Material from CITIES final conference – November 9, 2020

Updated November 16, 2020


Could we be 100% fossil-free tomorrow? In the research project CITIES – Center for IT Intelligent Energy Systems – universities, industrial partners and utilities have been researching the use of data for energy optimization in cities for seven years.

At our final conference – November 9, 2020, we were focusing on how digitalization can accelerate the green transition and what it takes before we can take full advantage of digitalization.

Just over a hundred participants had signed up for the conference. In the videos, you only see the speakers on the right of the screen – while the participants are hidden.

Find the material – videos and PDF – from the day here below.

CITIES also participated in the Green Digitalization conference on November 10, 2020 – together with FED and DiCyPs projects: Find the presentations here:


Henrik Madsen, Project Manager, presentation:

PDF: CITIES Final Consortium Meeting Achievements and Recommendations

Olivier Corradi, CEO at Tomorrow: KEYNOTE: Challenges, status and possibilities:

PDF: The low-carbon transition: Challenges, status and possibilities, Olivier Corradi, CEO at Tomorrow

Jong-Bae Park, Professor and Head of Research Center for Innovative Electricity Market Technology, Konkuk University, Korea:

PDF: Collaboration Experience between DTU and Korea; including research topic of ‘Optimal Operation Strategy of Large-Scale CHP in District Heating System’

Pierre Pinson, Professor at DTU Elektro and Work Package Manager at CITIES:

PDF: Intelligent aggregation and markets

See also CITIES brochure:
Integrated Market for Electricity and Natural Gas – an integrated market for electricity and natural gas systems with stochastic power producers

Exploiting Flexibility in Coupled Electricity and Natural Gas Markets: A PriceBased Approach

Daniela Guericke, Assistant Professor at DTU Compute, Work Package Manager on CITIES & Anders Andersen, CTO at EMD International:

PDF: Methods for optimal operation and market participation of district heating systems

See also CITIES brochure::
Operational planning and bidding for district heating systems

Giulia de Zotti, Danish Energy Agency / DTU Compute:

PDF: Leveraging consumers’ flexibility for the provision of ancillary services

Carsten Rode and Christoffer Rasmussen:

PDF: Data-driven methods for characterizing the dynamics of buildings

See also CITIES brochure:
Storage in Thermal Building Mass – Utilizing thermal building mass for storage in district heating systems

Per Sieverts Nielsen, Xiufeng Liu, DTU Management & Adam Brun, Aarhus School of Marine and Technical Engineering:

PDF: Clustering of energy consumption for energy planning

See also CITIES brochure:
Clustering-Based Analysis – clustering-based analysis for residential district heating data

A framework for prediction and segmentation of daily energy load profiles of building clusters using machine learning

Dominik Franjo Dominkovic, Postdoc at DTU Compute:

PDF: Smart Cooling – Singapore, Grindsted and the future

See also CITIES brochure:
District Cooling – potential of district cooling in hot and humid climates

Karl Sperling, Associate Professor and Work Package Manager on CITIES, Jakob Zinck and Louise Krog Elmegaard Mouritsen, Post Doc, Department for Development and Planning at Aalborg University:

PDF: Simulation and planning for the future smart energy system

See also CITIES brochures:
Barriers and Recommendations to Innovative Models for Wind Power

Framework for strategic energy planning

Renewable Energy Systems – cross-border versus cross-sector interconnectivity in renewable energy systems

John Bagterp Jørgensen, Professor at DTU Compute and Work Package Manager on CITIES:

PDF: Model predictive control for smart energy systems

Carsten S. Kallesøe, Chief ing., Grundfos and Rune G. Junker, Postdoc at DTU Compute:

PDF: Flexibility concepts in practice; case study on water towers

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

Ben Kroposki, Director, National Renewable Energy Lab, Colorado, US:

PDF: Demand response solutions and perspectives

Shmuel Oren, Professor, University of Berkeley, California, US and Niclas Brok, PhD student, DTU Compute:

