Danfoss Report Advocates For New Ways To Put Waste Heat To Work
Danfoss is a Danish company founded in 1933 by engineer Mads Clausen. Today, it employs more than 40,000 people worldwide. Its primary business is manufacturing heating and cooling equipment, but it is also deeply involved in designing and producing power control electronics. It advocates in a white paper published recently for capturing waste heat and using it to heat our homes, businesses, and factories.
CleanTechnica readers know a thing or two about efficiency. We know the electric cars we love are far more efficient that those powered by internal combustion engines. We subscribe to the message in books like Drawdown and the advice of people like Stanford professor Mark Jacobson that tells us the secret to a sustainable world is to electrify everything and power it all with renewable energy.
But there is another side to the “Electrify Everything” story. Every device powered by electricity generates heat when in operation. Every time an elevator rises, a refrigerator runs, or a server switches code packets at a data center, heat results. In a new report, Danfoss criticizes the rush to import millions of gallons of LNG to Europe to offset the loss of methane gas from Russia. It says there is a better, cheaper, and more sustainable way — recapture waste heat.
“Using gas or electricity for heating is like using a chainsaw to cut butter, as heating can easily be covered by low-value heating sources such as excess heat,” Danfoss says. That’s a pretty extraordinary statement. Here we thought if we just run everything on electricity, the climate crisis would be solved but apparently we need to adjust our thinking. Here’s the gist of the Danfoss white paper.
“Wasted energy often comes in the form of excess heat and is a byproduct of most industrial and commercial processes. Factories, data centers, wastewater facilities, and supermarkets all produce vast amounts of excess heat. In the European Union alone, excess heat amounts to 2,860 TWh a year — almost corresponding to the EU’s total energy demand for heat and hot water in residential and service sector buildings. Much of this excess heat could instead be captured and used.
“We already have the solutions available today. What we need now is the political will to make it happen. The greenest, cheapest, and safest energy is the energy we don’t use. Structural efficiency measures, including regulation to reuse excess heat, are almost absent in the political responses to the crisis. This is the case despite the fact that efficiency measures constitute the fastest and most cost-effective tool to mitigate the energy crisis. Most remarkably, only very few initiatives have pushed for more efficient use of the vast amounts of wasted energy in the form of excess heat.”
“Waste heat can be reused through existing and well proven technologies, most notably heat pumps, which are electrically powered devices able to transport heat from one place to another. They can, for example, harness heat from the exhaust fumes of a factory or the heated water from the cooling systems in data centers and circulate it in the heating system of nearby homes.
“Reusing excess heat will lower costs for consumers. It is much cheaper to reuse energy than it is to buy or produce it. On a societal level, excess heat can replace significant amounts of electricity or gas that are otherwise needed to produce heat. This way, excess heat can help stabilize the future electricity grid. Paraphrasing Amory Lovins, using high value energy carriers like gas or electricity for heating is like ‘using a chainsaw to cut butter’, as heating can easily be covered by low-value heating sources such as excess heat. In the future, new excess heat sources such as Power to X facilities will emerge and grow in number, generating large amounts of excess heat that can be utilized on a large scale.”
I was unsure what “Power to X” technology means. Even though I write for CleanTechica, this was a new term for me so I decided to follow the advice of my old Irish grandmother who, when asked what something means, would always say, “Look it up!” So I did and here’s what I found, courtesy of Wikipedia. [Note: I support Wikipedia with a donation of $5 a month and I encourage others to consider doing the same.]
Power-to-X (also P2X and P2Y) is a number of electricity conversion, energy storage, and reconversion pathways that use surplus electric power, typically during periods where fluctuating renewable energy generation exceeds load. Power-to-X conversion technologies allow for the decoupling of power from the electricity sector for use in other sectors (such as transport or chemicals), possibly using power that has been provided by additional investments in generation. The term is widely used in Germany and may have originated there.
The X in the terminology can refer to one of the following: power-to-ammonia, power-to-chemicals, power-to-fuel, power-to-gas (power-to-hydrogen, power-to-methane) power-to-liquid (synthetic fuel), power to food, power-to-syngas, and power-to-power. Electric vehicle charging, space heating and cooling, and water heating can be shifted in time to match generation, forms of demand response that can be called power-to-mobility and power-to-heat.
