High temperature heat-pumps: a sustainable and efficient solution through industrial decarbonisation

High temperature heat-pumps: a sustainable and efficient solution through industrial decarbonisation

Decarbonisation of the industrial sector is currently is at the heart of the European agenda, as it seeks to reduce greenhouse gas emissions and achieve agreed climate targets. The European Union aims to be climate neutral by 2050; that is to say, it has set itself the goal of having an economy with zero net greenhouse gas emissions. According to Eurostat, the industrial sector accounts for approximately 20% of total greenhouse gas emissions in Europe. Action in this area is therefore crucial in the fight against climate change.

An increase in the energy efficiency of industry in Europe is essential to reach the climate targets mentioned above and one effective way to address this is the utilisation and revalorisation of waste heat produced in industrial processes. This can be achieved through high-temperature heat pumps, which operate without electricity consumption and use waste heat to produce energy-intensive thermal energy and for industrial processes. The integration of these technologies could potentially cover 15.3% of the thermal demand of industrial processes. To learn more about heat pumps I invite you to visit the following article on our blog where you will find a very encouraging perspective on these technologies.

Furthermore, the potential integration of renewable energies is essential for change and these technologies can work in a complementary way with renewable energy sources such as solar thermal energy.

CARTIF is part of the PUSH2HEAT project consortium, a research and development project in the field of industrial decarbonisation. It´s a project funded through the Horizon Europe research and innovation programme that aims to overcome the barriers to the deployment of high temperature heat pump technologies for a better use of heat in the industrial sector. The market for such technologies is currently limited, but with the creation and implementstion of appropiate exploitation roadmaps and business models, very promising figures can be achieved on the road to emission reductions in the energy sector. Based on an estimated annual process heat demand of 298TWh between 90 and 160ºC that could potentially be covered by heat pump technologies and assuming a COP of 4 for the heat pump, 45Mt of CO2eq emissions could be avoided by switching from gas boilers to these electrically driven technologies. This corresponds to approximately 8.3% of the overall UE27 greenhouse gas emission reduction target from 2020 to 20230.

PUSH2HEAT, with a duration of 48 months, will bring together experts from different fields to drive the market and address existing technical, economic and regulatory barriers to waste heat recovery through large scale demonstration of heat-enhancing technologies in various industrial contexts with supply temperatures between 90 and 160ºC.

CARTIF is delighted to work with a consortium that is motivated to achieve satisfactory results to the challenges posed in the project and to continue with the necessary energy transition for a more sustainable future at the industrial sector.

If you want to keep up to date with the process, stay tuned for the results!

Is all that glitters gold? (When talking about heat pumps)

Is all that glitters gold? (When talking about heat pumps)

“Pumps, pumps…” So goes one of the best-known songs by a Spanish artist from the early and mid-90s Spanish music scene. Although too much has happened since then, we can relate the theme to the current energy crisis we are suffering, caused by the war between Ukraine and Russia.

We are talking about heat pumps.

The concept of how heat pumps works is very simple, in fact, we all have a very similar, refrigeration machine at home, the refrigerator. Heat pumps, like the fridge, base their operation on compressing a refrigerant liquid contained in a closed circuit. This liquid is capable of collecting heat from the environment (in the case of the fridges, it collects heat from inside the fridge, cooling it) and thanks to the compression it undergoes, its temperature increases. This heat is then dissipated in the grille at the back.

The same applies to heat pumps, which are able to collect heat from the outside (even if the temperature is low) and thanks to the compression of the refrgierant, increases its temperature, thus making indoor heating possible.

Because heat pumps are highly efficient equipment, they don´t help to reduce the energy bill of our homes.

Im sure you have heard oft aero-thermal heating, right? Well, if you have any doubts about what it consists of, it is based on the operation of a heat pump that collects heat from the air in the outside environment (hence its name).

