Zwei Päpste sind normalerweise recht selten; wir haben sie gleichzeitig persönlich bei uns:
Prof. Dr.-Ing. habil. Michael Kauffeld ist ein deutscher Kältetechnikpapst, leitet an der Hochschule Karlsruhe (HKA) das Institut für Kälte-, Klima- und Umwelttechnik (IKKU), außerdem lehrt und forscht er seit 22 Jahren an der HKA. In der Kältetechnik engagiert er sich weltweit seit 1986 für natürliche Kältemittel.
Prof. Björn Palm ist Professor am KTH Royal Institute of Technology in Stockholm in Schweden und der internationale Wärmepumpenpapst.
Zusammen geben sie eine Einführung in die Funktion einer Wärmepumpe und geben einen Ausblick über aktuelle Forschungsthemen und Zukunftstrends.
Am 19.6. ab 15:40 Uhr sind sie zu Gast an der Fakultät Elektrotechnik und Informationstechnik der Hochschule Karlsruhe. Sie sind Gastredner im Seminar Erneuerbare Energien, das auch als Livestream auf YouTube übertragen wird.
zum Studium Erneuerbare Energien: https://www.h-ka.de/bachelor/energietechnik-und-erneuerbare-energien
zur Playlist der Veranstaltungsreihe: https://www.youtube.com/playlist?list=PLhvRytfP7Y4Lp4EMKdCNobAcCYOZqYxTx
okay I [Music] here so it’s a special pleasure for me to welcome Professor BJ Palm from the Royal Institute of Technology in Stockholm if I’m right and I just have the pleasure to hand over to you maybe you introduce yourself a little bit and we looking forward for your presentation thank you thank you very much so uh good afternoon everyone it’s a pleasure to be here and to be able to talk to you today about uh very important important subject I think importance of heat pumps in the future energy systems and I understand that many of you are studying electrical engineering so I think you would like what I’m saying uh I we have divided now the presentation here so I will give sort of an introduction why heat pumps are important and then Michael will talk about more about the the how it a heat pump works so my presentation will be rather easy to understand I think for everyone and uh just to tell you who I am I come from the Royal Institute of Technology in Stockholm and we at Department of energy technology and we have a group called applied thermodynamics and Refrigeration so we we have been working on heat pumps and Refrigeration equipment for almost 100 years uh yeah I think that is enough as a background now let’s see yeah we have the right slides here so uh just to give you an an idea about the an overview of what I’m when I talk about I will basically focus on this first part here reasons for increasing the number of heat pumps what is a problem what is the solution and what are the obstacles and then Michael will continue and we’ll see how far we get in this part this is actually a shorter part even though it looks longer in the on the slide here so what is the problem uh the problem is this I don’t know if you have seen this before but this is the carbon dioxide side concentration in the atmosphere during the last 450,000 years and as you can see the level has always between been below 300 PPM and even if you would go much further back in time you would see that we have never had so high concentrations as we have now and the increase is very very rapid this slide is from 2013 and you can see that only during this 11 years since then uh the new red dot up here is a lot higher up than uh the end of the line here so the CO2 concentration is increasing very rapidly and this of course results in increasing temperatures in the world so these are the temperatures uh during the last 2,000 years more or less and uh of course we don’t have data from the old times no temperature measurements but we can find out in other ways what the temperatures have been and U how do we know that we actually are behind this that the human activities are the cause of this uh increase well we have models nowadays which we can use to to predict the temperature in the world depending on different uh factors and with with this program we can also see what would the temperature have been if we did not have emissions of carbon dioxide for example and other greenhouse gases and as you can see here in the um let’s see here if we did not have carbon dioxide emissions and other emissions we would have had more or less the same temperatures that we had in 1850 but this is not the case so the models can show that the release which we have of CO2 is causing this increase in temperature and the last year has actually been a very dramatic year here you can see the temperatures in July worldwide since 1940 and you can see that there is a drastic increase and you can also see that in particular in 2023 the temperature increased quite a lot and this is not the only thing this is the sea temperatures sea water temperatures and down here you can see four different years since uh the measurement started more or less and then the red part here is the gap comparing the year 2023 to 24 compared to any other year before so there has been a drastic increase in the sea temperatures during the last uh year a little bit more than a year and this is of course very disturbing we we don’t really understand why this is happening either and that is even more disturbing then um so this is showing the temperatures last year and and uh actually last year was the warmest year ever recorded with a thermometer so to say uh and just recently there was uh a release of an article in nature stating that the temperature during 2023 was the highest in 2,000 years and how can we know that well one of the indicators we can look at as are the tree rings like you see on this picture to the right here so if the weather has been hot then the the trees grow faster and by that you can tell that uh the temperatures during the last 2,000 years has never been so warm as during last year yeah and of course we have some we can do some statistics on this and temperatures go a little bit up and down and the black curve here indicates uh the 5year running average so this BS behind compared to the red dots which are the actual measurements of daily temperatures and to the left you can see the scale here so it’s the the number of degrees above the pre-industrial levels would say so and you can see that even now we are reaching some days already 2 de above um pre-industrial levels so um I’ll come back to this sort of the levels and and what we would like to see or what we hope to see but the the dra drastic increase during the last year is definitely something which we need to worry about and uh this leads of course to different problems heat waves drafts wildfires and all of these are just headlines from different journals which I picked up from last year and uh so many different things happened during the year of 20 23 and this has continued into 2024 as well and U you can you have seen a lot of drastic changes due to this the ice shelf on the around the polar north North Pole is decreasing resulting in thawing of the permafrost which is releasing more methane from the ground for example yeah you have seen nice bears before this was from Germany is it one or two years ago when were these we had these floods and uh so many different things you can see in the in the news actually showing this in increase but there are also some things which we perhaps do not talk so much about and this photo shows migrants marching through Central uh America towards the US and you could ask yourself why are they marching towards us of course they want a better life but if they could sustain themselves in a good way where they lived from the beginning they would not have been moving and I’m not saying that it’s only because of climate change that they tried to get to the US but I I would say that this is one of the reasons and in the future when when some parts in the world will be uh more difficult to live in uh difficult to sustain yourselves in in those parts people will start moving and they will this will also cause uh social unrest uh which is something which we do not talk a lot about we we talk about floods and wildfires and all of these things but also the connection between global warming and social unrest is something I think we need to consider also for the future so what is the solution we have seen what is a problem what is the solution well we agreed all almost all countries in the world World agreed in 2015 to try to stop the global warming and this was done through the Paris agreement and uh what does that say well the Paris agreement says that we should try to limit the increase in global temperatures to less than 2° and preferably to one 1.5° and this diagram then shows what would be the uh effect of continuing business as usual continuing using uh fossil fuels in the same way we did before and the green line is what is required if we want to reach the 2 degree scenario and the blue line is what we or curve is what we need to do if we want to reach the 1.5 degre scenario and look now at the vertical axis here it is the annual Global total total carbon emissions so as you see already in the middle of this Century we will have to have negative carbon dioxide carbon emissions and that is I mean this this means that we really have to phase out all fossil fuels and we also have to do something to absorb the carbon dioxide which is already in the atmosphere and uh how we do that well that could be another lecture but there is something called carb carbon capture uh but it’s a technology which is being developed and yeah we we it is not sure whether we can use it to an large extent yet I would say so what has different countries agreed on most countries have a goal when they would be carbon neutral and as you see on this timeline here most countries have aimed for 250 as a as a year when they will be carbon neutral some countries will reach it a little M before and some countries have decided to try to reach it a little bit