CITIES invites to webinar: Data-Driven Technologies for Energy Efficiency and Flexibility

CITIES invites to webinar: Data-Driven Technologies for Energy Efficiency and Flexibility

Workshop / Webinar August 12, 2020, 9:00 AM – 12:00 PM CEST

In the quest for fossil-free cities and a fossil-free building sector, there is continued need to maximise energy efficiency of buildings and energy systems in cities. Even the limited energy use should to a maximum possible extent come from renewable sources, and the classical challenge of balancing demand and supply becomes an issue, which calls for flexible operation of all units.

Contemporary digital and data-driven methods are key to optimize the operation of buildings and district energy systems such that use of fossil fuels can be minimized without compromising on comfort and functionality of the built environment. The workshop will give an overview of potentials and state-of-the-art technologies in the field.

Sign up here for free!

Lots of inspiration in reports: Innovation for sustainable and smart cities

Lots of inspiration in reports: Innovation for sustainable and smart cities

The Danish / Swedish EU-supported project Smart Cities Accelerator has recently released all reports, technical papers etc. on a brand new homepage. Smart Cities Accelerator was based on CITIES research and findings and has tested the methodologies.

Please take a look at the many reports about energy efficiency improvements and energy renovations, digitization potential in the district heating network, energy communities, and legislation etc. And learn how to use Open Innovation Calls as a tool to get in contact with small startups with great ideas and solutions for complicated energy problems like power peak shavings.

In the period 2016-2020 four universities (DTU, Copenhagen University, Lund University, Malmö University), five municipalities (Copenhagen, Høje-Taastrup, Malmö, Lund, and Båstad) together with three energy companies (Høje Taastrup Fjernvarme & Kraftringen and E.ON both Sweden) have worked cross-disciplinarily.

The reports are in Danish, Swedish and English.

Nominated for the EU REGIOSTARS Awards

SCA ended in February 2020. The project was supported by the EU’s regional programme – Interreg Øresund-Kattegat-Skagerrak. The programme has been very enthusiastic about SCA. For two years in a row, Anne Marie Damgaard as project manager has been invited by SCA’s Interreg contact to apply for the EU REGIOSTARS Award. This year, she has followed the call and now the project is online and anyone can vote for it.

The REGIOSTARS Awards are an annual awards ceremony for EU-funded projects that show the way to good regional development and innovation. The projects should inspire other regions and project managers. There are five categories – Interreg has placed SCA in the category: Sustainable growth – Circular economy for a green Europe.

A jury will select five projects from each category in July. On July 9, they unveil the finalists, and at the same time, the European Commission’s Directorate General for Regional and Urban Policy create a real voting module on web to find the REGIOSTARS 2020 public choice award.

Please, give your likes here and read about the other projects:

The photo is from February 4, 2020, when SCA held a final conference in BLOX in Copenhagen. Photo: Mikal Schlosser
The photo is from February 4, 2020, when SCA held a final conference in BLOX in Copenhagen. Photo: Mikal Schlosser
Classical mathematics (still) solves the challenges of the green transition at the grid

Classical mathematics (still) solves the challenges of the green transition at the grid

Everyone talks about AI and machine learning, but a demo project with a water tower shows that a model with stochastic differential equations can describe energy flexibility surprisingly well with just a few intuitive parameters.

If the CO2 emission is to be reduced, the proportion of renewable energy sources must be significantly increased. If at the same time, the cost of the green transition is to be kept down efficiently, there is a great need for energy flexibility on the part of consumers, so that they use electricity when there is plenty of green energy in the electricity grid. And here is the price of electricity a co-player.

Rune Grønborg Junker, Postdoc at DTU Compute, together with colleagues and with the help of Grundfos, has found an intuitive way in which mathematical models describe how energy-flexible consumers react to electricity prices. While many focus on AI and machine learning, the researchers here have returned to classical mathematics to find the answer.

– At AI, you do a lot, but you don’t quite know what happens. Here we have done something intuitive that makes sense. When we test our model, we can understand the things we see because we apply stochastic differential equations. The differential equations describe how people behave on average. While the stochastic part describes how in practice there is a degree of uncertainty in how people actually consume energy. You could say that this is a kind of formulating physical laws for energy, says Rune Grønborg Junker.