It is well known and proven that more than 40% of the energy consumed in Europe is used to air-condition homes. In this sense, heat pumps are the perfect ally as they offer us an efficiency of around 400%, that is to say, for every unit of energy they use, which is usually electrical energy, they are capable of producing 4 units of thermal energy (both heating and cooling), thus offering us high savings rates. In addition, new technologies nowadays allow us to reach higher and higehr heating temperatures due to the use of new coolants and new technologies, such as heat pumps based on acoustic waves that replace the electrical energy source with ultrasound to excite the coolant and thus increase its temperature, but…

Is all that glitters gold? Let´s take a look at it; actually when talking about savings from the use of heat pumps, we have to talk about energy savings and then..we look at the money. Calculating the economic savings provided by theseenergy savings is extremely complicated in the times in which we live, let me explain; currently the price of electricity (the most common energy source for heat pumps) is on a constant roller coaster, where you can see every day how the price changes considerably between the valley-flat-peak periods, in addition to the difference in the intra-daily price (nobody really knows why, there could be many explanations that would take several entries in this blog).


In addition to the price, the different energy sources have to be taken into account, as it is not the same thing to replace a gas or oil boiler, electric heaters or any other heating source with a heat pump. This makes it more difficult to talk about economic savings because the different energy sources also come into play

A third derivative in the economic sense, and something that heat pumps manufacturers do not usually take into account, is that in the case of installation in a home, this is not normally prepared to cover the new electricity consumption that is going to be produced by the installation of the pump, and I will explain this with an example:

Let´s imagine we have a 37kW gas boiler of supplying heat to a house and we want to replace this boiler with a heat pump. We have already mentioned that this equipment offers a ratio of 4 to 1 in terms of heat production and electricity consumption, therefore, to cover 37kW of heat, we have to consume 37/4 =9.25kW of electrical power which we will probably not have contracted and contracting them will increase the bill we are going to pay every month in terms of the fixed term, whether we use the heat pump or not. 

So we are saving or not? The ideal way to estimate the savings from installing or replacing an old boiler with a heat pump should be done implementing a reliable measurement and verification protocol, as has been done in the REUSEHEAT project in which CARTIF has participated in the implementation of the IPMVP. To this end, monitored data from the heat generation systems of several demonstratos have been used, connected to the internet via different IoT protocols, send this data to a common platform where the energy savings are calculated.

This savings are calculated on the basis of a mathematical model made with the data from the time period before the installation of the heat pump. Once the actual consumption after the installation of the heat pump is known, the conditions under which this consumption was achieved (weather, indoor comfort,etc.) are taken into the model and the energy that would have been consumed under the conditions prior to the installation of the heat pump is calculated.

At this point, knowing the energy that has been saved, the moneysaved by using heat pumps could be estimated economically, on the basis of an average price, a more detailed estimate of the price, or as you think best.

Savings obtained at the REUSEHEAT project in one of the demonstrators (comparison real consume vs model at the superior part and savings obtained in the inferior part representd by bars)

The REUSEHEAT project shows very satisfactory results for the use of this type of technology and the energy saving produced. In addition, heat pumps are considered a renewable energy source (when in addition to using aero-thermal energy they meet certain conditions) and clean and avoid a large percentage of CO2 emissions. There is talk that they could reduce greenhouse gas emissions by 70%.

CARTIF believes that we ,ust continue to support this type of technology and the innovations that help us to improve them, not only for heat pumps based on aero-thermal energy, but also geo-thermal energy, hydro-thermal energy,etc.

We say goodbye to mySMARTLife

We say goodbye to mySMARTLife

The closing process of a successful project, executed for 7 years continuously (60 months of implementation and almost a year of preparation), always carries a bittersweet feeling.

On the one hand, there is the satisfaction of having achieved the objective, which is none other than reaching the major energy and environmental impacts committed to. On the other hand, in the case of mySMARTLife, where the main beneficiaries are the citizens, this feeling of satisfaction is even greater. But it is also true that there is a certain feeling of melancholy, especially related to the foreseeable lack of contact with the many people from organisations in different countries who have accompanied you throughout this process. It is something like being relieved, happy and satisfied, but at the same time a little sad at having to say goodbye to colleagues and friends with whom it will not be so easy to keep in touch due to the distance. Something difficult to explain, but I’m sure many of you who read this blog have experienced it at some point.