later and of course this depends on what conditions your country has uh if you have a lot of you’re depending a lot of coal right now you have a bigger problem if you have a lot of uh like Sweden a lot of U others natural resources which can be used like hydrop power and wind power then then it’s an easier problem to solve uh yes so will we reach our goals one uh report which came recently from the United Nations uh raises some concern about this it is perhaps not possible to reach the goals at least not if we keep at the pace we are working right now we need to do more and um actually in the guardian just a couple of weeks ago there was an article where they showed uh the result of interviews of a lot of people U lot of researchers doing research on global warming so each little square in in the diagram here represents one person and they should say when do you think what temperature do you think we will reach at the end of the century so the GL the goal according to the Paris agreement is 1.5 or 2° but as you can see almost all of the researchers thought that it would be more than 2.5 de or more so 77% of the climate scientists expect a rise of at least 2.5 Dees so even if we have the Paris agreement it seems unlikely that we will actually reach it and of course we should not give up just because of that it’s just to work harder we it’s important to work harder and if we don’t reach 2.5 perhaps we reach 2.6 or 2.7 I mean we must must continue working on this yes and in Europe what we do in Europe well we have uh we have a decided to have a goal but what does this goal include so to say so Wonder liion has said that I want Europe to become the first climate neutral continent in the world by 2050 and to make this happen we must make take both steps together and uh so several programs are launched U green deal is called and one part of the green deal is what is called fit fit for 555 and uh in this this is not 55 refers to to the 55% greenhouse gas emission reduction by 2030 and just last year these goals were also U made a little bit tougher so the improved Energy effic Efficiency was changed so that it should be 38% rather than just 32% and 42.5% should be renewable energy sources compared to 32 according to the old uh goal so just to put things in perspective let’s look at the gross available energy in the European Union 70% is actually still fossil and you can see that the green part here it’s actually increasing so Renewables are increasing but it’s going at a relatively slow rate and this diagram goes back to 1990 so if we should look ahead 25 years from now that’s uh some like something like half of this length to the right and at that time we should have uh phased out all the fossil fuels and we should also be carbon neutral or even even carbon yeah carbon neutral by by that time so we have a huge task to do here to reach the goals which you have set for ourselves so what is the strategy to reach these goals I will talk about only one share of the or an important share but of of the energy use and that is the energy use in the European building sector and uh looking in the into the statistics we could say that about 40% of all energy in Europe is used in in buildings it’s not only for heating or cooling it’s also for other purposes but it’s 40 about 40% and the energy use in buildings stands for approximately 37% of all greenhouse gas emissions and we have most I would say the most common way to heat buildings in Europe is to use uh gas heaters and we have according to different sources it could be about 100 million or 130 million space heaters in stock and uh a large share of these are old with relatively low efficiency so if we want to I mean the the lifetime of one of these heaters is about 25 years so it would take 25 years to to change all of these heaters to something more uh something better so you can see that the the European building sector has has can contribute a lot to decreasing the the carbon emissions I need to talk a little bit also about biofuels because one answer which is often given is that well we can burn biofuels instead but biofuels that’s basically forest or materials from from farming and about the forests of course the best way to decrease the carbon dioxide emissions would be to or carbon emission carbon levels carbon dioxide levels would be to allow the trees to stay in the Forest right not to cut them to use them for for firewood so there is a lot of discussions within EU right now how to treat this how how whether we should allow using firewood or not and just to show you one diagram about this the gray Circle here represents the the total energy used in you in the you and about 177% of this is U Renewables and out out to all of the Renewables including solar wind and boues the bio energy actually stands for almost 60% which is much higher than I thought before I saw this article and out of this 60% about 75% is used for heating and cooling so in in several countries firewood is still still an important uh fuel for warming the houses but we cannot expect to increase the Harvest of biofuels that’s my my my belief so it’s it’s questionable if you can Harvest bof fuels a lot increase the Harvest a lot and when we talk about biofuels we should differ also between wood and waste wood of course if we cut trees for uh paper or Timber uh we there there will always be some residues branches and roots and we could burn those use those as bof fruits but that’s only a small share and in the future when we try to phase out the fossil fues of course there will be much higher competition for the bofes so we can expect the price of biofuels to increase quite a lot compared to now and we should also remember that biofuels is a good starting point for producing liquid fuels for example for aircraft or for ships so perhaps we should not use it just for anything we should keep it for specific purposes as the resources are limited so the reality then in conclusion so far is that the fossil fuels will be phased out we have to phas them out the biofuels will not be enough to cover up for the fossil fuels which we don’t dig up anymore and the synthetic fuels like hydrogen produced from Renewables that’s an inefficient way to heat buildings at least could be used good for other purposes for industrial purposes for example but for just heating it would be very an inefficient way to use electricity uh and Renewables and nuclear well what do they what what is the outcome of those sources well it is of course electricity so this means that we are moving towards an electric Society we are also used to having pipelines and for gas and for oil but in the future we will have a lot of uh electric lines instead for transferring electricity and we will use electricity for almost everything we’ll use it to even to produce fuels sometimes even though it will it will not be efficient but we perhaps need fuels or we can know that fuels can be stored so for that reason we may keep it so and this is also the conclusion of the EU so electrification is one of the pillars so to say on the U that the European Union is basing its change of the uh future strategies on and of course electrification and heating that means heat pumps so extensive roll out to heat pumps is what is expected within the EU and you can read this in the text from coming from the EU in the residential sector the share of electricity in heating demand should grow to to 40% by 2030 and to 50 or 70% by 2050 and in the service sector the numbers should be even higher so that’s the expectations and uh similarly worldwide if we look at I EA that’s International Energy agency they do prognosis about energy use or change of the Energy System worldwide and they say similarly then that the proportion of heating equipment sales accounted for by heat pumps nearly triples by 2030 and continues to grow thereafter so Heat pums become leading Heating and Cooling technology in the building’s world wide by 2040 and in another other report just from U yeah from September 2022 they they state that we need about 600 million heat pumps by 2030 so it’s an enormous amount of heat pumps which should be pushed out on onto the market market and this just shows the trends up to now and how the change Trend needs to be changed in the sales of heat pumps to reach the goals which iea thinks that we need to reach to be able to be sustainable um then if we look at the sales of heat pumps it’s actually increased quite a lot so this shows the sales in Europe from 2013 up to 2023 and as you can see the growth is more or less exponential even though something happened in 2022 and that was the winter when we had extremely high gas prices extremely high electricity prices as well but at that that year a lot of heat pumps were sold so now we’re sort of back to normal again but the the TR the expectation is that this will increase so the top of the this graph is 3 million heat pumps here and if if you look at the expectations based on what has been stated from the EU you can see that we need another scale so to the left here you have 14 million heat pumps instead by and that is by 2030 or 2031 so you can look at different policy documents and you will see that the there is a drastic increase in the number of heat pumps and uh the numbers may be different in different sources but it’s something around this numbers which I show here um yeah this is one was another source also European Union they they in this Source they stated that we should be able to produce or sell 10 million heat pumps by 2027 so we were now at 2.5 million so four times as much by 2027 and uh this is um from the European heat pump association their expectation related to different countries and as you can see France is the country where they expect to sell most that most heat pumps will be sold Germany second and then you have Italy and Poland and the