– Right now, though, AI doesn’t work at all for such a description either. It may be that it’s going to do it sometime, but we’re nowhere near having something that works. This, on the other hand, is something that works now. In addition, AI should estimate maybe 500 numbers, here just eight numbers. It makes a significant difference to the robustness, he says.

Uses water tower as an electricity consumer

In the demo project, Rune Grønborg Junker and the team at DTU Compute have used a water tower at Grundfos to investigate price-based management of flexibility.

Grundfos has implemented a controller based on the energy price in the water tower. The price of electricity helps to control how much water they will have to pump up in the tower, so that there is enough water for those who need it, but then you pump it up with the electric pumps as cheaply as possible. The water tower here symbolizes the ordinary consumer.

The Rune Grønborg team has based on real data from the water tower, found the connection between electricity prices and electricity consumption. They have successfully described this relationship using a model of stochastic differential equations. By predicting consumption based on this model, they have calculated how to turn up and down the electricity price to control the water tower’s electricity consumption so that it fell most appropriately.

The result showed that if the owner of the water tower could predict the future 100 %, then by buying into the Scandinavian spot market, the owner could save 5.4% on the electricity bill. By contrast, using DTU Compute’s model would save 4.1%, but at the same time, that simulation is true to reality.

– As such, savings of either 5.4% or 4.1% in energy flexibility don’t count. For it will be impossible to predict the future 100%. We have focused on showing that using the model can take advantage of flexibility 76%, so it is reasonably close to being as efficient as it can be. If we focus more on optimizing the model, we must expect the result to be even better, says Rune Grønborg Junker.

Fig. 1. Sketch of the water supply network used as model of local energy consumers. is the flow of water into pressure zone 1, with pressure .

Examines the possibilities of energy flexibility in the balance markets

The water tower is a simple system where the dynamics are controlled. Once the tower is completely filled, there is no room for more water.

– Therefore, there is virtually no difference between reality and simulation. And we have used real data from the water tower, so it should be easy to use the model in real life. Just as it fits, for example, the battery in an electric car, which must also be discharged when it is filled up completely, because there is then no room for more, says Rune Grønborg Junker.

In this project, we have chosen to focus on the simplest market, namely the spot market, but it is expected that there is more value in using energy flexibility in the balance markets. The team is therefore now investigating the possibilities there.

DTU Compute and Grundfos are the first to test price management for flexibility in this way. The demo project is based on the work Rune Grønborg Junker has done in his PhD, which he defended in February 2020.

The demonstration project is mainly paid by the Innovation Fund Denmark through the CITIES project (Centre for IT–Intelligent Energy Systems) and the FED project; Flexible Energy Denmark. Grundfos and Bjerringbro Community Waterworks are responsible for data on the water tower. The results of the test case have just been published in the journal Applied Energy. Learn more here:

CITIES-forskere foreslår CO2-afgifter og CO2-fond for industrien

CITIES-forskere foreslår CO2-afgifter og CO2-fond for industrien

Forslaget bygger bro mellem Klimarådets forslag om og Dansk Industris afvisning af en indførelse af klimaafgifter for industrien.

Debatten om CO2-afgifter for industrien er for alvor kommet på bordet, selv om klima-, energi-og forsyningsminister Dan Jørgensen har afvist at få det med i Klimaloven. I sidste uge åbnede statsminister Mette Frederiksen for muligheden for at gå i gang med en grøn skattereform.

Det glæder forskerne i CITIES-projektet – Danmarks største projekt inden for smartere energisystemer. De foreslår nemlig, at Danmark indfører CO2-afgifter for industrien, men at pengene skal indgå i en CO2-fond, som samtidig støtter industriens grønne omstilling.

Onsdag den 17. juni 2020 forklarede centerleder for CITIES og professor på DTU Compute Henrik Madsen sammen med professor Brian Vad Mathiesen og Karl Sperling fra Forskningsgruppen for Energiplanlægning på Aalborg Universitet deres forslag i et debatindlæg i Politiken Miljø & Klima.

