DRI Point-of-View: How to Fast-Track Climate Neutrality with Positive Energy Districts and Local Digital Twins

A member of the DRI team – Pavel Kogut – was a speaker at the online conference Smart Sustainable Cities 2025: Pioneering Novel Frontiers for Green Urban Living. During the ‘digital track’ that took place on 5th March 2025, Pavel presented initial results of the ongoing BIPED project, which is helping Aarhus, Denmark, to reach climate neutrality by building intelligent positive energy districts. Below is a summary of his presentation which you can also view here.

Aarhus climate ambitions have a long history

In 2009, the city hosted a conference that culminated in ‘7 Aarhus statements’ to address climate change beyond Kyoto. In 2022, Aarhus joined the Cities Mission and its network of 112 cities committed to reaching climate neutrality by 2030. In 2024, Aarhus adopted a new climate strategy for 2025-30. The document acknowledges that, although much as been achieved, new solutions need to be tried and tested, otherwise only a third of the current footprint will be offset by the end of the decade.

Aarhus’ annual emissions amount to 1.3 million tonnes CO2e, spread between transport, energy, waste, industrial processes, agriculture, forestry and other land uses. If the business-as-usual trend continues, Aarhus will fall short of reaching the net zero target by 846,000 tonnes CO2e, meaning that two thirds of the footprint will not be neutralized.

Distribution of Aarhus CO2e emissions (000 tonnes)

To prevent this from happening, a variety of initiatives are foreseen in each energy domain, such as opening a new carbon capture facility at the Lisbjerg power plant, increasing the share of geothermal power in the energy mix, electrifying transport, installing more solar panels on the roofs of all building types (public, residential, commercial), and establishing “+ energy” districts, or PEDs.

What are positive energy districts?

PEDs are energy self-sufficient areas that generate energy surplus by producing more energy than they consume in a year. PEDs use the least amount of energy possible (in buildings, this is achieved through deep renovations that yield energy savings of 70-100%). PEDs tap into local renewables, not just wind, solar, and biomass, but also underutilized sources like geothermal and wastewater. Finally, PEDs leverage distributed energy sources like EVs and energy communities to share power with the grid in times of high demand.

PED concept

PED in Brabrand

Through BIPED, Aarhus aims to create its first ever “+ energy” district in Brabrand. It’s one of six districts with a population of about 20,000 inhabitants. Brabrand has a diverse socio-economic texture in terms of residents, many of whom have a migrant background, in terms of the building stock, which includes multi-story apartments, private houses, offices, schools, and sports facilities, and in terms of businesses present (SMEs, industry, services).

Urban regeneration is underway in Brabrand’s Gellerup neighbourhood known for its social housing estates built in the 1960s. Some buildings there are being decommissioned, some demolished, some retrofitted, and some built from scratch to meet decarbonisation targets.

In 2024, Brabrand witnessed the birth of its first energy community called Sol over Brabrand (Sun over Brabrand). Its goal is to install solar panels on residential, commercial and public roofs so that members can trade green electricity and become energy self-sufficient. However, the law currently prohibits energy trade between neighbours. Households can share excess energy to the grid in exchange for credits, but the return value from net metering is not favourable at the moment, something that Sol over Brabrand hopes will change in the future.

Use of LDT to assess solar potential (left) during Sol over Brabrand meeting (right)

In the meantime, the community is preparing a data exercise where not electricity but consumption information will be recorded and shared between 10 households. Combined with data from simulations of solar potential, trial results will be used to assess who will benefit and how (much) from trade if the regulatory landscape changes.

Building a PED intelligently with a Local Digital Twin

Evaluating solar potential of different rooftops is just one example of how the LDT will be used in BIPED. With the energy data obtained from Kredsløb, a local utility, the project will simulate gains for PEDs that could be achieved by expanding district heating and adding more geothermal power to the energy mix. On top of this, scientific methods for energy forecasting, control and optimisation will be developed to find optimal ways of connecting Brabrand to the rest of Aarhus using hierarchies within the energy system.

3D visualisation of Aarhus in BIPED's digital twin 

As transport is one of the major emitters in Aarhus, creating an accurate macroscopic traffic model is a necessary tool for decarbonisation-oriented planning measures. Using floating car data from TomTom, BIPED was able to construct the origin-destination matrix, but only partially since the existing dataset covers about 15-25% of city’s traffic. Additional data acquisition is planned to further improve the model and provide accurate insights into city-wide traffic patterns that can be used as a basis for cross-sectoral ‘what-if’ simulations – for instance, will the grid be able to cope if too many EVs hit the road?

BIPED obtained socio-demographic data from the municipality to ensure its LDT goes beyond energy, traffic and physical structures to reflect Brabran’s ‘soft’ characteristics. Current datasets cover age, gender, citizenship and housing types (social, private, rented). Due to privacy restrictions, this data could not be shared per household. The workaround was to aggregate this data on a 250x250 meter grid, which is still fine for modelling purposes.

If access to employment and income data is also granted, BIPED will be able to assess how the wealth spread might affect adoption of green measures (deep renovations, solar panels, EVs) and behavioural change (variable HVAC use in response to price signals) in Brabrand.

Relevant datasets will be made available in BIPED’s data catalogue which uses DCAT-AP to facilitate metadata search. Other standards used in BIPED’s LDT include OGC API, CityGML, and MIMs.

Conclusion

Much has been achieved in BIPED’s first year, however many barriers still lie ahead (some beyond the project’s control). How to effectively scale “+ energy” concept from building to street to district level? Can data gaps be plugged? Will the regulation allow members of the energy community to eventually trade in green electricity? Addressing what is feasible will be a priority for the coming years. And even if Brabrand doesn’t become “+ energy” by the end of BIPED (2026), the project will have certainly laid a solid foundation on which future efforts can be built to move the needle on PED development, and ultimately make Aarhus climate-neutral by 2030.

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Building a Positive Energy District with a Local Digital Twin in Aarhus.pdf

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