the rest of the countries in in Europe here but according to this their expectations and it should be able to should be possible to uh install 43 million heat pumps uh by 2030 so even more than what the European Union so to say Pro prognosed decided uh the European Union is also working on a heat pump action plan and this plan will then uh State some policies for in facilitating the installation of heat pumps this should have been taken before the EU elections and U it was unfortunately postponed so we don’t know exactly what will happen now but uh it will probably be taken later this year uh with the new parliament in place um but there are some countries where they already took decision so in France they have a national heat pump action plan and they have a plan of producing 1 million heat pump per year by 2027 so um they have Mak their decision already on this so of course some there is some resistance against installing heat pumps and this is mainly for economic reasons it’s more expensive to buy a heat pump compared to buying a gas boiler so the governments of Europe have introduced some uh measures to force homeowners to use heat pumps in the future rather than uh gas gas burners so this this map here shows which countries have band on fossil fuel boilers and it’s different to read difficult to read to the right there but of course it depends between the countries sometimes it’s from a specific date and these dates can be different sometimes it covers both oil and gas heaters sometimes it’s only oil etc etc but all of the colored countries here have some um some type of bans against fossil fuel boilers and acting in the opposite direction then is that several countries also have subsidies for heat supporting the installation of heat pumps so in the left you see the subsidies the countries which have subsidies in new buildings and to the right you see countries which have subsidies for renovations and obviously almost all countries in in the Europe have some type of subsidies for introducing heat pumps now if you look at the different countries you will see that they are uh they are very differently mature uh in their use of heat pumps so the different countries are seen on the left uh starting with actually the Scandinavian countries Norway Finland Sweden Denmark here and uh then you can see all the other countries below and what this graph shows what is the likelihood that a house owner would buy a heat pump rather than another type of heating system so in in Scandinavia it’s more than 90% chance that the buyer will select the heat pump while in the UK it’s only 3% chance that the buyer will use buy a heat pump and not gas heater so it’s a big difference here between the different countries and this is also something which we should recognize of course I talked about before the difference between heat pumps and gas heaters and the this shows and the difference in efficiency so a heat pump has a we call coefficient of performance so this means that for each unit of electricity you get four about four units of heat out so the efficiency is than 400% as you see here while a gas heater well it could never be more than 100% right but it could be sometimes less so according to the slide I showed before there there are many old heaters which have efficiencies of about 60% so and this influences of course the total use of energy because if we use energy more efficiently we can reduce the total amount so this 70 % fossil fuels will be reduced to a lower number so to say if we if you use electricity rather than than uh fossil fuels so it’s the same as electric cars we know that electric cars require less less energy than the ordinary fuel or diesel cars so uh finally what are the obstacles there are some problems on the way and one problem is the what we call F gases so heat pumps and Refrigeration equipment traditionally has used what used to be called Safety gases because they were not not flammable and not poisonous but they turned out to have bad effects on the environment we have heard about the ozone layer and we have heard we Al it’s also so that the newer uh refrigerants they have high global warming potential so we should try to get rid of them for that reason so just before we uh I talk about the different refrigerants I just want to point out that there are of course different types of heat pumps we have air water heat pumps the left column here and they could be located outside or inside or have be split units same thing with we could have water water heat pumps will either local localized inside or split or only outside or we can had air to a heat pumps so and these types of heat pumps uh they are manufactured in different countries and this has an effect on uh how much what type of refrigerants they are using so here we can see that the most common types has traditionally been air to a so it’s like this split air conditioning units you probably have seen many many times the sales of those are decreasing while the sales of air to water heat pumps are increasing and the water heater water to water heat pumps are decreasing a little bit but these airto a heat pumps they’re almost exclusively built in in Asia and they very rarely use natural refrigerants they use this old-fashioned synthetic fluids which have some environmental effects on the other hand the air water heat pumps they are typically built in in Europe there are many manufacturers of these also water water heat pumps so here there is a larger chance that these will be using some natural fluid so here we can see um the distribution of different fluids so r290 that’s another name for propane so that can be an is an excellent refrigerant um R32 is um a synthetic fluid which is has a little bit lower greenhouse warming potential than the old one r29 90 so R32 is increasing while R2 410 a is decreasing and then there are some others but of course uh I think both me and Michael here agrees that we should try to use natural fluids like propane in the future and that’s much of what our research is about so this is coming from an informatory note and it’s an estimate of the heat pump sold in Germany So when you buy a heat pump you have to apply for fun and thereby there when you do that you state what referent your heat pump will have so that’s a way of trying to figure out how many heat pumps of different types are sold different trents and we can see then that the propane heat pumps are actually in increasing in in numbers quite a lot and they reach now about 20% and while 410A is going down which is good that’s the old one R32 is still increasing but it’s sort of a change from this 410A so hopefully the propane heat pumps will increase a lot in the future we have also International agreements trying to phase out the use of f gases or these synthetic fluids so this is a a diagram showing how much the gvp weighted U maximum amount is uh in different parts of the world according to what we call the kigal amendment to the Montreal protocol but in Europe we also Al have new regulation from just a couple of months ago called the fgas regulation and according to this regulation we should face out all use of hfc so the most common use of common type of synthetic fluids there is another type which is called hfos which will be allowed in this not included in this phas out but also for these hfos lost remaining type of synthetic fluids there will be uh restrictions so small heat pumps less than 12 Kil small heat heating system or refrigeration systems will not be allowed to use uh hfos either so um yeah there is another problem and that is what is called paos you probably heard about that in the news uh there is a Teflon you probably know about and that is one of the P there is a a movie about when they found out that Teflon was actually not so good for the environment black Waters I think it’s called it’s interesting to see uh anyhow so the paos have negative effects on on people and on the environment uh that does not mean that all P has such effects but just to be uh sure there is a suggestion in Europe to phase out all pfos so um this will have a large influence on the phase out of these refrigerants which are synthetic so almost all of them are considered pfos so how will we handle the refrigeration refrigerant problem we will the synthetic refrigerant are strong greenhouse gases and they belong to the paas group and if they don’t they could also de compose into Pall and the phas out of f gases decreases the available amount of synthetic refrigerants and at the same time we want to increase in amount of heat pumps exponentially as I showed you before so this is you could say a problem we need to develop new heat pumps which can be run on on the natural fluids like propane and the natural alternatives they are flammable and they could also be poisonous if we talk about ammonia so uh this need to be handled in some way but we will have to learn to design Safe Systems with flammable refrigerants that is my my my belief and this is something we work on both Michael and and myself since many years so I think I will stop here uh and let you in here and talk more about the technical details thank you very much um let’s see working question to the audience you want to keep in English or uh you want to have it in in German or in [Laughter] Danish English is fine okay so then I continue and uh little bit different from what Bon said from me you will not uh you will also get some more details but you will also get an introduction to what the heat pump is because Sebastian uh told me that you the majority of the students as electrical engineers and you may not know what the heat pump is or how it functions and this is just to yes support what BJ said uh you can see here the buildings uh they are responsible for about 15% of the greenhouse gases in in Germany and this is what the International