A roadmap for St. Gallen’s energy system

What was your approach for evaluating the benefits of an extended district heating system in St. Gallen?

Unlike in the past, where developments were planned, executed, and then the actual impacts of the developments understood, we worked with a digital model. Our model, the Enerpol framework, can simulate the impacts of developments, and the interactions between people and the infrastructure. Thus, we can assess the probable impacts before the developments are actually made. According to our model the extension of the district heating system in St. Gallen will have a positive impact in terms of decreasing the usage of fossil fuels at a reasonable cost. This is an important finding in the context of implementing the new energy policy in Switzerland.

How does the Enerpol framework predict the future?

I should mention that the model is not a crystal ball: Rather than predicting the future, the model allows sketching different future scenarios with a set of assumed boundary conditions to be assessed. Thus, a decision-maker can manage risk through the assessments of the outcomes (including costs, benefits and sensitivities) across the different scenarios. Having said that, we built the entire infrastructure of the city of St. Gallen in our digital model using already existing Geographical Information System data and other related data sources. We included all buildings, roads, gas pipelines, water pipelines, electrical lines, junctions, connections and substations. Moreover, the age of buildings and its systems, for example furnaces – this is important since the older these are, the more likely they are to be changed. But the model goes even further: It includes population demographics, which tells us about the likely behaviour of buildings’ occupants. At the scale of a city, everything is based on individuals and their behaviour.

In a nutshell, what makes the Enerpol framework unique?

First, the Enerpol framework uses a holistic approach: We take into account that the district heating system depends on developments in other areas such as the renovation of buildings. Secondly, the model is agent-based: All individuals are expected to behave in different ways. Thirdly, the scenarios result from dialogues with our partner St. Galler Stadtwerke: This ensures that the outcomes are relevant to our partner.

What are the next steps?

The district heating system is only one piece of a larger puzzle looking at the energy strategy of St. Gallen. In ongoing work, we are looking at different business models for the Stadtwerke that ensure adequate support to manage the charging infrastructure for electric vehicles in line with the city’s targets for market development for electric vehicles. Lastly, it should also be noted that we link this deployment of low-carbon technologies in St. Gallen with changes across Switzerland and Europe. St. Gallen is not an island.