Groningen Energy neutral in 2025? Opportunities for an energy neutral built environment in the City of Groningen

Abstract

The use of fossil energy sources and the accompanying emissions are assumed to cause climate change. Initiatives are being taken to avert climate change from occurring. The city of Groningen even has the ambition to become “energy neutral” in 2025 to help reaching this goal. Energy neutral in this context means reducing the amount of CO2 emitted as much as possible. The rate of becoming energy neutral can than be measured by the rate of reducing the amount of CO2 emitted. In the city of Groningen approximately 50% of the CO2 emissions are generated within the built environment. According to the city of Groningen in this sector a significant emission reduction can be realized by applying energy saving measures on buildings. It is therefore investigated in this research how much these energy saving measures actually contribute to reaching an energy neutral built environment. First it was investigated what the energy demand and accompanying emissions were for the built environment in the city of Groningen for the year 2000. Next these values were extrapolated to the year 2025 by making use of the Dutch GE and SE scenarios. These two scenarios calculated the energy need and emissions for the Netherlands until 2025. For this research these scenarios were adjusted to determine the specific situation for the city of Groningen in 2025 called the reference scenario. To do so the built environment was subdivided into the domestic and the services sector. The so-called reference scenario for the city of Groningen was modelled apart for the domestic and the services sector in respectively MERLiN (Modelling Energy Resources Limitations in Neighbourhoods) and an Excel model. Within these models three city quarters in the city of Groningen were modelled until 2025 to be able to show the differences in impacts of energy saving options on different types of city quarters. These city quarters are: the City Center, with relatively small and old houses, Corpus den Hoorn with larger and newer houses and Meerstad (first partial plan) with relatively large houses that still have to be built between 2000 and 2025. Then it was investigated what the impact of applying several energy saving measures on buildings meant for the emissions generated in the domestic sector in Groningen as a whole and for the three specific city quarters. Within MERLiN therefore three scenarios were created in which, compared to the standard situation in 2025, respectively low extra effort, medium extra effort and high extra effort to reduce the energy demand were assumed. The amount of effort is translated into the amount of energy saving measures and the efficiency of the measures that were applied on the buildings. For all the three scenarios the gas demand was reduced significantly compared to the standard situation in 2025, yet the electricity demand was hardly affected at all. The research areas with a high fraction of existing buildings showed a relatively high reduction of gas demand with relatively little extra energy saving measures, while the areas with a high fraction of new to build buildings showed a higher reduction in gas demand with a relatively large amount of extra energy saving measures. It can also be seen that in larger houses there is on average a higher electricity demand as in smaller houses. The final reductions in energy demand and emissions for the different scenarios calculated for the domestic sector in MERLiN were also used in the Excel model to calculate the reduction potential for the services sector and with that for the built environment as a whole. When comparing these results for 2025 with the situation in 2000 this resulted in the worst case in an increase of emissions of 16%, yet in the best case in a decrease of emissions of 25%. Applying energy saving measures on buildings therefore seems to have a highly varying but on average only limited contribution to reducing emissions in the built environment. When investigating the results generated by MERLiN, it can be seen the applied energy saving measures mainly reduce the gas demanded for space heating. Therefore to reach an energy neutral built environment other measures than the measures applied on the level of a building discussed in this research, should be applied to also reduce the electricity demand. These measures could for example be applying other electricity saving technical measures, behavioral changes or making use of more sustainable energy sources. Within the existing built environment this is supposed to realize significant emission reductions. In the new to build buildings even more reduction can potentially be realized with relatively little effort, since during construction it can be taken into account which energy saving measures have to be applied. Special attention should therefore be given to this relatively large fraction of buildings by the city of Groningen to construct them as energy neutral as possible. What can be concluded from this research is that a significant amount of effort is required to realize an energy neutral built environment. In the case of Groningen 50% of the emissions are generated within this sector, therefore even more effort is required to realize a totally energy neutral city. Trying to become energy neutral and with that trying to prevent climate change is therefore easier said then done. A paradigm shift in thinking and acting, starting from today, seems imperative when intending to reach this goal.