Increasing interest for CO₂ refrigeration – and not only from an economical perspective

Monday, February 17, 2020

It is no longer only the Scandinavian countries, who show interest for refrigeration plants with CO₂ as the refrigerant. More supermarket chains in England have also started to install CO₂ plants and it is also spreading to other European countries. Lately the Danish Danfoss sales company has experienced an interest from South American countries, who would like to learn more about how to build various CO₂ plants.

Illustration 1: The illustration shows average yearly temperatures in Europe and expected possible savings comparing to a plant with R404a.



Historically CO₂ plants have been seen as a Scandinavian phenomenon because it was considered that CO₂ was only feasible in relatively cold climates. However, it has become apparent that it can compete against traditional plants even in the warmest months in Denmark where there the energy consumption should be higher. 

It is however not only Danfoss who is of the conviction that CO₂ plants can be feasible in a lot of climates. Also the large supplier of refrigeration solutions to supermarkets, Carrier, is installing more and more CO₂ plants. In an article published on the website on the 7th of December 2011 they say that their studies show that Co₂ plants can be feasible in climates with an average temperature of up to 20-26°C. They further more say that in 2012 they will start tests on their second generation of transcritical CO₂ plants to prove that these plants are at least as energy effective as traditional HFC plants in all European climates. 

The below illustration, which shows the expected possible savings in comparison to R404a pants has often been used to evaluate the feasibility of a CO₂ plant, will probably need to be revised as CO₂ plants will most likely be feasible under all European climates. 

The new interest, that Danfoss is experiencing, is not based on instant economic savings or profitability but more from an environmental aspect. The two South American countries - Chile and Brazil, from where the installers came to Danmark to learn more about CO2 plants, have climates which hardly make CO2 plants profitable from just an energy consumption perspective. Further more these countries do not have duties on the environmentally damaging refrigerants as for example R404a, duties that are implemented in many European countries. 

The driver behind the interest for CO2 in Chile and Brazil is on the contrary a focus on the environment. There is from the society a large focus on the fact that we have to show more consideration to the environment in many different processes. Therefore the installers experience an increasing interest for CO2 plants from supermarket chains, because this will make them able to reduce their "Carbon Footprint" considerably. This also gives the supermarkets the opportunity to profile themselves with a green profile. 

In Denmark the installers experienced, how it is possible to use CO2 in supermarket cooling and also in cooling of big distribution centres with a capacity op up to 1.5 MW. The type of plants were both cascade and transcritical plants.

The primary concern of the installers in regards to CO2 was the high pressure which is necessary in these types of plants. But after they saw the plants and learned about the different solutions and the development the plants have been trough they felt better equipped to return to their home countries and start building CO2 plants. Because of the climates in Brazil and Chile the most profitable type of plant would probably be a cascade plants. Examples of booster and cascade plants can be seen at the end of this article.

From a broader perspective there are more advantages with a CO₂ plant than just the economical profitability that you get up front together with less damaging impact on the environment when you compare CO₂ with HFC. 

  • In the cooling process a CO₂ plant develops an amount of heat which gives you the possibility for heat reclaim, which can be used for heading of the remaining buildings.
  • The heat surplus can also be used for heat driven air condition systems (sorption) which can then be used as air condition in the buildings.
  • As many synthetic refrigerants are imposed with a duty or are in the risk of having duties added companies who switch to CO₂ will also be minimizing the economical risk linked with using a refrigerant regulated by political measures.

Establishing a CO₂ plant today is slightly more expensive than a traditional HFC plant but there are indications that the prices are becoming more alike

What are the environmental "savings"?

By changing to CO₂ the yearly potential for environmental “savings” can be illustrated with an example from a Danish supermarket chain. The example is calculated on approximately 800 stores with a number of different plant sizes: 

  • Yearly leakage (10% of the plans charge) equal to approx. 18 mio. kg. CO₂
  • Yearly energy savings with CO₂ (10%) equal to approx. 1 mio. kg. CO₂
  • Total yearly reduction of apx 19 mio. kg. CO₂

If this is converted to driven km in a modern car, releasing 99 g. CO₂ per km. (eg Golf Blue Motion) this equals: 

  • 193 mio. km. or
  • Almost 13,000 cars yearly emission at 15,000 km/year

Danfoss is a global leader within energy efficient solutions which help to reduce CO₂ and thereby fight the global climate changes. Today Danfoss already offers many solutions that can reduce the amount of CO₂ released into the atmosphere. You can read more abut the solutions on the international web page, where exciting articles on technologies within cooling of food, air conditioning, regulation of electrical engines, heating of buildings and solutions for renewable resources. Technologies that can help fight the climate changes and also make modern living possible in the future.

You can read more about Myths and Facts in relation to CO₂ plants on the international Danfoss website

Example of cascade plant