Forslaget går på, at CO2-fonden primært skal støtte projekter, der gør energiforbruget fleksibelt. Og projekter, som øger energieffektiviteten i en proces, direkte ved mindre energiforbrug eller ved hjælp af opgradering af spildvarme til fjernvarme eller anden opvarmning. Herunder øger genbrug af drivhusgasser fra eksempelvis mineralogiske processer.

Forskerne peger på, at forslaget bygger bro mellem Klimarådet og Dansk Industri ønsker.

– Vi vurderer, at der ligger et stort vækst-, eksport- og effektiviseringspotentiale i at udvikle og implementere bæredygtige, effektive og fleksible løsninger i industrien, skriver forskerne blandt andet.

Torsdag den 18. juni 2020 var Henrik Madsen gæst i DR-programmet Orientering på P1 for at uddybe forslaget.

Her forklarede han blandt andet, at fonden er tænkt som hjælp til selvhjælp for industrien:

– Med det her forslag vil vi gerne undgå, at industrien flytter til udlandet. Vi vil gerne bevare de danske arbejdspladser, og vi ser det her forslag med CO2-bundne afgifter, som et forslag, der kan accelerere den grønne omstilling, for vi har virkelig travlt for at nå 70-procentsmålet. Vi skal arbejde tre gange hurtigere, end vi har gjort siden 1990. Men vi kan samtidig accelerere den grønne omstilling på en måde, der giver grøn vækst. Det er vi ganske overbeviste om, såfremt vi gør det rigtigt, sagde Henrik Madsen blandt andet.

Han forklarede også, at der allerede er værktøjer, der kan hjælpe industrien med grøn omstilling, fx værktøjer til digitaliseret styring af energien så produktionen, så man får fremmet den grønne omstilling af industrien generelt.

Indslaget med Henrik Madsen kan høres i linket herunder. Det begynder 01:01:19 inde i udsendelsen som første indslag efter Radioavisen klokken 17:

Læs også de to task force-rapporter, som CITIES tidligere har udarbejdet:

  • Energiafgifter for fremtiden – notat. Notat udarbejdet af ’CITIES Task Force Udvalg omkring energiafgifter og rammebetingelser’, bestående af nøglepersoner fra Danfoss, Teknologisk Institut, Grundfos, Ørsted, Grøn Energi, Tomorrow, Aalborg Universitet, og Danmarks Tekniske Universitet.
  • Testzoner for Udvikling og Afprøvning af Fremtidens
    Energisystem og Rammebetingelser (regulatoriske frizoner). Notat udarbejdet af CITIES Task Force Udvalg omkring energiafgifter og rammebetingelser. Udvalget består af nøglepersoner fra Danfoss, Teknologisk Institut, Grundfos, Ørsted, Grøn Energi, Tomorrow, Aalborg Universitet, og Danmarks Tekniske Universitet.

Digitalisering skaber store gevinster i Svebølle-Viskinge Fjernvarmeselskab

Digitalisering skaber store gevinster i Svebølle-Viskinge Fjernvarmeselskab

Sænkning af fremløbstemperaturen med 10 grader, markant reducering af varmetab samt fastholdelse af varmeprisen.

I magasinet Dansk Fjernvarme kan du læse mere om gevinsterne ved datadreven styring og visualisering i Svebølle-Viskinge Fjernvarmeselskab (m bl.a. Svend Müller).

Her samarbejder DTU – Technical University of Denmark (m Henrik Madsen, Per Sieverts Nielsen samt Dorthe Skovgaard Lund m.fl.) med ENFOR A/S (m bl.a. Mikkel Westenholz) om udviklingen af metoderne gennem IDASC (hjemsted på Gate 21 m Karolina Huss), CITIES Innovation Center samt vores tidligere Smart Cities Accelerator. Og ABB (partner i FED-projektet) er med i aftestningen.