mySMARTLife leaflet

After a few days in which CARTIF has managed to recover from the tremendous effort required to close our mySMARTLife project, as the famous song by Mecano (so appropriate for these dates) says, it is time to take stock of the good and the bad.

mySMARTLife was a project that involved three cities of the size of Nantes in France, Hamburg in Germany and Helsinki in Finland, surrounded by strong innovation ecosystems, which committed to improve energy efficiency by 55% in three districts and to cover the remaining energy demand with at least 54% from renewable energy sources. In addition, they also committed to a massive deployment of electro-mobility actions and to improve and strengthen existing data acquisition and decision-making platforms in the three cities. To this end, the project undertook to design, implement and evaluate 140 actions, which have already been successfully implemented and have leveraged more than 200 million euros of investment, receiving close to 18 million euros of funding from the European Commission under the Horizon 2020 programme.

CARTIF congratulates itself for having fulfilled this ambitious commitment. The numbers, which are usually cold, in this case allow us to certify the resounding success of the project.

147,054 m2 of heated space have been rehabilitated or built under high energy efficiency criteria. 8,777.59 MWh of net energy have been saved per year in the three districts by the energy efficiency actions deployed and 4,350 electric vehicles have been deployed in the three cities (including 388 electric buses). In short, 33,145 tonnes of CO2 are not emitted annually into the atmosphere in the three cities as a whole. In the local vernacular, that’s a great deal…

This overwhelming success is further complemented by the three energy transition plans in the follower cities, which are already underway, starting the implementation phase of the actions studied in many cases. Such as the district heating in Palencia, the city closest to us, which is already in its implementation phase. As said before, the numbers in this case do reflect the achievements of the 6 cities accompanied by the rest of the project partners.

Before closing mySMARTLife, I would like to mention or highlight some of the most emblematic or innovative actions. In Helsinki, a 3D Energy Atlas was developed to help plan solar actions throughout the city. In Hamburg, hydrogen (H2) was injected into a gas network. For several days, up to 40% hydrogen was injected into the grid. In Nantes, 22 electric buses with a length of 24 metres and a capacity of 150 passengers were designed and deployed. In Hamburg, in addition to deploying 80 electric buses, a complete electrification of a bus depot station for recharging, mainly at night, was carried out. Finally, two electric mini-buses were piloted for the first time in France or Finland under autonomous driving in real traffic conditions. These are just a few examples of the actions deployed by mySMARTLife.


But as in CARTIF we do not take even a minute of rest, we are ready to start new adventures. On the 31st of January, 1st and 2nd of February we start NEUTRALPATH, a project around the theme of Positive Energy Clean Districts, in which we will work with the cities of Zaragoza, Dresden, Istanbul, Vantaa and Ghent. But this will be the subject of a future blog. Stay tuned…

COP27: why decisions on climate change made at this summit affect you?

COP27: why decisions on climate change made at this summit affect you?

From November 6 to 20, the 27th Conference of the Parties took place in Sharm el Sheikh, where state leaders met in search of agreements against climate change and the definition of an action plan to deal with the challenges current. In this blog we reveal the conclusions about this conference and why this topic should interest you.

Climate change…I´ve heard about it, but why should I care?

When we talk about climate change, a large part of the population relates it solely to the increase in temperature. And yes, they are right, the severity of climate change is evaluated through the increase in temperature, but it is the consequences derived from this increase in temperature that should concern us, as well as its causes, in order to combat it. Listed below some relationships that seem somewhat contradictory:

Cyclical changes in the climate have always existed, this is one more: yes and no. For 100 thousand years there have been very considerable climatic changes and in a cyclical way. However, with the arrival of the Holocene, 10,000 years ago, the temperature on Earth stabilized, only varying its average temperature within a range of one degree Celsius. This facilitated the development of a stable and predictable planet. It is, in fact, the only period in which we can ensure that the development of human life can take place. However, human activities and the consequent increase in greenhouse gases in the atmosphere have made us leave the Holocene, entering the Anthropocene, an unprecedented situation, as can be seen in the graph below.


This time is characterized by an exponential increase in temperatures, as you can see in the graph below, extracted from documentation of the Intergovernmental Panel against Climate Change (IPCC).

