How do we get our ice rinks on the path to net zero? And what systems in a rink are the biggest contributors to carbon emissions? The Mayors’ Megawatt Challenge (MMC) presented its roadmap findings from a 9-rink pilot in the Greater Toronto Area earlier this month. Surprisingly, of all the moving parts that are required to keep good ice in these large refrigerated boxes, resurfacing accounts for 17% of the total CO2 emissions.
We know our REALice floodwater system reduces an arenas’ energy spend substantially, resulting in lower CO2 emissions, reductions which we also calculate. However we didn’t know how much of an impact this measure can have compared to the other systems, like the ice plant itself, HVAC, the dehumidifier, etc.
And now we do.
As well, installing a cold water resurfacing system was specifically identified a high impact measure by the MMC, saving, on average, 21.7 tCO2e. That’s a very compelling number for such a simple retrofit — and a big reason why every ice arena should be making the switch away from hot floodwater resurfacing now.
So why is resurfacing third highest cause of carbon emissions in an arena? That’s because of how the ice is traditionally maintained.
The ice is built using around forty thousand litres of water (10,000 gallons) that is spread on the rink’s refrigerated slab (or sand base) in fine layers that freeze. Along the way to building a sheet of ice that’s around 3 cm (1 1/4″) or more thick, white paint, face-off circles, lines, logos and creases are added.
Once the skating begins, that’s when the big resurfacing energy spend begins.
The Big Resurfacing Energy Spend
Ice makers have been using extremely hot water to maintain the ice — a practice that’s been going on for half a century, or more. The hot floodwater that’s poured into the ice resurfacing machine, at temperatures as high as 60°C (140°F), delivers a sheet of ice that isn’t fragile because it contains fewer air bubbles compared to cold water straight from the tap. Those air bubbles, if left in the water, creates ice that is fragile and creates a lot of snow — making it hard to skate — and hard to keep the puck flat, especially in the dying moments of the 3rd period.
The capacity of a typical ice resurfacing machines’ floodwater tank is about 5 times bigger than your bathtub at home. Heating that amount of water each time an “ice make” or “flood” is done, can require thousands of litres of hot water each day — all depending on how many ice makes are needed. If you have more user groups using the ice, more floods will need to be done. Busy arenas can see as many as 15 ice makes a day – even more. That’s a lot of hot water.
It’s not just heating the floodwater that contributes to an arena’s CO2 emissions, either, but reducing the natural gas spend – the fuel typically used for water heating – makes a huge difference. Electricity, made from non-renewable sources such as coal, is also a contributor. According to National Resources Canada, almost 82% of electricity in Canada came from non-greenhouse-gas-emitting (GHG) sources (2018), like hydro, nuclear, solar and wind. Coal, despite accounting for less than 7% of total electricity generation, was responsible for 63% of electricity-related GHG emissions, in Canada, in 2018. Which province the arena is located in makes a big difference to the CO2 emissions an arena is responsible for emitting.
When that hot floodwater is put on the ice, the refrigeration plant, powered by electricity, kicks in to remove that heat from the ice, getting it to freeze. That process is done with brine/glycol lines in the concrete slab that are set to particular freezing temperatures. Those temperatures, as well as the floodwater temperature, the thickness of the ice and the ambient temperature in the arena — are all contributing to how quickly the floodwater will freeze, and how long the ice plant will run.
The 3D-printed REALice system acts as a de-aerator but without the same expenses as hot water. Using only water pressure to remove the micro air bubbles from the water results in an even denser, harder, clearer ice than its hot water cousin. And because the treated cold water has improved heat transfer properties, the water freezes faster. To maintain the same quality ice as before, a higher brine/glycol reset is needed which is typically 1.5°C (3°F) higher — or more. Those higher settings result in lower operational costs — and much lower run time hours on the compressors. It will also result in lower CO2 emissions.
Simple Retrofit, Paradigm Shift
Without any moving parts and no required maintenance, the REALice wall unit is easily integrated in the plumbing system right before the fill station for the ice resurfacing machine. It’s a simple retrofit measure, and comes with an expected life of more than 15 years, a measure that will keep working, and treating the water, day after day, year after year. A Swedish invention, the first REALice system was installed at the Malmo Arena in 2006 and has been working, treating thousands of litres of water, every season since.
As to ice quality, the ice made with REALice will be at least as good as ice made with hot water — but those higher brine resets (slab or infrared) will need to be made. REALice is paradigm-shifting technology: using cold water instead of hot, and warmer ice temperatures compared to before. We ask our customers to watch what the ice is doing. If it is brittle and creates a lot of snow, the ice is still too cold. If the water takes too long to freeze, it’s most likely an indication that the ice is too thick – or there are underlying issues with the ice plant. Bryan Hawn, Supervisor of Arena Operations at the City of Vernon, BC (pictured above at the Kal Tire Arena) – who has converted all the City’s indoor rinks to REALice, says it can be a challenge to get the staff “on board” because they’re so used to flooding with hot water.
“I tell them that it’s not about our process being broken,” Hawn explains. “It’s about a new process to reduce the cost of making and maintaining the ice.”
I tell them that it’s not about our process being broken. It’s about a new process to reduce the cost of making and maintaining the ice.Bryan Hawn, Supervisor of Arena Operations, City of Vernon, BC
If the ice is maintained as it should be and those higher temperature settings are achieved, the ice will produce a lot less snow, fewer scars and gouges — and it will result in ice that plays faster. That means happier user groups – cleaner tape-to-tape passes, and pucks that stay flatter, even towards the end of the 3rd period!
Worldwide, there are over 600 REALice ice rink installations – and that number is growing. Those range the gamut from small, seasonal facilities like the Servus Community Arena in Bow Island, Alberta (pop. 1,983 – pictured left) to busy year-round multi-pad facilities like the 3-pad Sardis Sports Complex in Chilliwack, BC. Earlier this year, for the 2020-21 season, the East Coast Hockey League (ECHL), a mid-level professional men’s league, awarded its “Best Ice” trophy to the Rapid City Rush, playing out of The Monument in Rapid City, SD – on ice made with REALice. Engineering manager Nathan Kleinschmit, pictured below, says on-ice maintenance was also reduced, which was a blessing with the workout the ice would take with the league’s revised schedule of three games in three days.
“We just didn’t have the wear and tear on the ice like we had before,” Kleinschmit explains. “The ice quality was just there.”
That ice quality was something the officials obviously recognized.
“One official told my boss it was the best ice he had been on since he had been officiating in this league for years!” he says.
Lower CO2 emissions, lower costs — and great quality ice. It’s why our customers tell us time and time again that it’s a “no-brainer”. If you’d like to know more, ask me. I may also be able to point you to utility incentives and government programs that will make your simple payback even faster than the usual 1-2 years for a busy year-round pad.
About the Mayors’ Megawatt Challenge
Since 2003, the MMC has been bringing together municipalities of every size from across North America to lower energy use, emissions, and operating costs in their own facilities, while demonstrating leadership in climate change action within their communities. Seven municipalities – the Cities of Toronto, Halton Hills, Barrie, King, Brampton, Markham and the Town of Caledon participated in the roadmap to net zero pilot. You can watch the entire presentation here.