Skip to main contentSkip to navigationSkip to navigation
Sainsbury’s is trialling a new, low-energy refrigerant in its Portishead store in Somerset.
Sainsbury’s is trialling a new, low-energy refrigerant in its Portishead store in Somerset. Photograph: Alamy
Sainsbury’s is trialling a new, low-energy refrigerant in its Portishead store in Somerset. Photograph: Alamy

The natural refrigerant set to reduce supermarket energy use

This article is more than 9 years old

A new waste product derived from sugar beet could help cut supermarket energy consumption from refrigeration

Could the sugar you have in your morning coffee help prevent global warming?

Sainsbury’s thinks the answer is yes and is putting the question to the test in its Portishead store in Somerset, where it is using a refrigerant derived from waste sugar beet in its fridges and freezers.

Not only does the CO2-based refrigerant, called eCO2, have a global warming potential of one – 3,922 times less than R404A, the refrigerant most commonly used by supermarkets – it is also derived from a more sustainable source than other CO2-based refrigerants, which are often derived from hydrocarbons or ammonia.

Paul Crewe, head of sustainability for Sainsbury’s said he was interested in eCO2 when he found out that British Sugar, Sainsbury’s main sugar supplier, derives the CO2 for the refrigerant from waste sugar beet in its refinery in Norfolk.

“One of the things we are very keen on is real life examples of circular economy, putting every single product in our supply chain to good use. This is an opportunity for CO2 from a product that goes into Sainsbury’s [sugar] being deployed into one of our refrigerant systems to prove that it does the same job as other derived sources of CO2,” said Crewe.

New EU rules

So far 200 Sainsbury’s stores have refrigeration systems that use CO2, but it is far from alone. A survey of north European supermarkets by Carrier Commercial Refrigeration found 65% of respondents had begun to opt for non HFC refrigerants, with CO2 the choice for 83% of those who had already converted.

This has been driven, to an extent, by new EU regulations on the use hydrofluorocarbons (HFCs). The EU wants to cut F-gas emissions (fluorinated greenhouse gases) by two-thirds by 2030 (pdf) and the use of R404A, which is one of the worst offenders, will be banned in new commercial equipment from 2020.

But an absence of HFCs doesn’t make CO2 a “green” refrigerant. Rob Parker, operations manager for A-Gas, a UK refrigerant producer, said most are derived from processes that use fossil fuels. “Most CO2 refrigerants are recovered from dirty industrial processes that are far from green in their methods.”

In contrast, the CO2 in eCO2 is derived from the production of bioethanol, using sugar beet that is not destined for sugar production. “Because the sugar beet consumes CO2, just like any other plant, during photosynthesis locking it up in the sugar, when you ferment it you produce CO2 as a byproduct,” said Parker.

A better choice?

But it is not only eCO2’s green credentials that have won over Sainsbury’s. John Skelton, the supermarket’s head of refrigeration, points out that it also has half the moisture content of alternative CO2 refrigerants.

“Moisture is the enemy of refrigeration systems,” said Skelton. “When it gets to a low temperature, moisture freezes and will stop refrigerators working. And when the refrigerant is CO2 it can also cause corrosion.” Corrosion was a major concern for Sainsbury’s as it considered making the leap to CO2, as there was no technology on the market to measure moisture presence in its refrigeration systems. But it worked with A-Gas to develop a testing mechanism for moisture content, an industry first. And it was during those discussions that Skelton heard about eCO2.

If the experiment at the Portishead store continues to prove successful, Crewe said, Sainsbury’s will roll out the use of eCO2 in all its stores using CO2 refrigerants.

Parker says A-Gas could make enough eCO2 to supply the entire UK refrigerant industry if there was enough demand. So what is preventing other supermarkets from following Sainsbury’s lead?

While Skelton said eCO2 is “cost-neutral” with rival CO2 refrigerants, Parker points out that the switch from using R404A, which most supermarkets use, to CO2 will involve putting in more expensive fridges and freezers (with of course an additional resource impact). They may also be more difficult to maintain.

But with the new F-gas legislation set to progressively restrict the supply of R404A and other HFCs in the coming years, Parker said, the prices of traditional refrigerants are expected to rise.

There are other green spin-offs from using CO2. The Carrier report found that CO2 refrigerants outperform HFCs in energy efficiency. And since more than 40% of the average supermarket’s energy consumption comes from refrigeration, over 14 years energy savings make up for the higher capital cost, the research suggested.

For Sainsburys, eCO2 will also help it reach its commitment to cut its CO2 emissions by 30% by 2020 (pdf). “From a CO2 perspective, this is a great story,” he said. “We’re going to continue to explore the potential to use natural [CO2] refrigerants where manmade [HFC] refrigerants are used, such as in air conditioning and ground source heat pumps,” he added.

The technology and innovation hub is funded by BT. All content is editorially independent except for pieces labelled “brought to you by”. Find out more here.

Join the community of sustainability professionals and experts. Become a GSB member to get more stories like this direct to your inbox.

Comments (…)

Sign in or create your Guardian account to join the discussion

Most viewed

Most viewed