Læs også artiklen her:

Svend Müller, bestyrelsesformand i Svebølle-Viskinge Fjernvarmeselskab (tv) og Mikkel Westenholz, CEO i ENFOR. Foto: Hanne Kokkegård
Svend Müller, bestyrelsesformand i Svebølle-Viskinge Fjernvarmeselskab (tv) og Mikkel Westenholz, CEO i ENFOR. Foto: Hanne Kokkegård

Energy communities: Good or? CITIES is looking behind the hype

During a new demo project at CITIES – Centre for IT-Intelligent Energy Systems – Danish Energy and DTU Compute will make a simple analysis of the impact of energy communities on the national grid.

Energy Communities is a new player on the energy market that can help incorporate larger amounts of sustained energy in the energy system.

Usually, energy communities include prosumers (consumers of energy that produce energy at certain times) that can have or have not the possibility to store energy, e.g. via batteries or thermal energy storage. Although these concepts can sound attractive to different stakeholders, it is not yet clear what the impact of ‘energy communities’ on different distribution systems is. 

I a new demo project Danish Energy (a non-commercial lobby organisation for Danish energy companies) and DTU Compute will look at the impact of energy communities on three different grid layouts – urban, suburban and rural areas of Denmark – to estimate the consequences of different set-ups of energy communities on distribution grids, as well as to find the energy community set-ups that require further research.

– Of course, the idea of creating sustainability with local energy production sounds very good. But we are looking behind the hype. We are not focusing narrowly on the small energy community but look at the horizon to understand the whole role of these energy communities to see the impact on the whole national grid, Dominik Franjo Dominkovic, Postdoc at DTU Compute, says.

– We hope that the results of this project can serve as a solid foundation for designing future flexibility services and tariffs for energy communities, taking into account the different structures (shapes) of energy communities, Jan Rasmussen, Head of Department at Danish Energy, says.

Different kinds of energy communities
The energy communities are not very good defined. And we only have seen very few of them so far.

It could be only two players exchanging their energy in real-time. It could be an energy community far from the owners who just sell the energy to the marked or is used in the houses there. It could be in the city or far out in the countryside.

Some of them could store energy, e.g. via batteries or thermal energy storage for later use by themselves when the energy production is low or for selling at the energy market. Sometimes they will need to get energy from the grid to secure enough energy for the consumers. You could also think of energy communities where the energy is not as green as the energy from the grid.

Therefore Danish Energy and DTU Compute will make a simple analysis of the impact of energy communities on three different grid layouts with a small, a medium and a large setup.

Some of the questions that will be tackled are how an energy community should be billed and how the distribution grid tariffs should be constructed. The demo project looks at both the economy and CO2-reduction.

– The idea is to see in which setup these communities benefit the distribution grid and in which setup they do not support the distribution grid at all or perhaps even having a critical impact for the grid. At the end we would like to see how changes in the energy prices will affect the situation, Dominik Franjo Dominkovic says.

Danish Energy is experiencing an increasing interest in energy communities covering housing association and parts of larger cities.

– It is of great importance, those energy communities are rewarded if supporting the grid, and are integrated into the electricity system in a non-discriminated way, together with all other electricity users. As energy communities can have many ‘shapes’, it is needed to create a foundation for designing future flexibility services and tariffs. We believe that our engagement in the CITIES project can provide this, Jan Rasmussen says.

Learn more about the demo project

See also the YouTube-video from Smart Cities Accelerator, where we also researched energy communities.

District heating tests climate-friendly air conditioning based on cooled hot water

New CITIES demonstration project explores how much energy it saves by connecting an absorption chiller to district heating as a green alternative to traditional air conditioning, e.g. in server rooms.

Danish version? Find it here:

There are not much ‘sales’ in district heating in the summer at the several hundred district heating companies in Denmark. A test with flexible and intelligent cooling at Grindsted electricity and heating (GEV) in the coming summer might help to change that a bit.

GEV has installed an absorption chiller, which has to cool two meeting rooms. The pilot chiller is a small unit of 2.5 kW. It cools the district heating water from 60 degrees to 13-18 degrees and passes it through a valve into a fan coil to cool the air.

