Fremme HVAC‑løsninger med elektrokaloriske materialer

Den massive energietterspørselen fra HVAC

Modern industrial society uses a lot of energy. One application we tend to underestimate when it comes to energy usage is cooling and heating. Det utgjør mer enn halvparten av verdens totale energiforbruk, foran elektrisitet (20 %) og transport (30 %).

Så kanskje enda mer enn elbiler er elektrifisering av HVAC (oppvarming, ventilasjon og klimaanlegg) og å gjøre det mer effektivt avgjørende for å redusere energiforbruk og karbonutslipp. Spesielt ettersom etterspørselen etter kun kjøling forventes å tredoble innen 2050 på grunn av økonomisk utvikling i varme land med store befolkninger som for eksempel India og Indonesia.

Source: Daikin

Inntil nå har den foretrukne teknologien for å oppnå høy‑effektiv HVAC vært varmepumper som bruker kompresjonskjøling.

A new technology is now coming to challenge the status quo, based on a physical principle called “electrocaloric cooling”.

Hvordan varmepumper fungerer

All varmepumper, from compression heat pumps to future electrocaloric heat pumps, function on a basic principle: moving heat instead of generating it.

This is a very different principle from fossil-fuel-based and other electric heating systems, in which either electricity or gas/coal/oil is consumed to produce heat.

A heat pump, instead, takes heat from one side of a wall and transfers it to the other side. In winter, it absorbs heat from the outside and sends it into the building. In summer, it reverses this process to cool down the building and works like air conditioning.

Moving heat is a lot more efficient than generating it. This allows a compression-based heat pump to generate 2-4W of heat/cold for every W of power consumed.

Source: RMI

The heat is moving in and out of the environment, with the 2 main options being using outside air or the surrounding soil through underground piping.

Heat pumps are most often used to heat and cool down buildings like offices, commercial spaces, and homes. However, it can also be used in an industrial setting, reusing energy sources from one industrial process into another, leading to massive energy savings here as well.

Source: Sintef

Elektrokaloriske varmepumper for å gå utover kompresjon

Fremgang innen elektrokalorisk teknologi

Traditional heat pumps use the thermal effect of compression & decompression to move the heat from one point to another. This requires refrigerant agents like hydrofluorocarbons or ammonia which have either direct or indirect greenhouse effects on the climate.

The electrocaloric principle is different. An electrocaloric system heats when exposed to electric fields, as it causes atoms to align in a single direction, reducing entropy. The reverse happens, causing cooling when the electric fields stop.

Source: Fraunhofer IPM

Elektrokaloriske effekter har vært kjent siden 1960‑tallet, men den gang var den sterkeste temperaturforskjellen som kunne oppnås kun 2,5 °C.

Some progress was made i 2006 da en tynn film av bly‑titan‑oksygen‑zirkonium oppnådde 12 °C kjølekapasitet.

However, the recent breakthrough of almost 21°C temperature change, achieved by researchers of the Luxembourg Institute of Science and Technology in Belvaux, shows that the technology is becoming powerful enough for commercial applications.

Elektrokalorisk prototype

The team used a polymer and lead-scandium-tantalum-oxygen (PST) multi-layer capacitors (MLC).

Source: UPCommons

The Luxembourg researchers have created a prototype that achieved maximum cooling when under 10V per micrometer of power, creating a maximum cooling of 4.2W.

Source: Techspot

This is a radical improvement from all previously developed methods, with temperature span and cooling power, respectively, 50 % and 15 times larger than the previous best electrocaloric devices.

This puts the prototype leagues ahead of all previously tested electrocaloric concepts.

Source: UPCommons

Source: UPCommons

The material was also tested for repeated heating and cooling cycles and has shown no sign of degradation.

Among the many advantages of electrocaloric systems is that the direct use of electricity makes EC coolers compact in volume and suitable for miniaturization. So, besides future heat pumps, it could also be used in small electronics and batteries.

It also has very high efficiency, potentially much higher than the compression heat pump system can hope to achieve.