Valérie Masson-Delmotte et al., “Climate Change 2021: The Physical Science Basis,”

The temperature rises, but it is colder in winter: the entry into the Anthropocene and the rise in temperatures have meant that we are at risk of completely destabilizing the Earth’s atmospheric processes and breaking their balance. It is precisely this imbalance that causes more extremes in temperatures, both in winter and summer. The graph shows the frequency of extreme events that would exist depending on potential future temperature increases.

It rains more, but there are more droughts: an increase in the Earth’s temperature also affects the temperature of the oceans. Since warm water occupies more, this carries a risk for all coastal areas that could be affected by the rise in sea level, and also has an impact on the progressive melting of the poles (whose decrease in surface area also reduces the capacity of the Earth to reflect solar radiation). However, what is not so immediate is the alteration of the water cycle: as there is more water vapor in the environment, more intense storms are produced. This can lead to heavy and frequent flooding, as well as the occurrence of hurricanes. In fact, events like Hurricane Sandy in 2012 are estimated to occur annually starting in 21001. But what about droughts? When there is an increase in temperature, a greater amount of water evaporates from the soil (again contributing to the destabilization of the water cycle). When it returns in the form of intense rains to the ground, the ground is not capable of absorbing this amount of water at this speed, which contributes to floods derived from these intense precipitations. In addition, due to other types of processes, the absorption capacity and quality of the soil is currently reduced This has several consequences, such as the lack of food security. To learn more about this topic, I recommend this documentary: “Kiss the Ground”.

Therefore, the problem of climate change is not only the increase in temperature, but also all the consequences derived from it and the imbalance that it implies in the ecosystemic services the Earth provides. For all these reasons, the temperature limit is set at 1.5ºC, which is what allows it to operate in a safe environment. However, it seems easy to overstep it.

And what has been decided at COP27? Are the agreements that have been made enough?

Currently, we are not doing enough reduce GHG emissions and stay within the limit of 1.5ºC of temperature increase. Although there are different opinions about the results of COP27, a fairly general feeling is that, although the 1.5ºC target set in the Paris Agreement and renewed at COP26 in Glasgow has been maintained, much more needs to be done. In particular, the countries that emit the most have not committed to eliminate fossil fuels, nor to establish new agreements to contribute to the mitigation of climate change2.

However, a positive point of COP27 is its support for the most vulnerable countries, focusing the discourse on climate justice. Indeed, the harshest consequences of climate change end up being suffered by those countries that contribute the least to it and are more vulnerable. In fact, according to the 2018 Lancet Countdown Report, it is estimated that there could be one billion climate migrants.

Every tenth of a degree counts. The consequences of not acting and even temporarily exceeding this limit of 1.5ºC can lead to severe risks, some of which may be irreversible, according to the latest IPCC report. Globally and in a coordinated way, we have to adapt to these new circumstances, but also mitigate the future consequences of climate change. However, these mitigation and adaptation actions can only be applied at the local level. To give you some ideas of what can be done, I recommend a project we are working on at CARTIF, as well as provide additional references.

How does CARTIF contribute to the fight against climate change?

At CARTIF, especially from the Energy and Climate Policies area, we work on the development of models (at different scales), tools and solutions to analyze climate change and propose adaptation and mitigation solutions. In particular, in the RethinkAction project (GA 101037104) coordinated by CARTIF, we will develop an integrated evaluation platform to simulate and evaluate adaptation and mitigation solutions based on land uses. This analysis will be carried out both at a local, European and global level, as well as over time, which will allow both the general public and those in charge of making decisions to better understand the impact of its application. To do this, we will develop system dynamics models that we will apply both in the 6 case studies (representative examples of the impacts of climate change), and at a European and global level, and we will rely on georeferenced satellite information.

If you want more information…

I propose the consultation of three sources.

1. First of all, the most relevant documentation is that generated by the United Nations Intergovernmental Panel on Climate Change (IPCC), where reports are periodically generated to assess the climate change situation, focusing on various areas. In particular in the latest report they focus on the impacts of climate change, adaptation and vulnerability.

