Ep42: Thomas Nowak 'Pumping Heat'

“People get a more comfortable life. And you contribute to better indoor air and outdoor air…”: Thomas Nowak on heat pumps.


In this episode of Cleaning Up, Michael Liebreich talks to Thomas Nowak, Secretary General of the European Heat Pump Association.

Heat pumps are likely to become increasingly prominent over the next decade, with some people arguing that the UK alone will be installing 3000 per day over the coming decade. Thomas explains heat pumps in simple terms, before Michael asks why the technology hasn’t become as well-known as other renewable solutions.

This is an abridged transcript of the conversation, edited for clarity.


Michael Liebreich: Thomas, it’s a great pleasure to have you on Cleaning Up. I've been looking forward to it because we have a range of different people on the show, we had Tony Blair for example. But we get to geek out every so often. To start, what is a heat pump? How does it work?


Thomas Nowak: I'm very happy to be here. First, let me explain heat pumps the way I did for a fourth-grade class when my daughter was in primary school. It's two effects that you need to understand. One is evaporation, the other is compression. Evaporation is like when you jump into a pool, you come out and the wind blows over your skin, you feel cold, the wind evaporates the water. Now, if we could catch it again and put it into a bicycle pump, we could pump, pump, pump, and you could touch the tip of the bicycle pump and it would get warm. So, now the skin is your one heat exchanger, and the tip of the bicycle pump is your second heat exchanger. Now you must ensure that you bring in the energy from the outside, from the first heat exchanger into the house via the second heat exchanger. That's how it works, and it is very reliable.


ML: Okay, so let's talk about some of the advantages, like efficiency. It just seems like heat pumps break the law of energy. You put in one unit of electricity, but you get three or four units of heating. I mean how can that possibly be?


TN: You take one unit of electricity and then, not magically but with thermodynamics, from the compression effect you get three to four units of heat, and then you can disseminate them into the building. So, we are not creating energy. That's not possible, as you certainly know. But we are using the energy from the compressor electricity and from the ambient, and we combine the two, and that brings us to a higher level.


ML: It's almost like we're using the electricity to simply move heat around. I mean, you could almost call it a heat pump, right?


TN: Yes, if you wanted to be smart and ingenious, you could do that. I checked with my experts this afternoon, and we can say that if with the heat pump is in a renovation project, you can probably get an efficiency of around a factor of three. So, one unit of electricity gives us three units of heat. If you built a new house, you should end up somewhere at four and a half, maybe even five. The best things I have seen is six, sometimes seven, but then you only do heating. And the efficiency is not the only benefit the heat pump by its design can now balance the electric grid. They also have no emissions, both CO2 emissions and particulate matter. They use local available energy, so you don't have to import fuel to run them. Finally, they provide local jobs.


ML: The heat pump sector carries a lot of baggage. There are misconceptions, partly because historically they weren't very efficient. Maybe they were noisy and if you wanted to use one, you would have to replace your radiators because the working temperature was so low. If you're used to running your radiators at 60 degrees and suddenly you come along and say, Well, we can only get to 40 degrees, you need bigger radiators. So, there's a lot of these things that perhaps were true in the past. Are things still complicated?


TN: The problem we have now is if you want to put the heat pump in, you need to have a little bit more knowledge than just replacing the existing boiler with a new boiler. And for that, we need some experts. They are available, but sometimes people are not willing to pay for that.  Heat pumps are also less visible than electric transport: you buy an electric car, your neighbors see it, you buy a heat pump, nobody sees that.

There is a bit of a shortage of understanding, but not only with the decision makers, the end user decision makers, but also with policymakers. I had to go through a list of critical of obstacles where people would say heat pumps don't work at all, that was the first one, heat pumps don't work when you use air as energy source… So then that then people say, no only new buildings, then they said, okay, single family houses only, but not multifamily, then the discussion was around the industrial applications. Now we have ended up at a situation where people say okay, but they are too expensive. So, of course, the opponents say that they are they are too expensive and they will break the electric grid.


ML: Will they? This coefficient of performance, this magic free energy, it's less when the temperature drops: and we have this thing in the UK called the Beast from the East, within a couple of days, you suddenly get these huge temperature drops. It only happens once every three, four, five years. But if you can't heat the homes during the Beast from the East, then a lot of pensioners will die. Because they will get hypothermic, their homes are not well insulated, and will have terrible mortality potentially.


TN: First, you will not have millions of these heat pumps from today. So, we have 10 or 20 years to accommodate the grids for that. We’ve done it in the past, and we can do it again in the future. With the rise in electromobility at the moment, the grids will be reinforced to completely different numbers than we have them today. And let's look at what happens really, if it would get cold from today to tomorrow, I think three-four days is already an adjustment period. That is quite long. But if it would happen very fast, the heat pump is not dropping out, the heat pumps operate at minus 10, minus 15 degrees centigrade, they are not operating at the same efficiency, but they are still operating. So, it would not be that that your elderly people that you mentioned would just freeze inside their home. If we make up a really nasty scenario, then you maybe heat only one room, then you put on another sweater. You would not die and the house would not cool down to sub-zero temperatures.


ML: What I'm hearing is that there are issues that at the very least require number one planning and number two investment. The grid as it stands today could not cope with millions of heat pumps in any European country. The opponents of heat pumps would argue that we should be using hydrogen because in most of Northern Europe, particularly in the UK, we already have pipelines and gas distribution networks to every home. Why do something so complicated with heat pumps? We should simply pump hydrogen through these pipes, change the burners, maybe the boilers, but that's relatively feasible.” Why are we doing this complicated thing with lots of expensive investment, when we could do something much simpler?


TN: Let me say that I'm not so sure that it's going to be much simpler. But the argument that I find more important is that if you go for the heat pump, you also offer people a more comfortable life afterwards. If your argument is let's not invest into the building core, let's simply replace the boiler, that means the building stock stays where it is. I have frozen at dinners in Edinburgh and London. The UK has this notoriously bad building stock. It's not like your house, it's these houses where you possibly manage to heat one room to 22 degrees, but not every room. If you look at the whole building, and optimize that, and then make it ready for heat pumps, you could say that's a byproduct, but you give people a more comfortable life. And you contribute to better indoor air quality and outdoor air quality because you avoid the emissions that are coming from combustion.