PDF: Market-Based Mechanisms for Mobilizing Electric Demand Flexibility Shmuel Oren with contribution from Niclas Brok

Peter Rathje, CEO, ProjectZero, Sønderborg:

PDF: CITIES and what’s next

Nina Detlefsen, Chief Analyst, Green Energy, Danish District Heating Association and Jan Hvidbjerg, Lead Analyst, Ørsted:

PDF: Suggestions for new energy taxes and net tariffs (reports from CITIES Task Force group)

See also the reports from CITIES task force group:

  • Nettariffer for fremtiden
    Notat fra nov 2020 om behovet for at gentænke nettariffer for at opnå 70 % reduktion i 2030 – 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.
  • 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.
  • Energy Systems Integration: Defining and Describing the Value Proposition. White paper from June 2016 about the coupling of energy systems/energy systems integration. This initiative was led by NREL – a main partner of CITIES, with help from DTU Compute and others.

Find all CITIES brochures

Check out CITIES Software Packages

Webinar on December 8: Accelerating the green transition using AI and energy system integration

Webinar on December 8: Accelerating the green transition using AI and energy system integration

Join us for free at this webinar: DECEMBER 8, 9:00 AM – 11:30 AM CET


A low-carbon society calls for fundamental changes in the energy system. Today energy systems are operated and planned so that the production follows the demand. However, an efficient implementation of a low-carbon society calls fora system where demand follows production. This highlights the need for a whole spectrum of methods ranging from energy system planning to operation. Most importantly, the flexibility at virtually all type of end-users on all aggregation levels has to be unlocked. In order to maximize the flexibility options, all aspects of energy systems integration and sector coupling, such as the energy-water nexus, have to be considered. 

The complexity calls for the next level of digitization and a need for new tailored methods, i.e. energy system-oriented AI, Big Data Analytics, Grey-Box Modelling, Cloud-Fog-Edge Computing, System-of-Systems, IoT, Resilience, User-involvement, and Data-sharing principles. This special session will provide a number of talks highlighting the status and challenges in achieving an efficient implementation of the future low-carbon society. 


  • Carsten Rode, Professor at DTU Civil Engineering, Moderator
  • Henrik Madsen, Professor at DTU Compute and Project Manager for the CITIES project: 10 years in the green transition: results, challenges and opportunities
  • Rune Grønborg Junker, Postdoc at DTU Compute: Dynamic and stochastic characterization of energy flexibility
  • Dominik Franjo Dominkovic, Postdoc at DTU Compute: Implementation of water sector into integrated energy models
  • Postdoc Sara Ben Amer and Senior Researcher Per Sieverts Nielsen, both DTU Management: Mapping of digitalization and ICT implementation in district heating
  • Razgar Ebrahimy, Postdoc at DTU Compute: Path to the digitalization of the energy sector
  • Technical Moderator: Energy Cluster Denmark

Sign up and share with your network:

Ny webinar-serie: Danmark og USA kan lære af hinandens energiforskning

Ny webinar-serie: Danmark og USA kan lære af hinandens energiforskning

DTU har sammen med det nationale danske Innovation Centre Denmark Boston udviklet en række forsknings-webinarer sammen med Ørsted, MIT og Tufts University i Boston samt Energinet og den nye forskningsklynge Energy Cluster Denmark.

Internationalt samarbejde og deling af viden er forudsætningen, for at verdens lande kan opfylde klima-målsætningerne. Danmark og USA samarbejder meget forskningsmæssigt inden for energi, men med en ny webinarrække håber Danmark at øge vidensdelingen.

DTU Compute / DTU – Technical University of Denmark har sammen med det nationale danske Innovation Centre Denmark Boston udviklet en række energiforsknings-webinarer sammen med ØrstedMassachusetts Institute of Technology og Tufts University School of Engineering samt Energinet og med webinar-teknisk hjælp fra den nye forskningsklynge Energy Cluster Denmark.