Videre forbedring

The research published in the journal Science describes a prototype. Some further improvements are discussed as well.

For example, the current prototype uses dielectric fluid rather than water to prevent short circuits. However, this dielectric fluid has poor thermal properties compared to water.

So, developing waterproof multi-layer capacitors (MLC) could significantly improve the speed and cooling capacity of the system.

Increasing the number and density of MLCs could also result in more cooling potential.

Finally, thinner and flatter electrocaloric modules would help, and it is not clear if applying higher electric fields is possible and safe.

Avanserte varmepumpebedrifter

There is currently no company commercializing electrocaloric heat pumps or cooling systems. It is still very much an academic and applied physics field.

However, it is likely that now that the technology is evolving at a level of efficiency, making commercialization viable, these research institutes will look to monetize their patents.

So, it could be interesting to look at the leaders in the heat pump industry who could benefit from licensing the IP for electrocaloric devices.

It is also likely that the creation of commercial-grade electrocaloric systems and their distribution to end users will be a very capital-intensive process, favoring the largest actors in the industry.

1. Carrier Global

Carrier er en leder innen HVAC (kommersielt og bolig), kaldkjede, og brann‑ og sikkerhet, med over 58 000 ansatte. Selv om de ikke kun selger varmepumper, er dette en produktkategori som er selskapets fokus og som de ser på som fremtiden for industrien.

Den er hovedsakelig fokusert på Amerika, med HVAC som utgjør mer enn halvparten av salget.

Source: Carrier Global [securities_stock_price_tag symbol="CARR" exchange="NYSE"]

Den har en installert base på over 330 000 kommersielle HVAC‑systemer, 33 millioner bolig‑HVAC‑systemer, 1,8 millioner kjøleutstyr og over 90 millioner brann‑ og sikkerhetssystemer.

Selskapet er fast bestemt på å drastisk redusere sine klimagassutslipp (GHG) innen 2030.

Med tanke på at mange av disse utslippene kommer fra ammoniakkjølemidler, gir muligheten til å bytte til et elektrokalorisk system i fremtiden industrien en vei videre hvor de eneste utslippene er knyttet til energiforbruk og metallutvinning, som vil bli drevet av fornybar energi.

Source: Carrier Global

2. Daikin Industry

The Japanese company founded in 1924 can claim to be the world’s number 1 air conditioning company.

The company has been active in the heat pump space since 2006 and has established as early as 2008 a business alliance with Gree Electric Appliance, China’s top air-conditioning manufacturer.

It is mostly selling in the Americas, Europe, and East Asia, but has experienced explosive growth in markets like India as well, with a 23x increase in sales between 2009 and 2022.

Source: Daikin

One of Daikin’s competitive strengths is its R32 coolant, with a much lower effect on global warming than its competitors.

This means that the emergence of electrocaloric systems might be in the short-term a threat to the company’s competitive position.

Source: Daikin

But at the same time, it reflects the company’s preexisting focus on the environmental effect of cooling systems and innovation capacities (it invested $300M in a new R&D center in 2015) and would make it a good candidate for developing these systems at commercial scale.

A strong indication of Daikin’s dedication to eco-friendly innovation is the worldwide free access to basic patents for R32 since 2015 and free access in 2019 to all the group patents since 2011.

3. NIBE Group

Investors interested in the prospect of heat pumps and electrocaloric systems might want a company fully dedicated to the sector, without the distractions and risks associated with other technologies.

In this case, they might be interested in Nibe, a European manufacturer of heat pumps, as well as wood stoves (another carbon-neutral heat source).

The company is originally from Sweden and still conducts a large part of its sales in Nordic countries, as well as Europe. It had 21,333 employees in 2022.

Source: Nibe

The company’s heat pumps have avoided the emissions of 360,000 tons of CO2 in just one year.

As a more focused company, Nibe is as big as Daikin or Carrier when it comes to heat pumps alone.

With research about electrocaloric materials ahead in countries like Luxembourg and Germany, this could open the way for European companies like Nibe to establish privileged relations with researchers and be among the first to expand their offer beyond compression-based heat pumps.