2. Secondly, I suggest the simulator of the EN-ROADS tool, developed by CLIMATE INTERACTIVE and MIT to analyse future scenarios and the consequences on temperature depending on the policies applied in various fields such as energy, transport, etc. .

3. Finally, it is worth highlighting the work of the Stockholm Resilience Center and the research orchestrated by Johan Rockström. These experts have analysed certain limits (planetary limits) in a series of areas that should be respected (see image below). They are points of no return where, once passed, we could not go back and they would cause the functioning of the earth to get out of control. As can be seen, many of them are related to climate change, but also to the pollution we generate, the use of water, etc.

Source: https://www.stockholmresilience.org/research/planetary-boundaries.html

In addition to being able to consult the scientific articles where this theory is exposed (here I leave an article), I recommend viewing the documentary that they have made about it, called “Breaking boundaries: The Science of Our Planet”. According to the documentary, the main message is hopeful: we still have time. It also highlights four main lines of action:

  1. Reduce greenhouse gas emissions to zero
  2. Protect all those terrestrial elements that contribute to absorbing our impacts (wetlands, soils, forests and oceans)
  3. Change our diets and the way we produce food
  4. Move towards a circular economy.

While many decisions should be made at a higher policy level, how can you use your voice, your vote, and your choices to contribute to this fight?

Your world depends on it.

1 Georgina Gustin, “U.S. Coastal Cities Will Flood More Often and More Severely, Study Warns,” Inside Climate News, June 7, 2017. https://insideclimatenews.org/news/07062017/coastal-flooding-extreme-sea-level-rise-forecast

2 Statement by President von der Leyen on the outcome of COP27 https://ec.europa.eu/commission/presscorner/detail/en/STATEMENT_22_7043

Overview of flexible demand management

Overview of flexible demand management

A few weeks ago, SmartEn1 association published an estimate of the benefits that could be achieved through flexible demand management. Recall that flexible demand management is the set of actions that stimulate consumers to change their usual pattern of electricity consumption in response to some kind of request.

It is considered that demand flexibility management will be one of the pillars to achieve the complete decarbonisation of the energy system. As the weight of classic generation systems, based on fossil fuels, decreases, it will become more difficult to match production with demand, since renewable energies are not controllable. This problem can be solved by storing energy in some way, such as hydrogen generation, heating water and using batteries. But, in addition to storage, attempts can be made to shift demand to coincide with times when renewable generation is most abundant. If demand is flexible, this could be done without prejudice to the consumer.

Let´s go back to the SmartEn report. They have used electricity market models and estimates of consumption and generation for 2030 published by the European Union and have come to some interesting conclusions. The first is that in 2030 there will be 164 GW of flexible power available in Europe to ramp up (consume less in the case of demand, generate more in the case of generation) and 130 GW of flexible power to ramp down. In terms of energy this is 397 TWh and 340.5 TWh respectively. To put these figures in perspective, all the nuclear power plants in Spain typically produce around 60 TWh per year, or that Europe’s electricity demand in 2021 was 3,399 TWh per year, or that Europe’s electricity demand in 2021 was 3,399 TWh2 per year.

Source: https://smarten.eu/report-the-implementation-of-the-electricity-market-design-2022-smarten-monitoring-report/

Exploiting demand flexibility will reduce the price of electricity because it can be managed to increase the use of renewable energy. The report estimates that these savings could amount to 4.6 billion euros. The increase in the use of renewables would occur because up to 15.5 TWh of renewable energy would not be wasted and would not have to be “thrown away” because the system, thanks to flexible demand management, will be able to consume them when they are available.

If we take into account that the trigger for the whole transformation we are undergoing is the fight against climate change, the report estimates that flexible demand management could lead to 37.5 million tonnes less greenhouse gas emissions than if demand flexibility were not used. This would represent 8% of total emissions and would allow the power generation sector to exceed Target 553, i.e. to have reduced GHG emissions by 55% by 2030 compared to 1990 emissions.