The district heating industry should not really make money beyond for the cooperatives; the project for GEV is more about a green profile and about saving operating costs. Therefore, the partners in the project expect the project moves the power consumption, saves energy for cooling and thus speaks into the green transition because it does not use environmentally harmful coolant.

– These kinds of units could be very interesting especially for heating companies for selling cooling in the summertime when the demand for heating is low. If this project will be successful, the heating companies could find additional demands on heating and get a business case out of it. However, the solution is especially suitable for factories, big stores with refrigeration needs and server rooms, Dominik Franjo Dominkovic, Postdoc at DTU Compute and demo project leader at CITIES, says.

The  absorption chiller is the grey instrument at left.  The pilot chiller is a small unit of 2.5 kW. It cools the district heating water from 60 degrees to 13-18 degrees and passes it through a valve into a fan coil to cool the air.  Credit: GEV
The absorption chiller is the grey instrument at left. The pilot chiller is a small unit of 2.5 kW. It cools the district heating water from 60 degrees to 13-18 degrees and passes it through a valve into a fan coil to cool the air. Credit: GEV

Green energy or operational optimization 

The Danish company Energy Cool, which usually sells small installations, where electricity is used exclusively for cooling, develops the set-up. Here, a model has been further developed to convert district heating to cooling water, which is used for comfort cooling of the two meeting rooms, explains Henrik Thorsen, Director, Energy Cool:

– Our normal source of supply is electricity, but this project is extremely exciting, as we can combine green district heating here, which in the summer period is surplus of precisely during the period when most cooling is needed.

– This CITIES project opens up completely new opportunities, to increase our storage technology and utilize green energy, as well as increase flexibility, which can thus contribute to the green transition. We hope with the project to be able to help reduce energy consumption, ensure that green energy is used and utilize surplus heat for cooling, he says.

Energy Cool works with storage technologies to minimize power consumption and shift it across the clock when the power is produced green or to optimize operation.

DTU has installed sensors at GEV to collect data about temperatures from the meeting rooms and the district heating water in the building, as well as power consumption. Energy Cool will deliver the data from sensors via the firm’s own cloud solution during the period from late spring to late summer.

– We will get data in real-time and based on that we will be able to test a simple model for demand response in relation to the energy and district heating prices on the energy market. According to that also to shut down the cooling production and increase it on other times based on the price, Dominik Franjo Dominkovic says.

The need for ventilation created the idea

The idea originally came about because GEV should have installed ventilation in the company’s office building. It would cost DKK 2 million to install a ventilation system. In addition, the electricity bill would also be expensive.

– That’s why we started looking at cheaper options with completely different and more ‘green’ glasses. By thinking carefully about and collaborating with the right people, we have found that using cooled district heating water to cool down warm rooms with, says Leif Jørgensen, operations and project manager at GEV.

Here the power consumption will be low and GEV can use some water that the company already has. Initially, the project runs on a small scale. The absorption chiller is installed in GEV’s heating plant and cools the water and passes it on to the ventilation units in the two meeting rooms, which were connected to the mains on April 1.

– The whole scam about this is also that in the long term we expect to be able to cool our office building with quite a few cooling units, which cost almost nothing. We also expect that even in the future we will be able to produce the small amount of power that the system requires using solar cells. But that will be the next step. Now we need it to run in the two meeting rooms, so the server room and then likely the whole office building, says Leif Jørgensen.

He also mentions the purely aesthetic. Radiators quickly look a little ugly. Here the cooling unit in each room is the size of a radiator but smooth on the outside. Finally, there is also energy in cooling down. Even though it is cold air, it can be used for district heating, for example with a heat pump. However, it will require some investment.

– You could easily replace a number of radiators in our office house, and then have them produce heat in the winter and cold in the summer, so that the same heat pipes supply hot water during the heating season and cold water in the summer season. Such a solution will be interesting. There is clearly a perspective in trying something. That’s what we can get out of this collaboration with DTU and Energy Cool in CITIES, says Leif Jørgensen.

The market for cooling is growing rapidly

Henrik Thorsen points out that the market for cooling is growing rapidly due to global warming, as well as increased data consumption, which requires the expansion of technical installations.

