Colruyt charts course for 100% hydrocarbons in stores

Founded in 1925, the Colruyt Group is one of Belgium’s biggest retailers – with annual revenue of over €9.1 billion. Employing over 29,000 staff, it boasts 516 shops. Three shop formats in Belgium have product cooling: Colruyt supermarkets (237), OKay convenience stores (120) and Bio-Planet (19) organic stores.

The Colruyt Group’s official target is to reduce relative CO₂ emissions by 20% by 2020 compared to 2008 levels. With the Belgian retailer having already switched to electricity from 100% renewable sources, refrigeration now makes a proportionally larger contribution to its carbon footprint. Choosing a right refrigerant, therefore, is crucial for meeting its sustainability targets.

Becoming HFC-free

The Colruyt Group’s ultimate goal is to become HFC-free. In 2012 it launched a feasibility study. This led to the adoption in December 2014 of the official target of using 100% natural refrigerants for all its cooling needs.

Accelerate Europe met Project Engineer Collin Bootsveld. and his team at the Colruyt Group’s headquarters in the town of Halle near Brussels. “By end 2016, we will no longer build HFC cooling systems in our stores. The final ones are being built right now, because we couldn’t change our planning,” Bootsveld explained.

“We were already adopting natural refrigerants before the EU F-Gas Regulation came into force. The F-Gas Regulation was not the primary driver, but it does give us an extra stimulus,” he said.

After considering which natural refrigerant would best match their needs, his team opted for propane (R290) for in-store cooling. “It’s not that we think CO₂ is bad. After an honest evaluation, we think propane is the best solution for us,” Bootsveld said.

His team installed their first propane system in an OKay store in Roeselare in 2013. It took a year to secure the necessary paperwork – even though the 14kg of propane was housed outside. “We couldn’t go through that 40 times a year to comply with the regulations,” he said.

The current blueprint is based on two or three small refrigerant circuits each with a maximum propane charge of 2.5kg, and a secondary system that uses propylene glycol to bring the cold to where it is needed.

At the system’s heart are compact chillers containing less than 2.5kg of propane. With a refrigeration capacity of 30 to 50 kW, one chiller can cool the smaller OKay and Bio-Planet stores. The Colruyt supermarkets need to run two compact chillers. An extra chiller is always added redundantly, ready to step in should the other fail. Using a smaller refrigerant charge means they can be placed inside the store. 

The principle of the plug-and-play system was devised in August 2014. The system was first installed in a Bio-Planet store in Mons in November 2015. It has since been installed in three further Bio-Planet stores in Hasselt (January 2016), in Jambes (February 2016) and in Braine l’Alleud (April 2016). 

No more new HFC systems for cooling from 2017 

“We are going to accelerate this. We will not place any more HFC systems for cooling in the three store formats – Colruyt, Okay and Bio-Planet – from 2017 onwards. That is a board-level strategic decision,” said Julien Meert, a project engineer in Bootsveld’s team.

Colruyt’s chest freezers have been using the natural refrigerant R600a (isobutane) for over 10 years. They are stand-alone, giving store managers flexibility regarding layout. Pictures on the lid depict what’s inside, so customers do not need to open them to discover their contents.

High outside ambient temperatures are of little concern. “Propane installations can easily handle it. Our system was designed to operate in temperatures of up to 35 degrees Celsius, but we’ve recorded 42 degrees in Braine l’Alleud and it’s still running fine,” Bootsveld said.

All new Colruyt Group cooling installations will use natural refrigerants from 2017 onwards. Currently there are 50 to 60 new refrigeration systems in the pipeline, a mix of new shops and refits of existing stores. “At the current pace we will be ready in 2027,” he says.

During the visit of Accelerate Europe, a third-generation propane system was being tested at the Halle headquarters. Offering 20% more refrigeration capacity yet smaller than the previous configuration, the third-generation system was first installed on 1 September 2016 at a Bio-Planet in Huy. Factory-assembled for ease of installation, it will be rolled out across all store formats.

Leapfrogging HFOs

Many companies are responding to f-gas regulations by adopting synthetic refrigerants – so-called HFOs. Why did the Colruyt Group opt for natural refrigerants instead?

“We briefly considered HFOs, but we decided not to go there because we wanted to target our resources on natural refrigerants. If we had spent time on HFOs, it would have delayed the introduction of propane,” Bootsveld says. 

“Any intermediate step is exactly that – an intermediate step. We’re working on a ten-year schedule to remodel all our shops by 2027, so we can’t go for an intermediate solution,” he explains.

Mindful of F-Gas Regulation deadlines, Bootsveld is surprised by the conservative nature of many technology manufacturers. “We’re not going to invest in new technologies that use old-fashioned refrigerants that will need to be replaced by 2020,” he says.

The decision to leapfrog HFOs in favour of natural refrigerants was a no-brainer for Bootsveld. “We’re switching from 100-150kg of R507 to a few kilograms of propane – we’re going from a GWP of 4,000 to three. And we’re going from a leakage rate of 5% to [negligible].”

This is an excerpt of the full story. Please click here to read the longer version in the autumn issue of Accelerate Europe.