Det første webinar ’System Integration and Energy Conversion’ løb over nettet torsdag den 29. oktober 2020 med 170 deltagere, hvoraf 90 fulgte med fra udlandet; primært USA, men også Europa og Asien.

Forskningsattaché hos ICDK Boston Torben Orla Nielsen er tovholder på webinar-serien og ser en unik mulighed for at øge energiforskningssamarbejdet mellem USA og Danmark lige nu:

– USA står med ret konkrete udfordringer på transmission og integrationssiden, og det er et område vi i Danmark har stærke kompetencer indenfor.

– Løsningen af disse udfordringer kan være med til at bane vejen for danske arbejdspladser, da den danske vindindustri er stærkt repræsenteret i USA. Vi vil derfor arbejde på at samle de ledende stakeholders fra både forskningen og industrien for at skabe nye samarbejder, siger Torben Orla Nielsen.

DTU-professor: Vi kan lære af USA’s markedsstruktur

Henrik Madsen, der er professor og leder af afdelingen for dynamiske systemer på DTU Compute, forsker i brug af data i energisystemer. Han har været med til at sammensætte programmet, og han var moderator og holdt selv oplæg om integration af vindenergi i energisystemet.

Henrik Madsen ser et stort potentiale i forskningssamarbejde over Atlanten, selv om Danmark og USA allerede i dag samarbejder i en del forskningsprojekter inden for energiområdet:

– USA har fx en markedsstruktur, hvor man linker (elpris/produktion/planlægning) meget op på de fysiske forhold i elnettet. Det kunne vi i Danmark lære noget af. Omvendt arbejder Danmark meget med sektorkobling på tværs af forskellige energiformer, og det er oplagt, at USA tænker mere i de baner.

Behov for automatisering og realtids-data

På webinaret tog forskere og industri fat i, hvordan verden skal tackle de udfordringer og muligheder, der er forbundet med at udvikle digitale løsninger med brug af AI, IoT, prognoser, kontrol osv. til integration af store mængder af vedvarende energikilder i energisystemet på en konkurrencedygtig måde, samtidig med at man sikrer en optimal energidistribution og -transmission og udvikler nye markeder for fleksibilitet.

Professor Eric Hines fra Tufts University nævnte også, at 300 GW offshore vind ved østkysten af USA i 2050 er et realistisk senarie, fordi vindenergi i stor skala nu er absolut konkurrencedygtig.

Et klart budskab på webinaret var, at digitalisering, automatisering og brug af realtids-data i energisystemet er en forudsætning for en effektiv, sikker og smidig integration af vindenergi og anden vedvarende energi i stor skala.

– I et elsystem med behov for øget fleksibilitet og flere forbrugs- og produktionsenheder stiger kompleksiteten, og digitalisering er nøglen til sikker og effektiv drift, siger direktør i Energinet Peter Markussen, der er ansvarlig for Energinets internationale konsulentforretning og selv deltog med et oplæg på webinaret.

– Med webinar rækken får vi mulighed for at fortælle både om vores udfordringer og vores løsninger og dermed dele erfaring med amerikanske aktører og få adgang og inspiration til de bedste løsninger, siger han.

Kommende webinarer

Det andet webinar bliver i marts 2021, hvor temaet bliver slutbrugere, og hvordan man kan åbne for fleksibilitet i energiforbruget hos dem samt sektorkobling.

Det tredje og sidste seminar er planlagt til den 16.+17. juni 2021, hvor partnerne håber at kunne mødes fysisk i Boston.

