherwise produced with a fixed amount of water. A water additive can raise the temperatures at which water begins to freeze thus causing water to convert from liquid to solid faster and closer to the nozzle of the snow guns.  

A short-term snowmaking study (side-by-side test) conducted at the Kirkwood Ski Resort in 2014 by the Vermont Energy Investment Corporation and analyzed by the Brendle Group engineering company showed significant benefits by using water additives:

• The overall volume of snow produced increased almost 90%

• Water consumption decreased by 45%

Such results will obviously cause significant savings in energy, water and capital cost.

A summary of the Snowmaking study can be found here.

The Western area of US and Canada are experiencing a great early start of the ski season 2022/23. The former Olympic Nordic venues in Salt Lake City, Whistler/Vancouver and Canmore are either already making snow or have opened for excellent groomed skiing due to both snowfall and cold temperatures (see photos).

In today’s challenging climate there are still ways to guarantee snow, even when the temperatures are not conducive to freezing at the competition venue.  The hard part is to do this in a sustainable and climate-friendly way, and without too much cost.

Below is a list of seven different ways of covering the competition venue’s courses or slopes (in the event lingo called Field of Play – FOP), with snow.  Only the first two methods require local temperatures below freezing.  This list may also be ranked in terms of cost (money and labor).  The majority of the methods would need to transport snow onto the FOP, and must therefore use additional resources (fuel, etc.)

1. Natural snow fall
2. Traditional snowmaking with snow fans or snow lances
3. Collecting ice, then crushing this to “become” snow
4. Using snow stored from last winter
5. Making ice or snow with temperature-independent machines
6. Making snow inside tents, buildings or tunnels where the temperature is cooled down sufficiently for snow fans or snow lances to work
7. Transport snow from high mountain locations

Using ice to ski on

Using ice to ski on

The two first methods on the list above do not need any further explanation.  However, as the third method suggests, several large ski organizers have used ice instead of snow for all or parts of their courses for international skiing competitions, even at a World Cup level. Well known Cross-County World Cup venues such as Holmenkollen and Rybinsk have tried this, and several of the Chinese Cross-Country venues pre-Olympics 2022 used crushed ice that was tilled down with the grooming machines.

Holmenkollen collected ice shavings from a couple of the Oslo city’s ice rinks to mend a few thin spots on their 50 km course, while the World Cup organizer in Rybinsk transported large ice-cubes from the nearby rives and drove snowmachines across the ice around their 2.5 km course until the surface looked and felt like snow.  In China, both at venue and training centres, ice cubes from mountain lakes were transported, then crushed before pushed out and groomed.

Almost all ski event organizers would like to know and say long in advance of the event that they can absolutely guarantee sufficient and safe snow coverage for their competition courses. But, due to challenging weather and climate the last few years, very few organizers can with ease do this anymore.  Snow guarantee has become an increasingly important element in event and venue planning and budgeting.  This website will in the next few articles explore how different organizers have in the past and are currently solving the challenge.

To be able to host a World Cup, World Championship and Olympic & Paralympic Games, the organizer or venue must have or install an efficient snowmaking system or/and provide sufficient snow storage that can be proven to provide enough snow to cover the homologated /certified competition courses (called Field of Play in the Olympic lingo). The last known organizer that got away without having this was the 2010 Olympic and Paralympic Organizer in Vancouver who could provide 30 years’ records of snow-depth that showed an average depth of 2.62 meter snow on the Cross-Country and Biathlon stadiums during the Games time in February. The Games were held on 1.5 meter deep natural snow.

Most organizers of high-level ski events today have some kind of traditional snowmaking system in place.  This consists of snow fans or/and snow lances that create mounts of snow along the competition courses or hills or that are created in a central location and transported out or on to the courses/hills.  An increasing number of venues are now supplementing their traditional snowmaking system with snow collected at the end of the last season and stored over the summer.

There are however a few other ways of guaranteeing or providing snow to ski on.  Remember, snow is frozen water, and several venues and event organizers have explored and are using creative methods for their events.  We will cover some of these in the next articles.