Energy ageny says they say that to the year 2040 which is not that far away um most of the savings come from either reducing the energy demand so making the buildings more energy efficient or changing electric heaters resistant heaters to heat pumps and the other part comes from renewable energies and the heat pump actually is uh considered to be re renewable energy let’s look at the heating system so here you have the the total CO2 footprint uh the numbers vary a little bit depending on on whom you ask or which uh Source you take but you can see here for a typical German household about 33 % uh of the the greenhouse gases or CO2 emissions come from the heating and and the hot water of course it can vary little bit Yeah if you have like I had some years ago one of our sons he could uh take a shower every day for like 45 minutes then maybe the the the CO2 contribution from the from the hot water or the warm water is a little bit higher then you can have different heating systems or different systems to systems to warm your hot water could be a an oil burner or gas burner and the gray cloud shown there the the smoke is an indicator of how much CO2 is released and you can see there that uh what is this down there Hite or pellet Castle it’s it’s very small uh and uh the heat pump it depends a lot on the cop over an entire year we will have a quick look at that in the next two slides if those numbers are correct the 2.5 for an air source heat pump or five for a water source heat pump and of course with the heat pump it depends a lot on where you get the electricity from if you make the electricity yourself with PV panels then it’s completely CO2 neutral uh let’s have a look at the coefficient of performance of a heat pump this is an investigation from fronhofer isse for existing building and this is for for a heat pump with air source and on the previous slide it said something of 2.4 if you look here at the bars the the light blue bars they’re all well above 2.4 so so probably this assumption on the slide before has to be corrected a little bit uh to a higher value for the air source seat pump and if you take water source seat pumps there the value was something around five the green bars here they’re all below five so that value has to go down a little bit because there’s a very bad or poor reputation for for airs Source heat pumps especially in Germany and that people always say oh you have to drill a hole in the ground you have to spend those €30,000 for for getting the the ground probes done yeah you don’t need that you can just use an air seat pump especially in area like here in K Ru where we hardly get any temperatures below 0 degre during the winter time any longer so uh put it here on this uh yeah you can see the table for the for the air source heat pump the CO2 emissions are probably lower than what is in this publication but for the Water Source heat pump it’s probably a little bit higher now looking at the fundamentals for the for the heat pumps you can see here that uh yeah this is the way it works so you take some energy from the ambient you put in some electricity to drive the compressor and then you can heat your house and it’s especially uh a renewable system if you get your electricity from either PV or or wind or some other Renewable Power heat pumps are nothing new U this is the first uh description of a heat pump I found it’s from 1855 uh from a guy called Peter R from rittinger they used or he installed heat pumps in in paper Ms uh and then the first like real heat pump patent I found is from 1912 from Switzerland and this heat pump the one from from Switzerland from this patent application is very similar to what we have today um so this is a kind of a ground probe but contrary to what we use today where we have um uh water glycol mixture here he wanted to evaporate the refrigerant there and this is something like my the professor who was the supervisor for my PhD he kind of invented this or reinvented this in the 1990s you can see here this was already 1912 U patented by someone so to have the refrigerant going into the ground and uh this is one of the the really installed heat pumps first ones this is from the the city hall in surich 1942 and another one four years earlier was 1938 if you think back of what uh happened at that time 1938 1942 this was World War II uh there was a shortage in in Coal uh for for Switzerland they couldn’t get it so they installed a lot of heat pumps in that time period we saw another Boom for heat pumps in the 1970s when there was the oil crisis we see like a third boom now uh and hopefully now it’s the the Breakthrough that the heat pump really will take over now if you have been asking yourself throughout this presentation from be and for me how a heat pump works U it’s just the opposite of a refrigerator and this guy is asking himself yeah now I turned my refrigerator upside down but it’s still not working as a heat pump um so let’s look how the heat pump functions we do have an evaporator similar to what we have in the fridge in the refrigerator it’s inside to cool your your butter milk or beer uh for the heat pump it could be in the ground as in this patent application from 1912 from Switzerland or can be inside the the heat pump and then you supply some uh some uh Heat the airort seat pump it would just be the outdoor uh air the refrigerant is evaporating and as BN has mentioned several times the best refrigerant for the heat pump nowadays would either be propane or could also be CO2 or ammonia depending on the application so we call this thing an evaporator or fumer in Germany in German uh and the pressure inside this vessel depends on the temperature and uh then of course we have to get rid of all the vapor we use a compressor for that this is electrically driven typically in a in a heat pump hermetic uh compressor is used and we discussed today when we walked through our lab be and I that the best compressor is one way just very compact of course uh and there are some nice developments from the automotive industry which could be used then we have to uh turn this vapor into liquid this is done in the condens and this is where the the heat pump is rejecting the heat to heat the the house or the water and then of course we have to connect this to make it a closed cycle and we use an expansion valve for that uh so these are the German names so the evaporator the compressor condenser and the expansion valve and here you have the energies uh this q. e is the heat we take from the environment then we put in some work into the compressor and then we get the sum of those two for heating our building and if uh the this coefficient of performance uh is is four it means that we get uh four the the this Q do c is four and like four kilowatt heating with one kilowatt electricity for example so this is a little bit more advanced and I think you you had the same drawing in your presentation or a very similar one um so this is how the the heat pump works and you can see can use air as heat Source or the ground or ground water this is how heat pumps look like uh it could be like everything contained into in one housing placed outside uh typically placed outside because you do have the the compressor and the compressor makes a lot of noise and you don’t want to have that inside your house uh a tip if you want to install an air source heat pump installed somewhere where the neighbor doesn’t see it because if the neighbor neighbor sees the heat pump he thinks it’s loud and noisy if he doesn’t see it he will never notice that there is a heat pump um and then this is a monolock system or this is water to water and these can be made very compact FR for isse they have uh developed a system with 150 g of propane you have an idea 150 gam of propane a hairspray can like a Hairspray the the larger hairspray cans like anyone is using it you have one in your bathroom probably 150 so how much how much propane is in the in the hairspray can or we can start with a lighter The Smokers among you how much propane butane mixture is in the lighter a little bit more about two 2.3 in the hairspray can you have 180 180 g propane and at FR e and fryborg they managed to build a heat pump 12 kilow heating capacity with 150 g so this is less than what you have in a hapr can and there are no restrictions where you place your hairspray can you can have it in the bathroom you can have it in the kitchen or in the basement but with the heat pump there’s a lot of discussion if it’s safe to use a propane uh heat pump now for the refrigerants these were the refrigerants in the very early days all natural fluids because there was no chemical industry uh then we got the CFCs they were used for virtually everything like when I tell my students uh that we used to clean the condenser of a refrigeration system with refrigerant from the refrigerant can they all like oh how could you do this I mean everybody was doing it because all the spray cans hairspray deodorant everything used CFCs as a propellant so this this was normal until the 1970s and actually the US was the first country in the world uh to uh say that you could not use CFCs anymore in in spray canes in in 1976 so uh those synthetic refrigerants they brought us the ozone hole they brought us global warming and now the new fluids hfos they even bring us uh to destroy all the the water the fresh water sources we have so it’s uh yeah you can see that refrigerants they conquered the world from the stratosphere to the to the soil to the ground um and this is for sure not sustainable um and here just two slides I think on this hfo uh thing because these new fluids they are designed to break down in the atmosphere very quickly um and they form something called Tri fluidic acid and this TFA may have an influence on the fertility of uh animals and thereby also on on humans and there’s an increasing