Følg Innovation Centre Denmark Boston på LinkedIn:

VIDEO – Keynote speech with Henrik Madsen: Forecasting for the Green Transition

The last week in October 2020 the International Institute of Forecasters held it’s 40th International Symposium on Forecasting. Henrik Madsen, Project Manager at CITIES and Professor at DTU Compute gave a keynote speech: Forecasting for the Green Transition. His talk is now available on YouTubeclick on the play icon below or use the link below

In his talk, Henrik Madsen describes how the green transition implies that the power system will undergo a fundamental change from a system where the power production follows demand to a system where the demand follows the renewable power production. This implies that energy forecasting will play a central role in the green transition.
Today energy load forecasting is a rather easy task, but in the future demand response methodologies will become widely used and consequently demand and prices will become more volatile and less predictable. This talk will demonstrate that by taking account of auto- and cross-covariances when reconciling forecasts, the accuracy can be significantly improved.

In Henrik Madsen’s talk, he also presents state-of-the-art methodologies for renewable energy forecasting. In particular, he and his colleges’ research is focused on methods for multivariate probabilistic forecasting of load and renewable power generation.

The research also shows that integrated forecasting across domains (wind, solar, load, prices, …) will become essential, and replace more silo-oriented and independent tools for individual areas like wind power. Therefore his talk demonstrates that full multivariate probabilistic forecasts will become essential to obtain reliability and profitability in the operation of future low-carbon energy systems.

New paper: Unlocking energy flexibility of municipal wastewater aeration

A new paper from CITIES / DTU Compute & Krüger A/S – download for free the next few weeks!

A novel economic optimal control strategy suggests that the power consumption in wastewater treatment can be flexible since the water is treated in large tanks with long retention times where specialized aeration equipment is repeatedly switched on and off.

By controlling these switching times with respect to nutrient concentrations, electricity consumption can be predicted and shifted in time and hence provide short-term demand-side flexibility.

The proposed principle is used to reduce the operating costs of a wastewater treatment plant by enabling the flexibility to distribute the aeration load to periods with less expensive power prices.


  • Significant cost savings for wastewater treatment by shifting power consumption
  • Favourable to exploit instantaneous price differences in multiple power markets
  • Optimal energy consumption of wastewater aeration using switching times


Authors: Niclas Brok and Henrik Madsen from DTU Compute & Thomas Munk-Nielsen and Peter A. Stentoft from Krüger A/S.

Energy Webinar on System Integration and Energy Conversion

CITIES participate in this webinar series on System Integration and Energy Conversion. The first webinar is on Thursday, Oct. 29. Join us and hear the presentations from CITIES – Centre for IT-Intelligent Energy Systems IP Henrik Madsen and our partners Ørsteds (Ørsted Onshore North America) and Energinet and others. Find the link to sign up in the posting below

The Webinar Series begins on October 29th where Innovation Centre Denmark Boston, in collaboration with Massachusetts Institute ofTechnologyDTU – Technical University of DenmarkTufts UniversityEnerginet, and Energy Cluster Denmark, will host an Energy Webinar on system integration and energy conversion. We hope you will join us for this informative and worthwhile event.

Sign up for the seminar here:


After seven years of research CITIES project comes to an end. We are pleased to invite you to our annual meeting – and this year also – final conference Monday, November 9, 2020 – at DTU and Online.

This year we also collaborate with two other projects – DiCyPs and FED. Tuesday, November 10, 2020 CITIES invite you to join our joint conference at EWII in Kolding in person or online.

Check out our joint conference webpage GREEN DIGITALIZATION and learn more about the programs. And sign up! 

New CITIES-related project looks for a solution to reduce CO2 from data centres and server rooms

Although CITIES ends by the end of 2020 after seven years of research, CITIES’ research, findings and thoughts continue through several other projects based on research in CITIES or inspired of CITIES.  A brand new one is Cool-Data; a Grand Solution project supported by Innovation Fund Denmark with DKK 13 million.

Researchers at DTU Compute, DTU Management and DTU Civil Engineering will work with industrial companies to develop a new cooling and storage system for data centres and server rooms, which will be managed through artificial intelligence and reduce energy consumption and thus CO2 emissions.