Collectively, power-to-X schemes which use surplus power fall under the heading of flexibility measures and are particularly useful in energy systems with high shares of renewable generation and/or with strong decarbonization targets. A large number of pathways and technologies are encompassed by the term. In 2016 the German government funded a €30 million first-phase research project into power-to-X options.
The Waste Heat Research Behind The Danfoss White Paper
Brian Vad Mathiesen, a professor in energy planning and renewable energy systems at Aalborg University, led the research cited in the Danfoss white paper, which builds on his team’s previous Heat Road Map Europe projects. “The amount of cities, regions and countries in Europe which waste heat while spending billions on natural gas or electric heating is mind-blowing,” he tells The Guardian, and warns that Europe’s energy security is at stake.
“Take the Netherlands. There is virtually no district heating even though there is almost twice the amount of waste heat compared to the heat demand. Denmark is the same size but has towards 60% percent district heating with only one third of the population. The use of waste heat is certainly not connected to technical differences. While the physical laws are the same, the political will and traditions are very different.”
He adds there is “huge, unharnessed potential” in the excess heat produced by heavy industry, such as chemical manufacturing, steel, and cement production. In the EU, that amounts to more than 267 TWh a year, which is more than the combined heat generation of Germany, Poland, and Sweden in 2021.
What Are We Waiting For?
Kim Fausing, the president and chief executive of Danfoss, believes recycling heat is a crucial step towards a sustainable world. “If businesses were to harness all the excess heat from these data centers, the emissions savings and revenue from selling this heat would be highly significant. In Greater London, we have identified at least 648 eligible excess heat sources, including data centers, underground stations, supermarkets, wastewater treatment plants, and food production facilities. Why aren’t businesses and local government organisations using these?” He points out that London’s excess heat amounts to 9.5 TWh a year — enough to heat 790,000 households. “Reusing excess heat offers incredible opportunities for businesses throughout the UK to reduce their emissions, save money and make money. What are we waiting for?”
The Danfoss white paper is long and detailed and is chock full of specific plans for how various industries could take advantage of the waste heat that is there and just waiting to be harvested. Sections of the report also reference projects in many places around the world where Danfoss waste heat capture technologies have already proven successful. It’s a report that is well worth reading.
The Takeaway
Kudos to Danfoss for amplifying the research done by Brian Vad Mathiesen on the potential to use waste heat so precious electricity and fuels can be put to a higher purpose. This seems to be an example of plucking the low hanging fruit that is there for the taking. So why isn’t more being done to advance this technology?
A reasonable guess would be that the fossil fuel industry is more interested in selling fossil fuels to heat homes and businesses than it is in promoting a sustainable planet. Since the industry has its tentacles deeply embedded in the political process in every nation, governments are being guided toward what is best for Big Oil rather than what is best for the planet. The real answer may be to get better political leaders. As somebody once said, “If the people will lead, their leaders will follow.”
Update: We reached out to Professor Mark Jacobson of Stanford University for his input on this story. Here’s what he had to say:
“Most waste heat comes from combustion of coal, gasoline, diesel, and natural gas. Since we want to eliminate these fuels by transitioning to 100% wind-water-solar (WWS), those sources of waste heat will disappear. Another source of waste heat is computer data centers. In advanced data centers, this waste heat is already captured by water cooling systems. At Stanford, the heat captured by water is sent to a district heating/cooling system, where the waste heat is transferred to a boiler for later use.
“I’m sure there are still many data centers not doing that, so that is one area where waste heat can be captured. With millions of electric cars, there will also be additional waste heat, but that waste heat is much less significant than the waste heat of gasoline and diesel cars, since electric vehicles use 1/4th the energy as gasoline or diesel vehicles. In any case, it is extremely difficult to capture such waste heat, let alone store it. There may be some industrial sources of waste heat upon electrification of all energy. If there are near a district heating system, then the heat can be transferred there just like with the Stanford system.”
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