amount of TFA in all the freshwater sources coming from uh the refrigerant and you can see here this is a comparison from the 1990s 1995 to today uh it’s a factor of 3 to five higher in the Ryan River you can the Ryan river is very close by you can see here how the concentration is increasing in the Ryan River yeah from 0.4 microgram to 1.4 microgram in dlor when it exits Germany this is an a simulation from British scientists they say all the 134 for the old H ofc refrigerant emitted to the atmosphere today converted into or or replaced by this hfo fluid 1234 YF and emitted at the same location the difference is 134a only has 20% TFA formed in the atmosphere this 1234a YF forms 100% TFA so it’s five times more the other difference is that uh 134a has an atmospheric lifetime of 8 years so what whatever you blow into the atmosphere here in K Ru will break down in South Africa in Australia in Antarctica somewhere on the globe but not here because it’s first in 8 years 1234 YF breaks down within 2 days so if there’s a day without wind whatever you emit here from a from a car air conditioner will break down right here or stutgart is even worse because you have this Valley and there are 800,000 cars in stutgart and they all emit this 1234 YF that’s why we get this uh yellow and and orange spot right in our area here so the prediction is that we give 250 Times Higher TFA concentration 250 times more and all this will end up in Lake Constance yeah bordy or in in any other thing in Lake constant the water from Lake constant is used as drinking water in in stutgart and there will be in a couple of years that they cannot drink it anymore very nice because of that there’s the the this um proposal from five European countries to the EU to Outlaw not only TFA but all different kinds of peers all these forever chemicals and there’s a similar announcement from California and there are also things going on even in China on on this uh uh topic so we will see what happens this is my own personal view on on those hfo refrigerants I mean some of you may need a pocket calculator for calculating this uh but this is the wrong way I mean it’s the wrong way to use a pocket calculator for an easy thing like this uh but our daughter does uh but the other thing is this is not the calculation what I mean with this is it took 60 years to figure out that the CFC is damaged the ozone layer and then the replacement fluids the hfc’s they contribute to global warming and that took 30 years and uh I say that it will take about 15 years to get rid of the hfos again and the first time I showed this slide is now 7 years ago so there maximum 8 years left for the companies manufacturing these chemicals luckily there are alternatives we can have CO2 we can have ammonia we can have propane or isobutane as you have have in your refrigerator at home there you can actually check there are small name plates where you can see what the charge is how much isotine is in your refrigerator any idea how much it this approximately so we said 2.3 G in in a lighter 180 g in in the hairspray can so in the fridge small fridge 25 30 G the larger ones maybe 70 80 G and the limit is at 150 because they 30 years ago said the typical kitchen has this size and the maximum isobutane level you want in your kitchen is 8 G per cubic meter and then they came up with 150 g so if you have a smaller kitchen and you leak the refrigerant you may have a problem if you have a larger one then you never have a problem and of course you can also use water as a refrigerant um perfectly well I will show you an examp sample from Denmark uh on the heat pump running on water this is a heat pump running on co2 and we have a similar system in our lab so all the students from um mechanical engineering or mechatronics they they test they they can try this equipment this installation was at Mena in in Z in the in the University of applied science and you can see there the bottom line is payback return on investment payback time 1.8 years so it’s actually very beneficial to use a heat pump and the nice thing with with CO2 is that you operate uh in a so-called transcritical cycle so in the pH diagram here’s the critical point and then you are above the critical point and you have a lot of energy you can take out of the CO2 that’s why CO2 is very good for heating water actually the largest CO2 heat pump in the world is right now installed in espak in in Denmark uh it will supply the entire District heating system with heat from the North Sea so they take the water from the North Sea and then Pump It Up with the CO2 heat pump uh to supply all the houses in espak with heat and if you’re interested in that you can uh listen to the presentation on the 7th of November uh there will be someone coming uh from Norway who is uh yeah kind of on on the project team he will present the seat pump at our energy for you this is another heat pump uh you will be able to see at this energy for you or you could see it tomorrow during our heat pump Symposium this was invented by two students mechanical engineering students they came to me one day and they said oh Michael we had the crazy idea yesterday when drinking beer and I said oh what’s what what what idea was it and they said oh we want to build a vice wor Verma pum a sausage heat pump I said okay what is the sausage heat pump and he said oh you have to heat the sausages and you have to cool the beer so we take the heat from the beer and put it into the sausages and I said this is not a crazy idea it’s a brilliant idea go ahead and build this thing so they built this thing and then they made some measurements you can see there takes about 45 minutes to cool 30 bottles of beer and to heat 80 sausages and what they found out when they made made this self test is uh at a certain point the average student is no longer hungry but still thirsty uh so they put in an air cooled condenser so this thing can always cool beer but doesn’t have to heat sausages it’s a nice thing we used that we were last week in in frankurt at the arima with this thing you can see down there 3 385 G of isobutane um so it’s well below the 500 G limit which is now for commercial applications and the nice thing is you can only do this with isobutane we have an evaporation temperature of min-2 and condensation temperature of plus 95 it’s not possible with any other refrigerant in a single stage process and this was the yeah when they had their final presentation um of course they got the highest grade then you could say okay isobu is flammable um what about that um there were some tests done on air source heat pumps if they leak and you can see there I mean is a little little flame but it will not blow up uh the house and it will never kill any people um and there’s this at the bottom line there it says a study from Switzerland from 1999 uh it’s 100 times less risky than having a gas furnace and a gas furnace is well accepted this is this Swiss study from 1999 and you can see here on on the left hand side it’s how many dead people you have per year and how many um injured people you have per year and uh I mean it’s it’s a little bit of course for the guy installing everything but for the for the homeowner nothing uh and here I mean the scale here the scale on the left side and the scale on the right side is different so you have the the home owner and then the home owner with the gas furnace and driving with a car so it’s perfectly uh safe to have propane in the heat pump if you do have some doubts then you could go to water it’s the perfect refrigerant because it’s not flammable it’s not poisonous but if you look on a worldwide basis there are more people dying because of water in their lungs then people dying with ammonia in their lungs or with a house exploding due to propane so actually water uh can also be very um dangerous and there are some companies listed there who are working with water as refrigerant and the one I want to show you is this one it’s my my former colleagues I used to work in Denmark it’s also why I can speak Danish unfortunately not fluent Swedish but we can get along and tonight when we will sit in the in the restaurant and after the third beer then B and I can talk a fellow Scandinavian language uh this is a heat pump installed in orus also for district heating system they use water as a refrigerant and also the heat source is water they use the water from the harbor and the first stage is water vapor compression heat pump and the second stage is an ammonia heat pump and you can go there it’s like an open Museum if you ever make it to Denmark into orus go down to the harbor it says on the on the outside musin H it you can go inside and have a look um and see how how the system is working and there yeah you see the the gray part is the water uh heat pump and the green part is the ammonia now just a few ones but maybe beond because I think you have in your presentation nicer pictures and and better explanations uh this is an air source heat pump which you probably have seen and this is yeah if you look there this is the way they some of them look like you shouldn’t do that uh if you have a neighbor here because then that neighbor will say that this thing is noisy but if you place it somewhere where he cannot see it then it’s fine this is ground Source heat pump like this pattern from 1912 uh he had the refrigerant in in the ground and typically you have in the ground a water glycol mixture in Germany in Sweden it’s water ethanol because the water ethanol is is better from a thermodynamic point of view but of course some people drink the water ethanol even though it’s denaturated and that was a case um um OK Oka Melinda told me once they had a case in in in Sweden in in a hospital with this ground Source heat pump running on water ethanol that they had a leak and they couldn’t find the leak until they