Dominik Franjo Dominkovic, a postdoc at DTU Compute, is the project manager of Cool-Data. In CITIES he has been working with the technology and methodologies, latest together with one of CITIES partners, EnergyCool, and the electricity and heating company GEV in a demo case in Grindsted in Jutland. See more below

In ‘Cool-Data’ Dominik, EnergyCool and GEV continue the work with the two other DTU departments, and PURIX, Naviair, and Center Denmark. Learn more at the DTU website

Digitalisering i fjernvarmen bidrager til 2030-mål

ENGLISH version: District heating digitalization contributes to 2030 targets

Det sparer penge og CO2, når fjernvarmesektoren styrer temperaturen med data og lokale vejrudsigter i stedet for tegninger af ledningsnettet og mavefornemmelsen. Det viser forskningsprojekter, som CITIES er involveret i. Læs artiklen i DTU-magasinet DYNAMO

1, 7 mio. husstande i Danmark (ca. 64 pct.) bliver opvarmet med fjernvarme, der løber gennem 60.000 kilometer fjernvarmenet. Rejsen fra fjernvarmeværket til radiatorerne tager typisk flere timer, og derfor skal varmebehovet kunne forudsiges.

Man skal ikke skrue mere op for varmeproduktionen end nødvendigt, for det koster penge og er energispild, ligesom temperaturtabet i rørene er større ved højere temperaturer.

Samtidig skal vandet være tilstrækkelig varmt på de såkaldt kritiske punkter i udkanten af ledningsnettet. Så det er en videnskab at styre fjernvarmeproduktionen optimalt.

På DTU Compute arbejder CITIES centerleder professor Henrik Madsen og hans kolleger med datadrevet energi- og temperaturoptimering. Flere forskningsprojekter viser, at digitalisering forbedrer prognosen for varmebehovet markant og derigennem letter vejen til Danmarks 2030-klimamål.

NREL – CITIES Support: Cooperative Research and Development Final Report

The research in CITIES finally comes to an end after seven years of research. Now one of our partners ‘NREL’ points out in a report their support to CITIES with references to four scientific papers and the establishment of Center Denmark.

NREL – National Renewable Energy Laboratory National Renewable Energy Laboratory – operated by Alliance for Sustainable Energy for the U.S. Department of Energy (DOE).

Energy System Integration
Modeling, simulation and analysis of integrated energy system and evaluate the use of the Energy Systems Integration Facility (ESIF).

The ESIF is the first US research facility that can conduct integrated megawatt-scale research, development, and demonstration of the components and strategies needed to safely and seamlessly integrate clean energy technologies into energy systems infrastructure and utility operations at the speed and scale required to meet national goals.

In order to achieve the ambitious goal of a fully renewable Danish energy system, an overhaul of the operation, monitoring and planning of the entire energy system is necessary.

By moving from the traditional view of the power, heating, cooling, water and other systems as completely separate, centralized and mostly radial, to recognizing the significant opportunities for efficiency and emission reduction brought about by allowing these systems to fully integrate and interact with one another.

Integration of previously distinct energy systems allows for flexibility throughout the system, so that society’s needs for energy can be met while considering the fluctuating nature of many renewable energy resources.

Integrated Information and Communications Technology (ICT) powered systems offer the possibility of intermediate conversion and storage of energy in forms including power [sub-daily], heat (including the district heating network) [daily] and gas [seasonal], providing an essential service to balance the variations in wind and other forms of renewable energy production and ensure the security of energy supply. The high density and diversity of energy use and networks within a city environment, coupled with the expressed desire to achieve sustainability within cities maims them an ideal framework for this research activity.

“Energy System Integration: Defining and Describing the Value Proposition”, M. O’Malley, B. Kroposki, B. Hannegan, H. Madsen, M. Andersson, W. D’haeseleer, M. McGranaghan, C. Dent, G. Strbac, S. Baskaran, M. Rinker, NREL Technical Report NREL/TP-5D00-66616, June 2016,

Demand response
Additional results in the project focused on examining demand response (DR) as a way to increase flexibility in the operation of energy systems. DR proponents widely laud its prospective benefits, which include enabling higher penetrations of variable renewable generation at lower cost than alternative storage technologies, and improving economic efficiency.

