Large heat pumps can provide approximately 10% of Europe’s industrial heat demand. Big dairies, slaughter houses, breweries, chemical companies and paper manufacturers are obvious candidates because of their significant demand for both heating and cooling. But there are obstacles to overcome
Size matters:
Most attention on decarbonising heating and cooling systems is focused on the easier task of homes and offices, but the European Heat Pump Association believes heat pumps can also help industrial processes reduce their carbon emissions Cows:
Slaughter houses are full of hot animals, this heat can be captured, then used to warm water needed to clean up the mess Milk and cheese:
Cooling and heating processes in dairy plants are ideal to convert to heat pump technologies Key quote: “
People are not energy traders, they are providers of beer, milk and cheese. Even if we can improve energy efficiency, they may not want to make changes as they do not want to risk their production process. They do not trust that we can do what we say, they cannot see how it is possible”
Large heat pumps can help decarbonise industrial heat demand in Europe, says the European Heat Pump Association (EHPA), a Brussels-based lobby group. This is around 2000 terawatt hours (TWh) a year, states Eurostat data. “We assessed different temperature ranges and came to the conclusion that large heat pumps can technically provide around 10% of that,” says Thomas Nowak, secretary general at EHPA. Large industrial heat pumps, classified as having a heat output capacity above 100 kilowatts, are particularly advantageous in industries with demand for both heating and cooling, such as dairies and slaughter houses. “When slaughtering an animal, you get waste heat from the body and you can use that to heat water,” says Nowak. He continues matter-of-factly: “Mammals have a body temperature of around 37°C. Meat needs to be cooled. You can transfer the heat from a room full of dead mammals by air. Then you blow that air over heat exchangers and cool it down. The heat is then inside the refrigerant cycle and can be upgraded, for example to 80°C, and used to warm water for cleaning.” The same is true of a dairy plant, says Nowak. “Every time you cool milk, you can use that energy to make hot water, which can then be used for cleaning and disinfection.” A similar logic can be applied to the production of yoghurt and cheese, where different processes, such as pasteurisation and growing bacteria, take place at various temperature ranges, making it ideal for applying heat pump technology, he adds.
Norwegian dairy
One company that has taken the plunge is the Tine Ålesund dairy group in Norway. Since June 2018, it has been using heat pump technology to convert surplus heat from district heating into process steam, which is then used by the firm. This has allowed the dairy to replace 12 gigawatt hours (GWh) of natural gas a year with district heating, reducing carbon dioxide and other greenhouse gas emissions by up to 66%. It is using machinery created by Olvondo Technology, a Norwegian company, that can increase waste heat temperatures by 100°C up to a maximum of 200°C. Most, if not all, other heat pumps can only provide temperatures up to 100°C. “We are focusing on industries that use very hot water or steam in their processes,” says Roger Myrvang from Olvondo Technology. Helium is used to power its “high lift heat pump”. Helium is “non-toxic, inflammable and environmentally friendly,” says Myrvang, adding that its global warming potential and ozone depletion potential are zero at the point of use. The pump’s potential for saving energy is significant, believes Myrvang. “In Norway, there is a big focus on using excess heat instead of just throwing it away.” The company has received interest in its products from other countries in Europe and as far away as Thailand.
I nterest and obstacles
Food and drink processes, textiles, tobacco, paper and painting sectors have greatest potential to take full advantage of heat pumps as they all involve producing waste heat that can be re-used rather than being discharged into the environment. How well such a system would work in practice would depend on several factors such as climate and temperature ranges and the technology applied. “But it is absolutely possible,” says Nowak. Applying large heat pumps in industry is in its early days. Interest may be increasing, but there are still obstacles to overcome, not least scepticism and a lack of trust in heat pumps, which are still seen by many as a new and unproven technology. “People are not energy traders, they are providers of beer, milk and cheese. Even if we can improve energy efficiency, they may not want to make changes as they do not want to risk their production process. They do not trust that we can do what we say, they cannot see how it is possible,” adds Nowak. A lack of best practice examples and the fact many industrial companies have unrealistic requirements for a return on investment, often as little as two years, are hindering progress, says EHPA. The lobby group also wants a more favourable political environment, including a price on carbon and low interest rates and loan guarantees for energy efficiency investments, to encourage a switch to heat pumps.
Closed circuits
Danish engineering group Danfoss is ahead of the pack, getting 25% of its heating consumption at its 250,000 square metres headquarters and production facility site in Nordborg in southern Denmark from four large industrial heat pumps. As a producer of key components of the technology, it clearly has a significantly better understanding of it than companies whose core business has nothing to do with energy. In 2007, Danfoss started a programme to increase energy efficiency at its 26 largest factories globally, which account for 80% of the group’s total energy consumption. Part of the solution was installing the industrial heat pumps each with a heating capacity of 500 kilowatts. They deliver 25% of the site’s heat consumption and have helped reduce heat demand by 60% over seven years while carbon dioxide emissions are down by 2700 tonnes a year. “The pumps exploit the surplus heat in our process cooling water,” explains the company’s Torben Christensen. Surplus heat from pneumatic compressors is also reused in the heating system. “Like process cooling water, compressed air is also used in many industrial production processes and needs to be cooled when running. With the heat pumps we can recover the surplus heat from the cooling water and the air compressors and feed it into our heat system,” says Christensen. “Before we used cooling towers, which meant the heat disappeared into the air. Now we are circulating heating and cooling in a closed circuit.” The next step will be building a new data centre next to its Nordborg headquarters. From 2019, the servers should provide plenty of surplus heat, which can be used in Danfoss’ own heating system or transferred to the local utility. “Overall, our surplus heat from process cooling, compressed air and the data centre server will be able to cover 50% of our heat demand,” says Christensen.
Writer: Karin Jensen, Photo: Bo Mathisen
This article is part of a series examining how to decarbonise heating and cooling systems