figured out that there was a small uh tap for taking a sample and this this step uh for taking the sample was in the in the department for the alcoholics and they were they were actually drinking it and this is a the typical ground sour seat pump where we have ground probes in the earth and we had here at our University a nice project some years ago we developed a measuring system it’s a very small ball or sphere which can float through this ground probe and take the exact temperature uh distribution throughout the ground this is something uh yeah you can also do it’s uh like you have one Central uh heat pump making the first step and then you distribute the heat in a in a ground network but at a temperature of maybe 15 to 20 degre not 70 like a district heating system so the heat losses in the ground are smaller and then in each individual house you have a small heat pump the way they do this in in fish and in in BL is with a with an ice storage seasonal ice storage and they freeze the ice it’s called ice on coil so they have some plastic piping inside a very big vessel filled with water the plastic pipes run a water glycol mixture inside and this water glycol mixture is then going to the heat pump to the evaporator as the heat source for the heat pump so you have several like heat exchangers uh the efficiency is not very good uh and we had a European project until last year two years ago U with I think something like 10 Partners where we improved this system yeah we removed all the plastic pipes in the in the storage vessel and just had the operator of the heat pump uh itself produce super cooled water you may have experienced super cooled water yourself take a plastic bottle place it in the freezer and uh cool it down to-4 – 6 and it’s not frozen and then you open the lid and the CO2 initiate initiates the the the freezing process the crystallization process that’s exactly what we did in this European project so we cooled the water down below the freezing point and then afterwards we had the crystallization and we could in increase the evaporation temperature by 10° and 10° increase in evaporation temperature means 20 to 30% energy increase as compared to this system last type which I will present is this one um you can of course also use the exhaust air um from from your building for example to heat hot water in in a heat pump and then oh I’m sorry there was one more this is a groundw water heat pump so you can take water from the ground and pump it back that’s what they do here in C at the at the hospital and in in rosville and uh at the lake of syk where I live they use it for the zoo for the elephants to eat the elephant house and then the future uh and that’s something Sebastian and I have talked talked a lot about are these pvt collectors this is a a PV collector making the solar energy into electricity at at the same time also producing heat so you get the electricity to run your heat pump and you can take the heat from those pvt collectors as a heat source for the heat pump and then those systems are very efficient and there is at least one company already doing this uh in Switzerland in in syc um but maybe we can still make a research project out of this and maybe beond you have it in in Sweden as well even though the sun is not shining that much in in Sweden as compared to here uh and then the other other source energy source you can use for heat pumps uh is all the heat from the refrigeration systems when you drive here from the University towards anfang you have this like commercial area uh there’s a large Tire manufacturing like a plant from a French uh tire manufacturer they have to cool all their equipment so they have a refrigeration system which has something like 1.5 megawatt Refrigeration capacity now the coefficient of performance of that system is not five it’s May maybe more or less like three um yeah but that means that they blow yeah some 2 megawatt of heat into the air in K and at the same time there 39 uh other companies surrounding they all all need some Heating and the easiest thing you could do is just put a heat pump on top of this refrigeration system and Andrea we had this some years ago as a as a study I don’t know what happened if they if if they installed it um but I know that they did in um in V Bron there’s a an ice skating arena very nice design uh ammonia is refrigerant next to it is a is an open air uh swimming pool and they said okay we take all the heat from the from the ammonia system and put it into the swimming pool the little thing they forgot is that the swimming pool is open from May to September and the ice skating ring from October to March yeah uh I was there once with students in January and it was the pool was packed but not with people with birds yeah they had 25° warm water and there was snow surrounding them and then I said I mean how stupid can you be on the other side of the street there are there are a lot of uh companies just get a pipe from here to there and heat all those buildings and that’s what they’re doing now so this this this was installed so this is the conclusion uh heat pumps are the heating system for the future what Bon also tried to tell you and um yeah I think we still have maybe quickly go through your side slides or the last ones in case you want to know something about natural refrigerants there’s a a nice book uh about natural refrigerants and there’s tomorrow afternoon a whole conference on heat pumps in Stein by’s building unfortunately all the the seats are taken there there’s no more space for come for coming their life but you can follow on YouTube If you go on the on our homepage the hro homepage There’s the link for the two you YouTube things B will also present again I will present something and then the other thing where you can go live uh if you are fast enough with the registration is the 7th of November this energy for you where we also will have a lot of things on heat pumps and in case you as as the students if you are in c r in September we have one week uh sustainability summer school you will get free uh ects free credit points um it’s a full week program starting one morning at 8:00 and finishing Friday evening at 600 or 7 um it’s only 100 to participate we have space for 40 students we will have a lot of interesting uh exercises and excursions technical visits uh and we will also have a lot of fun so now you questions take some questions I I think we still have half an hour oh half an hour I mean if you have questions for half an hour we can stop here or otherwise beond can take 10 minutes more um Now give me 10 minutes thank you so um as you may notice there will be some overlap in between the presentations but I hope you don’t mind so we talked about uh different types of heat pumps uh have some more slides about that and I can add some things I mean um it is sometimes claim that energy or we should use electricity in some other way than for heating that was the old way of thinking I would say but now as all the energy will be supplied in the form of electricity we will definitely be using uh electricity also for heating but one problem with Renewables is of course that it’s not a steady source of energy so sometimes it’s windy sometimes it’s sunny sometimes it’s nether windy or sunny and the price of electricity will go up and down and uh our response to this then is that to say that heat pumps can actually be used to even out these uh variations in availability in electricity and Avail and the electricity price and now nowadays everything is connected anyhow and controlled in different ways so it would be relatively easy and that is already done in some places to to control the heat pumps so that you run them as much as you can when it’s uh when they’re electricity is cheap and uh when it’s uh the electricity is expensive you avoid running it so this is just showing some graphs of of availability of the energy price and um the availability of energy and how you could sort of say shift the loads from hours of high peaks to hours of low Peaks and this could be done with a heat pump done uh where you also include a storage so even though the house is warm you can still run the heat pump and U in this case it’s a uh phase change material here so you different basically allow a a wax to to melt during U the the nighttime for example when electricity is at low cost so that is one way to to use heat pumps as a part of a an intelligent Energy System we already talked about decreasing the charge and this is some uh ex examples from our lab we also did a heat pump with I isobutane working with 120 g and 12 kilowatt in capacity so it’s comparable to what they now have done also in frover and um yeah there is a lot of interesting development here both on the compressor side and on the heat exchanger side to to reach this because previously it has not been important to have low charges because the the refrigerants were not considered to be dangerous in any way they were not flammable not not poisonous so there was no pressure to try to decrease the charge but nowadays we because of the flammability and also I would say because of the effects on the environment we try to reduce the charge and this has had a big effect if you compare different heat pumps you will see that some large use a large Capac charge for a small capacity and others use a small charge for for large capacity um yeah so how will we solve this problem with the gas heaters it’s is this what we will see in the future that could be a question right I don’t think anyone would like to see cities like this and there is research going on on this also how how should we manage this and this is just a picture taken from uh the LCR 2090 project which are they’re running in frown Hofer and you can see that there are different options here uh you could have sort of one heat pump for each level or