– There are huge prospects in converting heat to cooling, and we are proud to develop customized solutions in collaboration with DTU and CITIES that benefits our customers and especially the environment, Henrik Thorsen says.

At DTU Compute Professor and Project Manager at CITIES Henrik Madsen also links the demonstration project to other projects:

– Like other CITIES solutions, the idea is that the final solution will be scaled up for use in several other contexts at Denmark’s new digital hub for smart energy systems, Center Denmark.

With the location at Kolding, Center Denmark is located near key national players in the energy market, such as Energinet, Ørsted, EWII, TREFOR and Danish District Heating.

This location will help ensure that Center Denmark becomes the hub of the new Energy Silicon Valley in Trekantområdet between Vejle, Fredericia and Kolding. Center Denmark has a close association with all four technical universities in Denmark, as well as a number of key players for a smart green transition.

Learn more about the demo project here.

Credit: EnergyCool

Energinet: PtX and sector coupling – the way to a climate-neutral energy system

Just as the Corona crisis closed Denmark and the rest of the world, Energinet Electricity System Operator released an extremely important new system perspective analysis: “System perspectives at the 70% target and large-scale sea winds”.

In the analysis, Energinet looks more closely at the need for the development of system solutions for the future we are facing with ambitious climate targets for 2030 and onwards towards a RE-based energy system, so that the conversion of the energy system is in line with the 70% reduction target in 2030 and the possibility of to utilize large Danish offshore wind resources – especially in the North Sea – optimally in the long term a climate-neutral energy system.

During the preparation of the system analysis, Energinet has also used research and results from CITIES’ especially in relation to the part of the report that discusses system operation and digital architecture, where AI can be used for automation of operations, better forecasting methods, etc. Topics related closely to knowledge from CITIES’ focus area.

The analysis presents a number of examples of possible long-term development paths for the energy system and is an important contribution to the planning and development of the electricity system by Energinet Electricity System Operator.

The analysis shows that Power to X (PtX) and sector coupling with gas incl. Hydrogen is important for efficient utilization of the large Danish offshore wind resources.

With a good system development in this area, Denmark can utilize the very large Danish offshore wind resources for electricity exports when the international market price is high, whereas production in hours with ample electricity production and low market value can be refined to high-value PtX fuels that can replace fossil energy consumption.

This maximizes the value of the Danish wind power, and the Danish part of the North Sea can secure significant greenhouse gas reductions in both a national and international perspective.


The analysis ‘System perspectives at the 70% target and large-scale offshore wind’ contains three parts:

• a focused analysis with examples of possible development paths for a Danish energy system that meets the 70% reduction target in 2030 (part 1),

• a long-term system analysis showing the prospects of utilizing large-scale offshore wind in 2035 (part 2)

• a summary of selected focus areas for Energinet Electricity System Operator (Energinet Systemansvar, in Danish) in relation to the 70% reduction target, the utilization of large-scale offshore wind and the long-term planning and development of the electricity system (part 3).

Find the analysis (English) here:

Press release (English) here:

Join summer school: Time Series Analysis – with a focus on modelling and forecasting in energy systems, August 2020

Venue: DTU and online, Copenhagen, Denmark Date: August 24-28, 2020 (registration before July 15. – Learn more in the link below)

Due to the COVID-19 situation: It will be possible, in any case, to participate in the summer school via online means. We will stream the lectures and will provide online interaction for all participants and assistance during exercises.

Learn more about the summer school and the cost of participation here: Summer School Announcement 2020

Watch the video from last year’s summer school

Material from Masterclass: Can district heating become self-learning?

Digitalization is an important element in the future of sustainable supply solutions. In recent years, the proliferation of consumption meters and temperature sensors in the district heating supply has created a great potential for using real-time data and artificial intelligence to make district heating greener and more economically sustainable.

On March 5 2020, Professor and Center Manager for CITIES Innovation Center Henrik Madsen gave a presentation on a masterclass at Gate21 (and the IDASC project): Can district heating become self-learning? Find the presentation material (Danish) at Gate21.

Henrik Madsen – Gate21 Masterclass March 5 2020