In practice, DR from the commercial and residential sectors is largely an emerging, not a mature, resource, and its actual costs and benefits need to be studied to determine promising combinations of physical DR resource, enabling controls and communications, power system characteristics, regulatory environments, market structures, and business models.

The work during this project focused on the enablement of such analysis from the production cost modeling perspective. In particular, a bottom-up methodology for modeling load-shifting DR in production cost models was developed.

The resulting model is sufficiently detailed to reflect the physical characteristics and constraints of the underlying flexible load, and includes the possibility of capturing diurnal and seasonal variations in the resource.

“On the Inclusion of Energy- Shifting Demand Response in Production Cost Models: Methodology and a Case Study”, N. O’Connell, E. Hale, I. Doebber, J. Jorgenson, NREL Technical Report, NREL/TP-6A20-64465, July 2015,

Transactive Energy
The project also examined the concept of “Transactive Energy” (TE) and conducted significant work simulating transactive control in distribution systems. NREL, University of Colorado, South Dakota State and DTU performed their simulation using the Integrated Energy Systems Model (IESM) co-simulation platform.

The team implemented network-aware TE controls in the IESM co-simulation framework that manages distribution feeder voltages based on real-time optimal power flow. This is one part of a multi-timescale TE control approach that NREL is developing to reduce costs for both balancing power supply and demand and managing distribution feeder voltages.

This multi-timescale TE approach uses a price signal based on two components: an energy price based on wholesale prices and bids by participating DERs that adjusts on a 5-15 min market cycle, plus an incentive signal overlay for fast grid services, updated every 1-10s. For the TE Challenge, NREL simulated only the calculation of the incentive signals for voltage regulation services and used the time-of-use (TOU) price as the energy price.

More extensive analysis using a longer test period is required to determine appropriate levels of compensation for PV curtailment and reactive power support that will ensure fair compensation to houses that provide voltage regulation services.

“NIST Transactive Energy Modeling and Simulation Challenge Phase II Final Report” D. Holmberg, M. Burns, S. Bushby, A. Gopstein. T. McDermott, Y. Tang, Q. Huang, A. Pratt, M. Ruth, F. Ding, Y. Bichpuriya, N. Rajagopal, M. Ilic, R. Jaddivada, H. Neema, NIST Special Publication 1900-603,

Integrated energy planning with variable renewable energy
The research also examined the integration of a very large share of variable renewable energy sources into the energy system.

To do this, an integrated energy planning approach was used, including ice storage in the cooling sector, a smart charging option in the transport sector, and an excess capacity of reverse osmosis technology that was utilized in order to provide flexibility to the energy system. A unit commitment and economic dispatch tool (PLEXOS) was used, and the model was run with both 5 min and 1 h time resolutions.

The case study was carried out for a typical Caribbean island nation, based on data derived from measured data from Aruba. The results showed that 78.1% of the final electricity demand in 2020 was met by variable renewable energy sources, having 1.0% of curtailed energy in the energy system.

The total economic cost of the modelled energy system was similar to the current energy system, dominated by fossil fuel imports. The results are relevant to many populated islands and island nations.

“Integrated Energy Planning with a High Share of Variable Renewable Energy Sources for a Caribbean Island”, D. Dominkovic, G. Stark, B. Hodge, and A, Pederson, Energies 2018, 11(9), 2193,

Center Denmark
Finally, NREL points out the support for the establishment and design of Center Denmark, the new Danish national digitalization hub for data-intelligent and integrated energy systems.  

NREL mentioned Center Denmark has been heavily influenced by the research at NREL and their research facility;  Energy Systems Integration Facility (ESIF). See above.

Download the report
The report ‘NREL CITIES Support: Cooperative Research and Development Final Report‘ is available at no cost from the National Renewable Energy Laboratory (NREL).