The energy transition could threaten security of supply, i.e. the everyday gesture of flicking a switch and the light coming on could no longer be so commonplace. The report picks up on this threat and says that by 2030 Europe will have a generation capacity shortfall of 60 GW. Solving this problem by building generating plants could cost around 2.7 billion euros, an investment that could be avoided if 60 GW of flexible demand were made available. Related to security of supply are balancing markets, where energy is sold to avoid problems in the stability of network. If these markets were given access to flexible demand management, SmartEn estimates that the price of energy in these markets could be reduced by 43% to 66%, which would ultimately benefit consumers. The distribution grid may also face problems in ensuring its proper functioning when the presence of distributed renewable generation gains the expected weight. To solve these problems, it would be necessary to invest between 11.1 and 29.1 billion euros less than expected if flexible demand were to be managed correctly.

The end consumer would also benefit from flexible demand management, not only if they have loads that are flexible, such as electrified air conditioning or electric vehicle charging, to name two, but they will also have to pay less in terms of grid usage tolls. SamrtEn`s report estimates that these terms would result in direct cost reductions for consumers of up to 64% per year, some 71 billion euros in total. It would also benefit from indirect cost resuctions due to lower energy prices, reduced investment in the distribution network to keep it up to date and reduced costs associated with greenhouse gas emissions. The report estimates that this indirect reduction would be around €300 billion.

Source: https://www.consilium.europa.eu/es/infographics/fit-for-55-how-the-eu-will-turn-climate-goals-into-law/

From the SmartEn report it seems that there would be nothing but benefits if flexible demand is managed correctly. So is flexibility already being exploited for the benefit of the energy system, consumers and the environment? The answer depends on the country, but in general, progress is slow. In the case of Spain, steps have been taken to define the role of the independent aggregator in the management of flexibility, but the necessary regulation has not been developed and, therefore, there are still no business models that can attract any type of consumer. The association Entra Aggregation and Flexibility has just presented a roadmap for demand flexibility according to which independent aggregators and market adaptation will be ready by the end of 2023. A plan that seems very ambitious considering the delays that have been dragging on, but which, if fulfilled, would represent a great step forward in achieving the decarbonisation objectives sought by both the Spanish government and the European Union.

Also in Spain we find an opportunity for flexible demand participation through balancing markets, where very large consumers can obtain economic benefits thanks to their flexibility. In addition to this, the first auction has recently been held. Consumers with flexibility have committed to reduce their demand by the amount they have bid when rewuired to do so by the system operator, for which they will receive a remuneration of 69.97€/MW. The bad news is that only 497MW have been allocated.

Demand-side flexibility management is set to be an important element in the new energy system. It can be achieved through voluntary and remunerated mechanisms as long as consumers adapt quickly enough and regulation is favourable. If this is not achieved, we will learn to be flexible by imposing restrictions on consumption.

1 https://smarten.eu

2 https://datos.enerdata.net/electricidad/datos-consumo-electricidad-hogar.html

3 https://www.consilium.europa.eu/es/policies/green-deal/fit-for-55-the-eu-plan-for-a-green-transition/

4 https://www.ree.es/es/sala-de-prensa/actualidad/nota-de-prensa/2022/10/el-sistema-electrico-peninsular-cuenta-con-cerca

Heating: alternatives to gas that are easy on the wallet

Heating: alternatives to gas that are easy on the wallet

Figure 1. Tracing Valladolid heat networks. Source: SOMACYL

The COVID-19 hangover has left us with a supply crisis with long queues (not only at the supermarket) that has increased the prices of equipment and all kinds of components. In addition, the armed conflict between Russia and Ukraine has led to an energy crisis with gas prices rising steadily.

Faced with this uncertainty and the growing fear of being cold in winter, some neighbourhood communities have started to connect to district heating networks (or heat networks). In Aranda, for example, 1950 homes will be connected to a biomass thermal network. The same is happening in Valladolid, where new heat networks are being installed in the neighbourhoods of Huerta del Rey, Parquesol and Villa del Prado. In other neighbourhoods, according to RTVE, residents’ associations are deciding to turn off central heating in response to rising prices, which could lead to an increase in the number of people living in energy poverty. In this context, the latter would mean people staying cold in their homes for fear of a high energy bill.

But, what are heat networks?