you could have one heat pump in the basement and then have uh water sent around in the building or you could you could place the heat pump outside and then uh heat heat the building and of course another solution would be to have District he and District heating is not an energy source as some people seem to believe and District heating is a way to transfer energy right so you need still need some way to heat the the water in the district heating pipes and that should of course be heat pumps um so just to continue this is University of Stockholm where we’re using heat pumps and we were involved in the project where we uh made a large number of bore holes 13 B holes 230 M deep so these B holes can be used for dumping heat during the summer when it’s hot and for extracting heat during the winter when it’s cold so the ground is sort of an energy storage in this way and another slide showing a similar solution this is a place where there is lot of lots of gravel in the ground gravel with water so basically we have two two Wells one cold well and one hot well and during the summer we can dump the Heat in the one side and then during the W this the winter time we can sort of say Force the water the other way but you would still need of course a heat pump here to to allow this to work because the temperatures down or the water down here is is far from the temperates we need for for heating um what else was there yeah I mean heat comes be used in a lot of different applications we you may not be aware of it but Electric cars need to be heated and there is no waste heat from the engine there so so they actually have a heat pump already now both reversible heat pump which can be used them for both Heating in the winter and for cooling in the summer and when you buy a new dishwasher or a new tumble dryer you have the option to buy a unit including a heat pump so U so heat pumps are there already in some products and I’m sure that we will see more of this in the future um finally something on District heating um this is showing the energy input for district Heating in stock from 1970 to 2017 so uh Back in 1970 we used almost entirely oil and then you can see how the biofuels have taken over more and more so there is very little fossil fuels now in the district heating production and you can see also that um on the top here uh the green and the purple on the top that’s actually uh waste heat from this city waste and also heat pump heat heat from heat pumps and of course this can be as Michael also said used to much larger extent in the future because I don’t think it will be possible to use so much biofuels in the future the biofuels will be so expensive that we cannot use it for just for district heating that’s my belief uh this was just a uh picture showing uh what the heat pump looks like in that case and Stockholm is a city of water so there is a lot of water to take heat from so uh here you can see another heat pump which is located uh on a pier here and the water is taking from the center of this Bay and uh from the in the winter the water is taken from the bottom and the temperature is about 4° and in the summer uh The Temper the water is taken from the surface closer to the surface where the temperature could be up to 20° um and yeah so it’s a lot of water of course needed if you just have four four degrees to sort of decrease the temperature from if you during the winter time so standing at the at this pier it looks like standing at the back of a big ship there is a lot of water coming out from the uh heat pump there yeah I just want to mention that it’s it’s not only I who think that or Michael who think it’s important with u heat pumps for district heating IA also has included in their report the future of heat pumps uh some text on this that that decarbon decarbonization potential of District heating is largely untapped at present which with fossil fuels still supplying around 90% of this of District heating globally so Stockholm is an exception here you saw we used to use a lot of bofes but in other countries is mainly fossil so between 2030 and 240 Denmark is set to provide nearly a third of the district heat Supply with heat pumps four European countries Austria Denmark Finland and Sweden currently have tges to decarbonize District heating networks to 2030 so um that is the goal of these countries and when we talk about this heating traditionally this is like water of temperatures of 80° or so or perhaps 100° or even 120° but you could also build other types of smart grids where the temperature in the circulating water is much cooler so cool that it could be used both for heating and cooling and this is what is shown in this this sketch here which is actually an installation in Switzerland so in some buildings they need Heating and then they use the loop here as a heat source and in some buildings they need Cooling and then they use the loop to dump the Heat and of course in each of the buildings they need either a refrigeration system or a heat pump or both or a combination so um and this this is discussed a lot U it’s sometimes called fifth generation District heating but with fifth generation District heating you will have so low temperatures that you will need a heat pump in each building that is one conclusion and just to explain this in a little bit more I mean of course uh this Loop during the winter time will tend to cool down when everyone needs heating so then the loop is connected to B holes in the ground which is basically used as a heat storage so during the summer the warm water which is coming from the air conditioning all the buildings cooling of the buildings will be pumped down in this Bo four holes and then during the winter the water is pumped the other way the the heated up ground will be used as a heat source so and there are other installation this is from Sweden it’s do it’s a similar type of installation so just finally how something about industrial heating it is actually also possible to use to heat pumps for higher temperatures we didn’t talk about the how to calculate the efficiency of a heat pump but basically it’s it’s very important to to have as low temperature differences as possible and I think Michael told you that in one of the slides when we talked about this re redoing the ice machine but U so if you want to reach let’s say 300° or so the efficiency would be rather low but uh 150° would be possible and perhaps even 200 and if you compare it to direct electric heating it will always be a little bit a bit more uh efficient but the higher temperatures you try to reach if you have a low temperature Source then the efficiency will be go going down but there are this this type of machines already available so here you can see on the horizontal axis you have heating capacity so it’s and this is basically different man manufacturers or compressor manua factors and on the vertical axis you can see the temperature levels which can be reached so there are already products being able to produce hot water at 150° or 160° even for so it can be used heat pumps can be used also for industrial applications where you need higher temperatures than is usually needed for heating of buildings so that was basically my last uh slide but my conclusions once again global warming requires face out of fossil fuels I think most of us agreed to that renewable energy and nuclear energy produce electricity so heating will in the future be based on electricity and according to political decisions the number of heat pumps in Europe will increase and this factor six or seven different sources tells us different but there will be a almost exponential increase that I’m sure about that heat plants will be used wherever heating is needed from home appliances to District Heating and Industry so I I think that was yeah the larger increase and the simultaneous phas out of f gas will require a transition to natural and flammable refrigerants so with that I think thank you for your attention I’ll leave this up thank you very much Bon very interesting we will learn tomorrow there are some some more presentations from Scandinavia this uh Swedish heat pump manufacturer they will present and then we will also look at what the difference is yeah why heat pumps are so so popular in in the Scandinavian countries as compared to to Germany uh and it can’t be the temperature because it’s colder in Norway and in Sweden so it’s uh should be even more attractive to do it in Germany but maybe maybe they have better politicians in uh Scandinavia okay questions thank you very much to both of you yeah and now we have time for questions you can um so you were presenting that they use the water from the harbor to uh yeah for the heat pump um what effects does it have for the environment when you put in the cold water or the warm water um back into the uh Harbor as far as I know we have See No Effects I mean compared to the amount of water passing through this Bay the the amount which is well the temperature change of the water in general is so small that it doesn’t have an effect so if if you heat enough buildings with the heat pumps you may be able to get the Penguins in in the scare yeah yeah we we have a similar case actually with a nuclear power plant some 150 km north of Stockholm where all the cooling water is into a bay and there you have a definite increase in the temperature so some of the birds they love this place because of the high warm water but that is made on purpose of the satas yeah how do you see the future um relevance of the pvt technology well I think they have a bright future we just have to uh work on the manufacturing to to make them cheaper because the the the the pure PV element you get from China nowadays is very cheap and these pvt elements they’re manufactured somewhere in in in Europe and right now the price is uh a lot higher than than