RAPIDH – Renewable and Affordable Process-Integrated District Heating

The RAPIDH project will develop software and methods for model-based analyses that will increase energy efficiency, reduce carbon emissions, and improve investment decisions for the process industry (PI). The focus is on integrating the district heating (DH) and industrial sectors and how district heating can be part of a carbon-neutral supply of process heat.

Why District Heating is Critical for Decarbonizing the Process Industry  

Today, industrial processes are typically driven by fossil fuels and PI companies struggle to find solutions that are both affordable, improve energy and cost efficiency, and reduce carbon emissions. The process energy sector requests new and carbon-neutral energy sources, and carbon-neutral heat supplied through the DH infrastructure is an attractive – but largely unexploited and unknown – resource. Combinations of DH and local high-temperature heat pumps will enable process energy solutions utilising DH-based carbon-neutral energy sources such as: 

• Deep geothermal heat, ambient air, and water (sea, rivers, lakes)  
• Excess heat from other industrial companies, Power-to-X facilities, and datacentres 

The RAPIDH Solution is based on explicit demands from companies in the PI sector, experts from DH utilities, technical consultants, as well as equipment suppliers in the DH and energy sectors, and it builds on other R&D projects.

Project idea

The RAPIDH project bridges this gap by creating tools to analyze and optimise the integration of district heating into industrial operations. To enhance this process, the well-established software model energyPRO – used for design, optimisation, and business cases in the DH sector – will be developed to support the same in the process industry sector. The idea is to create the new module for the PI sector and then validate it by testing it with 11 PI and DH case owners.  

Expected outcome 

RAPIDH aims to deliver a standardised RAPIDH Solution, enabling rapid and valid techno-economical investment decisions supporting:

• Replacement of fossil process energy with tailormade combinations of energy from district heating, electricity, biogas, and biomass in the most cost and energy efficient way.
• More accurate calculations of the feasibility of using district heating to supply heat to industrial processes on both the demand (PI) and supply (DH) side.

The new RAPIDH Solution consist of a new energyPRO RAPIDH module and a method to support planning and investment decisions. The new software module is needed for the data and mapping of the industrial processes, the optimisation, the handling of combined technical solutions, and quantifying economic and carbon-emission reductions across both PI and DH sectors.

This will support technical consultants to provide reliable and reproducible feasibility studies and business cases, reducing risks for industrial companies and DH operators alike. Planning and investments decisions will benefit from improved, model-based analyses that include benefits from sector integration. Examples of expected applications are:

• Feasibility analyses and business cases to support investment decisions reducing carbon emissions from industrial processes. The technical solutions encompass the whole set of processes, and the economic assessments includes impact from processes and energy supplies.
• Integration of industrial heat consumption in planning and development of new or existing DH systems.
  • For DH companies, the new services will provide the necessary knowledge of how much process energy they can supply at what time and at what price – depending on the technical solution. This is the foundation for making an agreement with a local industry company to connect to the DH grid. The same thing goes for heat flow in the other direction – assessing and using surplus heat from industry and other sources to be reused via the DH system.
  • For municipalities, the new services will allow them to improve their climate and energy planning. Being able to include the effects of sector integration and plan more holistically. This also includes the ability to use excess heat from sources such as hydrogen production/PtX to supply process heat via the DH grid.
  • For energy agencies and other national entities, the accumulated effects of the new services combined with energy system analyses at national level will provide new insights and quantify impacts. This will support sound political decisions on e.g. framework conditions, subsidy programs, and strategic support to boost implementation.
• Master planning and step-by-step implementation of decisions. A complete transformation of a production line, making a DH system carbon neutral, or developing an energy plan for the whole municipality can only be implemented step-by-step. By using the new RAPIDH Solution to develop a guiding master plan, each step can be designed and scheduled in accordance with a trustworthy, overall plan.

Zooming in on the benefits to DH utilities 

From the DH sector’s viewpoint, industrial processes are very interesting. They have a high and predictable heat demand, and consumption is spread out more equally during the year than the heating demand from buildings (space heating). Supplying heat for the local processing industry could benefit the DH company in at least four ways.

1. Lower the average heat production price, which reduces the variable (consumption-based) part of the heating bill.
2. More customers will pay for staff, existing units, and the grid, which will reduce the fixed part of everyone’s heating bill.
3. Increase local visibility and acceptance by helping local businesses and keeping jobs in the area.
4. The additional heat demand can accelerate investments in heat storage and sustainable heat production.

This will only happen if both the PI and the DH company make the necessary decisions, which brings us back to the need for a better simulation model and efficient methods for technical consultants.

Figure: Simplified illustration. On the left, low- or zero-emission heating is supplied by base load production (low heat price) and peak load production (higher heat price). On the right, the DH system now also supplies process energy to local companies. Production runs all year and increases heat demand equally in summer and winter (right). This improves efficiency and lowers costs of the whole system. One of the reasons being a higher utilization on the investment-heavy base load units (dark green area).

Energy efficiency requires sector integration 

Some industrial companies leave behind potential heat in terms of excess heat that cannot be re-used in other processes. The new energyPRO RAPIDH module will be able to clarify and present the opportunities for the district heating company to use excess heat or to supply process heat. In this way, decision making of future projects will be clearer and make it easier for industrial companies and DH companies to collaborate and fasten the transition from fossil fuels into carbon-neutral energy. Utilizing excess heat in local district heating networks can be a stepping-stone towards achieving carbon neutrality as argued in Heat Plan Denmark 2021, where excess heat plays an important role for having an energy and cost-efficient future heat supply. Both the electricity and DH systems are on a journey toward carbon neutrality and better sector integration using a step by-step approach, as described e.g. by Lars Gullev in an article published in Hot|Cool issue no. 6/2023 [source: p. 3]. Integration via DH is necessary to connect the vast amounts of excess heat production with the industrial need for process heat.

Figure: The business sector needs carbon-neutral alternatives to replace fossil process heat. The excess heat from PtX, datacentres or other industrial companies cannot be used directly in industrial processes (top). But it can be harnessed using integration with a district heating system (bottom). Copy of figure from the report “Power-to-X and District heating” published by the Danish DH association, COWI, and TVIS and authored by now DBDH-employee Hanne Kortegaard Støchkel.