Heat networks or district heating networks are heat (or cold) production facilities that supply energy to each dwelling through underground pipes. Among the major advantages, compared to individual systems (the usual household boilers), are that heat networks allow the integration of renewable energy sources to increase independence from external fossil fuels, reduce emissions and lower costs for end-users. Other benefits include the removal of individual equipment from indoor spaces, which means more usable space available inside homes, and being able to offer a supply service independent of fossil fuels (and their price rises). Their main disadvantage is that they often require extensive work to prepare for the installation of pipework, traditionally involving the construction of large production plants with tall and aesthetically unattractive chimneys, and are simply not known to the general public, nor the benefits they can provide (especially in the case of Spain).

Then, affect the urban landscape of cities?

The answer is not necessarily. The New European Bauhaus (NEB) initiative aims to improve the quality of life of citizens through the joint promotion of the principles of Beauty, Sustainability and Inclusion in our environment, which is equivalent to good, beautiful and for all.

These principles focus on reconnecting with nature, regaining a sense of belonging and fostering participation, sustainability and circularity. In the case of heat networks, this holistic approach can be achieved in different ways.

As regards the sustainability pillar, the use of renewable energy sources (geothermal, solar thermal, biomass, biogas, recovery of surplus heat from industry) can be increased in thermal networks, as is being done at a general level in the sector to reduce CO2 emissions and other pollutants, but also, for example, through the revaluation of ashes or forestry waste.

As regards the social dimension and inclusion, by integrating more sustainable alternatives and supplying heat or cooling to a large number of households, affordable, secure and flexible heat or cooling supply can be promoted, thus reducing cases of energy poverty. In addition, digitalisation and the combination of networks with energy communities promote citizen participation and inclusion in the energy transition, where they can discuss, give feedback, engage in demand-side management strategies and even encourage users to become prosumers of heat.

But how can heat networks be made beautiful? At CARTIF, we have found that, through the generation of green spaces (such as parks) or multi-purpose spaces, it is possible to make the power plants beautiful spaces integrated into the urban, cultural or educational landscape. In addition, it is possible to reduce the visual impact of heat networks by burying the installations, and thus also the possible social rejection associated with the aesthetic component of these supply networks.

A case study in Heerlen, the Netherlands.

A very illustrative example of the successful application of the New European Bauhaus principles to heat networks is the network in Heerlen (Netherlands), which supplies 350 households with heat and cold thanks to geothermal energy. This network has boreholes at different temperature levels that allow it to provide heat of around 40°C in winter and 16°C of cooling in summer. The installation uses old coal mines as underground thermal storage and also uses surplus heat from a nearby steel industry, which would otherwise be lost to the environment. This could only be promoted in Spain if the houses were first insulated in order to lower the temperature required for heating and thus lower the temperature of the district heating networks. In Heerlen, at each substation each user would have an auxiliary heating system (which could be heat pumps) to meet their thermal demand. Thus, its generation is sustainable and guarantees affordable prices for citizens.

Moreover, the network’s generation plant has a modern and innovative aesthetic that blends in with the urban environment and is part of a multifunctional building that includes a supermarket, a café, a conference room and a library. In this way, far from having a negative visual impact or provoking rejection, it has become an iconic meeting point in the city.

Figure 2. Outside design of the heat network plant in Heerlen (Netherlands). Source: Smart Cities Marketplace

All this work on heat networks towards a more sustainable, inclusive and beautiful future is possible thanks to the fact that CARTIF is participating in several projects studying heat networks from different perspectives. Among them, REUSEHEAT and REWARDHEAT, where new generation heat networks are demonstrated with the integration of heat recovery from different sources, a project together with the JRC to study the NEB perspective on heat networks in Europe, or the NetZeroCities cities mission platform, where CARTIF will support cities to promote this kind of initiatives.

If you want to know more or need help with the NEB initiative or heat networks, count on us!

CARTIF is a Cervera Excellence Centre, granted by the Ministry of Science and Innovation and the CDTI, under the file number CER201910.


Andrea Gabaldón: Energy researcher. Experince in energy modelling of district and building systems, district thermal networks, positive energy districts and energy communities. She works in european projects such as LocalRES, ATELIER and NETZEROCITIES