Digitalization

District heating utilities have long used consumption data and prognoses to plan their production and meet the local heat demand. But to achieve more operational goals, the use of large amounts of existing data has been limited. The HEAT 4.0 project has therefore set this on the agenda. It has successfully demonstrated new methods and an open digital platform where IT and OT[1]can meet in new harmonies.

By Alfred Heller – HEAT 4.0 Project Manager NIRAS,
Eva Lange Rasmussen – Communication consultant NIRAS,
Per Sieverts Nielsen – Senior Researcher, Ph.D. DTU,
Henrik Madsen – Professor, Head of Department of Applied Mathematics and Computer Science DTU Compute

The main objective of the implementation of digitalization was to create environmental, operational, and economic efficiency for district heating companies. 

HEAT 4.0 addressed the digital needs of the entire sector, from the production site to distribution to energy consumption – and it has created synergy between the design, operation, maintenance, and supply of district heating on a new and unprecedented digital level. The invented solution is called Cross System Optimization (CSO) and has been created in close collaboration between the project’s 16 partners: component suppliers, researchers, district heating companies, and software developers.  
HEAT 4.0 started in 2019 and was a 3-year project supported by Innovation Fund Denmark.

Software customization

In the project, three district heating companies were involved: Hillerød Utility, Brønderslev Utility, and TREFOR, who each demanded that the project add genuine efficiency improvements to the district heating system, from which all heating companies could benefit. 

The standard digital procedure is that each district heating company installs and integrates the software systems they would like to use in their own district heating operation – without setting requirements to communicate across the different software solutions and services. The first step in the HEAT 4.0 project was to find secure methods for the OT systems to be opened up to their surroundings in a controlled way and thus be able to both send and simultaneously receive data from other surrounding IT systems. In the development process of this new IT architecture, strict requirements were set for cyber security to protect data and prevent possible hacker attacks. 

It was necessary to standardize the IT language used to improve operators’ performance and control capabilities. Here, the recommendation was to use OPC-UA as a standard protocol for data exchange, which has been developed within Industry 4.0 and has inspired the name of the current project. In addition, HEAT 4.0 recommends the use of REST-API interfaces for the data exchange between software packages. 

First, a so-called peer-to-peer (p2p) solution was developed for communication purposes, which denotes the agile and flexible communicative IT structure without a centralized server. But the project’s ambition was higher – and work was subsequently done to create a ‘common data platform.’ The platform aimed to ensure data quality by, for example, validating data, troubleshooting missing data, and resampling data at the required sampling rates. In addition, the platform’s purpose was to enable the district heating plants to select and replace several different digital services/software systems and connect them via plug-n-play technologies through common data interfaces.

At the time of writing, work is continuing to develop such a commercial cloud, of which the project partner ‘Center Denmark’ is in charge. The cloud solution will save district heating companies many hours of integration, make usage data much more intelligent, provide freedom of software choice to operators, and simultaneously comply with the high requirements for IT security and privacy rules (GDPR), of course.

Figure: The development of IT architecture in the District Heating system. 

Prospect to many efficiency and financial savings 

The goal of the entire HEAT 4.0 project was to demonstrate savings of heat losses in the pipe network of 1-2% through digitization. But research results during the project process showed that the saving potentials were much higher for the already efficiently managed District Heating plants like the Danish. The project has documented the following possible savings from data-driven optimization of the district heating system:

• Significant savings using improved weather and temperature forecasts and heat consumption predictions
• 10 – 30% savings from predictive control of heat pumps
• 5 – 20%savings by integrating forecasting into the buildings’ smart management systems (smart house)
• Up to 20% savings by using the grid and houses for flexible energy storage
• 10 – 40% improvements in electricity and heat load forecasts
• Up to 20% savings through optimal operation and bidding, i.e., purchase of energy at the most advantageous times

The above results are from research-based feedback from the partners involved, each representing its part of the holistic district heating system: production, distribution, and consumption. The results testify to the fact that through digitalization, it is possible to create valuable synergy and efficiency for the entire district heating system through intelligent use and interconnection of data. 

Positive results

At the participating HEAT 4.0 district heating plants, the described cross-cutting optimization (CSO) solution and some of the above savings options were tested. Thus, measurements were carried out both before the implementation of HEAT 4.0 (heating season 1: 2019-2020), the year after various software solutions were installed (heating season 2: 2020-2021), and again in heat season 3: 2021-2022. The purpose was to prove savings between seasons 2 and 3.