This web-site and Snow for the Future are partnering with the venue and organizer for the 2025 Nordic World Skiing Championship in Trondheim, Norway in creating a plan for how to guarantee snow for this low-altitude venue.  In the next years leading up to the Championship, we will cover the details of the plan as well as how it was implemented.

Idrefjell in Sweden is already now in May ensuring that next ski season can open in October. Photos taken from their web site (http://www.idrefjall.se/)

Due to climate change, there is an increased interest in technologies for producing snow at ambient temperatures above zero, so called Temperature Independent Snow (TIS) production. This study compares two such technologies; a plate ice machine, originally developed for ice production to the fishing industry, and a flake ice system already installed at several ski locations. Since TIS production technologies are more energy demanding than conventional snow production systems, such as snow guns and lances, the comparison was focused on energy consumption.

Energy consumption

When comparing energy usage of various technologies, it is important to compare data for the  same operating conditions, i.e., ambient temperature and feed water temperature. The flake ice machine allows operation between -5°C and +25°C ambient temperature, and a feed water temperature between 5°C and 20°C, but the energy usage is only presented at 15°C and 5°C (design point), respectively. As seen in the table below, at that operation point the energy use for the plate ice is very similar.

Potential improvements

Operating window: The value of offering a wide operational window versus a higher, and more constant, energy efficiency should be considered. Also, the most probable operating condition for market introduction should be identified to optimise the design, i.e., minimise the energy usage.

Heat recovery: To recover waste heat from the snow production process is an energy efficient solution for installations with a nearby heating demand. Such a concept is available for the plate machine.

Efficient storage: To store the produced snow as ice plates, and crushing it before usage, could enable a more efficient storage due to a slower melting process. Thus, it can be stored at higher temperature for the same time period, or at a lower temperature for a longer time period.

Author: Cecilia Gabrielii, SINTEF Energi

In the last few years, there have been big discussions around the use of materials that are leaving microplastics and other potentially damaging components in the snow, for example fluor waxes as well as cover materials used for snow farming, glacier protection etc.

A natural fiber snow cover material that is 100% biodegradable is now on the market, and has gained big interest from both governments and ski-resorts.

SNOW & ICE POLAR

FLEECE GREEN®

A 100 % biodegradable nonwoven geotextile

The super ecological world novelty in the field of glacier protection, snow farming and snow depots. This geotextile cover material is available in grammages from 300g/m2 to 1200g/m2.

Snow & Ice Polar Fleece Green® consists of a 100% renewable natural fiber, is 100% biodegradable and sustainably compostable upon disposal.

The raw material comes from EU manufacturing and EU sources.

You would think that preparation of the snow surface for an Olympic Games competition is done by professional groomers in the newest computerized grooming machines.  However, for those of you involved in outdoor sports, you know the weather can throw a last-minute wrench in your wheels, such that all the modern machines become useless and old fashion smarts or equipment can save the day.

During the 2022 Olympic Games at the Cross-Country and Biathlon venues in Zhangjiakou the wind became our wrench.  Just minutes after our meticulous grooming the wind would blow snow onto the competition surfaces, filling in the classical tracks or creating uneven snow across the wide competition trails.  We would delay the grooming closer to competition start, but the skiers and the wax technicians needed a couple of hours to test the snow, the skis and the wax, giving the wind plenty of time to do its damage.

This is when our light grooming equipment and our manual techniques came into use.  Snowmobiles with light grooming attachments create a much smaller and lighter footprint than a large grooming machine, and do not affect or alter the snow surface nearly as dramatic. 

Often light tilling or milling of the snow is all it takes to crate an even skiing surface, even dragging a piece of fence along the three biathlon finish lanes helped create a fair sprint in case of a tight race (see photo below).

Of course, snowmobiles with rollers and the famous “Ginzu groomer” were more efficient in the last-minute preparation of the longer course loops and the entire stadiums.

Leaf blowers were handy in removing the snow that the wind had filled in the classical tracks with.  With the light snow in the cold Chinese temperatures, removing the snow by blowers were much more efficient than any other way.

The key to successful grooming for big events is to have all types of grooming equipment ready to go!