for a normal PV module uh so we have to work on bringing that down and also look at what is used as the heat transfer medium uh should it be air or should it be water or water glycol mixture or should it be refrigerant if we evaporate refrigerant um and then next question is how how do you set it up like if you do it with water glycol then you have some connections which you have to make on the roof which should be tied for yeah for decades so yeah there’s some still some development there but it’s it’s the good thing is like the the PV element is more efficient the lower the temperature so if you cool actively cool it from down below and with with a heat pump you could cool it below the ambient temperature uh then you get the high efficiency of your your that’s something for thank you other questions maybe I can add one from the live chat we have from the internet there is a question about a new or alternative technology for heat pump uh the electrocaloric way if is if I got that right Rina electrocaloric heat pumps where you don’t need any refrigerants what does it say yeah I mean of course there are different other Cycles which can be used for heat pumping I guess this what yeah yeah yeah yeah yeah yeah Electro electral yeah so alter alternative fluid we call it in the in the unep RTO we call it not in kind technology I actually gave a presentation on that in September last year and we have a colleague at kit Campus North she her PhD feis was on that and she’s has a whole group working on that but and she also participated in this presentation last year in September and uh there are some nice Technologies but the conclusion is like right now uh they all not competitive with the vapor compression cycle this doesn’t mean that they will never B uh because if you just look look at your watch uh I don’t know if there’s anyone in the room who still has a mechanical uh watch most of them work with quartz technology the same with the light bulbs if you think just 20 years back uh it was all Edison Light Bulbs nowadays everything is Led um maybe I don’t know maybe we will see something similar in heat technology but right now it’s not on the horizon there there are some some things worked on on like the research stage but there’s nothing which is uh able to be put into a house anywhere I could add to that I mean we had a PhD student who actually worked for Electrolux they manufactur refrigerators right so they wanted to know if this was magnetocaloric was a good solution for the future because there was a lot of discussions about this and a lot of hope that’s about five six six seven years ago and uh I mean our investigations showed that it was we we would we were very far from from getting the same efficiencies as we would get with our ordinary Vapor compression cycles and and I think there is one one reason one reason which is common to all of these alternative Cycles when you have a vapor compression cycle the the temperature change is in the fluid itself you compress it and then the temperature increases and then uh you can allow this fluid to to give its heat to the ambient or to to heat exchanger but if you have these other cycles and you usually have a material which heats up and then you have to transfer the heat from this heated up material to some other place where you should then dispose it so all of them have the this problem that compared to the vapor compression cycle where the fluid itself changes temperature you have to have another fluid which is should be heated up and cool down and transfer to another place and give off heat so I think that is one reason why it’s difficult to find alternative Cycles but it be comes down to materials technology I would say we need better uh materials which change more in temperature when you apply the electric field or magnetic field or uh Force tension on these materials and so it’s it’s it’s not a mechanical engineering problem anymore it’s it’s it’s a material technology problem like when when I I studied mechanical engineering at the University of of Hanover in the north part of Germany and had my thermodynamics lecture with a person called Professor be H be and that was in 1985 and uh he said because also in Hanover you could choose different subjects uh and one of the subjects was of course refrigeration and the other ones was design engineer and then production engineer and uh this professor be 1985 said you can choose any specialization within mechanical engineering you want but don’t choose Refrigeration everything is invented everything is known there’s nothing new but what he forgot was the ozone crisis ozone hole uh global warming yeah and I can tell you that like I started working with refrigeration outside the university 1986 when I went for a year to as a guest scientist to to the US to work at the national Institute of Standards and technology so I have almost 40 years of experience and it has never been boring and there have always been new things so this professor thermodynamics Professor was completely wrong when he said that everything is invented and nothing is new yeah just to add one more comment to that um they say that Einstein when he wanted to relax he invited his friends and then we they tried to invent a new cycle for producing cooling so that was something they did in the Saturdays and Sundays perhaps new cooling Cycles okay maybe one last question from my point of view is there any reason or let’s talk about in the future is there any reason that a heat pump or in C in terms of taking about talking about the costs that I have to pay for a heat pump nowadays the costs are especially in Germany quite High because I think think about to the subsidary subsidiaries we we we get yeah is there any reason that the heat pump is more expensive than a gas boiler or how much in terms of factor can you can you propose something right now what is it three three yeah but it’s three five times higher price than for for a gas boiler three to five times more than a gas boiler I think it is more a little bit more complex yeah you have to have a a compressor and a fluid um it’s it’s easier to have a just to get a gas from out of somewhere and to boil it to burn it but what do you think I mean one one of the reasons is the the number of units manufactured and uh how automated they have everything and you can get I mean the the typical heat pump capacity for for a single family house is uh yeah if it’s if it’s an existing house maybe maybe 12 14 kilowatt heating Capac capity if it’s a new built house then you you can get away with four or 5 Kow because they’re better insulated and and a heat pump like that I I didn’t check the prices now but what was that 10 years ago I checked because I tried to replace my my oil burner with with a heat pump and uh the two challenges were the same what you say with the price yeah I could get gas furnace fully installed everything for was almost around 14 14,000 like taking the old oil out uh and doing something on the on the on the hydronic system and then putting this gas furnace in was 14,000 uh the then and I tried to get uh something some offer on on a heat pump um which I I couldn’t get because they all all refused they said no this is an old building and we will not do it and your oil furnace has 50 Kow you need the heat pump at least with 25 Kow and I said no I don’t I I made some insulation uh 12 or 14 Kow is enough uh but if if I had ordered a heat pump in German heat pump manufactured in Germany at that time as a private person ordered somewhere on the internet I would have had to pay something like 11,000 12,000 uh and as I said I didn’t get get any uh heating company to to make an offer on on the heat pump because they all thought that it’s not possible on an ex existing house which is which is stupid it’s not true yeah yeah you can place a heat pump in an existing house you could even do it with 25 KW uh the the the top of the line was someone who said okay you can get your heat pump but you need one with a ground source and then I got an offer for the ground source for drilling holes in the ground and putting these probes in there uh €5,000 back then nowadays it’s probably 50,000 uh and and the the very stupid thing from this company was like okay you have to pay those 25,000 uh but whatever we hit in the ground is your own mistake you have to repair it and I said forget it because this is this house has been here for 50 years I don’t know what is in the ground and where there are the cables and where there are the the the drain drainage pipes if you damage anything then then it’s it’s another couple of thousand Euro so I ended up ordering this gas furnace for 14,000 and when this when this person came he was like oh you’re Michael coffin you’re working with heat pumps why did why didn’t you order a heat pump I said yes I want it but no one offered it or we could do it and then said okay now it’s too late I I already paid for the gas to come in so we we will not do it so this house has a gas furnace now okay yeah just to add to that I mean I totally agree that it’s a a matter of scale I mean you if you go out and buy a an air conditioning system a small air conditioning system split it’s doesn’t cost very much and you I mean the these are produced in many many millions in in nature right so the when we start producing the type of heat pumps we need in Europe at the same numbers then the prices will be going go down quite a lot I would say the typical split air conditioning system is anywhere between one and a half and 2 and a half thousand Euro and and you can also get them now with propane as refrigerant but not from European manufacturers yet uh but from Chinese and Indian uh manufacturers okay thank you very much thank you to the audience for the discussion and yeah enjoy the afternoon the evening see you next week bye-bye e e e e e e e