The global energy system is undergoing a major transition, and in energy planning and decision-making across governments, industry and academia, models play a crucial role. Because of their policy relevance and contested nature, the transparency and open availability of energy models and data are of particular importance. Here we provide a practical how-to guide based on the collective experience of members of the Open Energy Modelling Initiative (Openmod). We discuss key steps to consider when opening code and data, including determining intellectual property ownership, choosing a licence and appropriate modelling languages, distributing code and data, and providing support and building communities. After illustrating these decisions with examples and lessons learned from the community, we conclude that even though individual researchers' choices are important, institutional changes are still also necessary for more openness and transparency in energy research.
Energy sufficiency is one of the three energy sustainability strategies, next to energy efficiency and renewable energies. We analyse to what extent European governments follow this strategy, by conducting a systematic document analysis of all available European National Energy and Climate Plans (NECPs) and Long-Term Strategies (LTSs). We collect and categorise a total of 230 sufficiency-related policy measures, finding large differences between countries. We find most sufficiency policies in the transport sector, when classifying also modal shift policies to change the service quality of transport as sufficiency policies. Types of sufficiency policy instruments vary considerably from sector to sector, for instance the focus on financial incentives and fiscal instruments in the mobility sector, information in the building sector, and financial incentive/tax instruments in cross-sectoral application. Regulatory instruments currently play a minor role for sufficiency policy in the national energy and climate plans of EU member states. Similar to energy efficiency in recent decades, sufficiency still largely referred to as micro-level individual behaviour change or necessary exogenous trends that will need to take place. It is not treated yet as a genuine field of policy action to provide the necessary framework for enabling societal change.
On the pathway to climate neutrality, EU member states are obliged to submit national energy and climate plans (NECPs) with planned policies and measures for decarbonization until 2030 and long-term strategies (LTSs) for further decarbonization until 2050. We analysed the 27 NECPs and 15 LTSs submitted by October 2020 using an interrater method. This paper focuses on energy sufficiency policies and measures in the transport sector.
We found a total of 236 sufficiency policy measures with more than half of them (53 %) in the transport/mobility sector. Additionally, we found 41 measures that address two or more sectors (cross-sectoral measures). From the explicit sufficiency measures within the transport sector, 82 % aim at modal shift. A reduction of transport volumes is much less addressed. Countries plan to use mainly fiscal and economic instruments. Those are in many cases investments in infrastructure of low-carbon transport modes and taxation instruments. Plans on decarbonisation measures are also frequently mentioned. The majority of cross-sectoral measures are carbon taxes or tax reforms, also economic instruments.
On the one hand it is encouraging that Member States strongly emphasize the transport sector in their NECPs and LTSs - at least quantitatively and concerning sufficiency measures - because this sector has been the worst-performing in climate mitigation so far. On the other hand, the measures described seem not sufficient to reach ambitious climate targets, and we doubt that the presented set of policy instruments will get the transport sector on track to mitigate greenhouse gas emissions in the necessary extent.
The ambition to reach climate-neutral energy systems requires profound energy transitions. Various scenario studies exist which present different options to reach that goal. In this paper, key strategies for the transition to climate neutrality in Germany are identified through a meta-analysis of published studies, including scenarios which achieve at least a 95 % greenhouse gas emissions reduction by 2050 compared to 1990. It has been found that a reduction in energy demand, an expansion of domestic wind and solar energy, increased use of biomass as well as the importation of synthetic energy carriers are key strategies in the scenarios, with nuclear energy playing no role, and carbon capture and storage playing a very limited role. Demand-side solutions that reduce the energy demand have a very high potential to diminish the significant challenges of other strategies, which are all facing certain limitations regarding their sustainable potential. The level and and type of demand reductions differ significantly within the scenarios, especially regarding the options of reducing energy service demand.
The war in Ukraine is changing the political landscape at breakneck speed. How should politics and society react to high energy prices and a precarious dependence on fossil fuels imports? Can modern societies get by with much less energy? Energy sufficiency can play an important role in answering these questions. The contributions in this Special topic explore sufficiency as an interdisciplinary research topic for energy modeling, scenarios, and policy.
There is a growing body of scientific evidence supporting sufficiency as an inevitable strategy for mitigating climate change. Despite this, sufficiency plays a minor role in existing climate and energy policies. Following previous work on the National Energy and Climate Plans of EU countries, we conduct a similar content analysis of the recommendations made by citizen assemblies on climate change mitigation in ten European countries and the EU, and compare the results of these studies. Citizen assemblies are representative mini-publics and enjoy a high level of legitimacy.
We identify a total of 860 mitigation policy recommendations in the citizen assemblies' documents, of which 332 (39 %) include sufficiency. Most of the sufficiency policies relate to the mobility sector, the least relate to the buildings sector. Regulatory instruments are the most often proposed means for achieving sufficiency, followed by fiscal and economic instruments. The average approval rate of sufficiency policies is high (93 %), with the highest rates for regulatory policies.
Compared to National Energy and Climate Plans, the citizen assembly recommendations include a significantly higher share of sufficiency policies (factor three to six) with a stronger focus on regulatory policies. Consequently, the recommendations can be interpreted as a call for a sufficiency turn and a regulatory turn in climate mitigation politics. These results suggest that the observed lack of sufficiency in climate policy making is not due to a lack of legitimacy, but rather reflects a reluctance to implement sufficiency policies, the constitution of the policy making process and competing interests.
Sufficiency measures are potentially decisive for the decarbonisation of energy systems but rarely considered in energy policy and modelling. Just as efficiency and renewable energies, the diffusion of demand-side solutions to climate change also relies on policy-making. Our extensive literature review of European and national sufficiency policies fills a gap in existing databases. We present almost 300 policy instruments clustered into relevant categories and publish them as "Energy Sufficiency Policy Database". This paper provides a description of the data clustering, the set-up of the database and an analysis of the policy instruments. A key insight is that sufficiency policy includes much more than bans of products or information tools leaving the responsibility to individuals. It is a comprehensive instrument mix of all policy types, not only enabling sufficiency action, but also reducing currently existing barriers. A policy database can serve as a good starting point for policy recommendations and modelling, further research is needed on barriers and demand-reduction potentials of sufficiency policy instruments.
Demand-side mitigation strategies have been gaining momentum in climate change mitigation research. Still, the impact of different approaches in passenger transport, one of the largest energy demand sectors, remains unclear. We couple a transport simulation model to an energy system optimisation model, both highly disintegrated in order to compare those impacts. Our scenarios are created for the case of Germany in an interdisciplinary, qualitative-quantitative research design, going beyond techno-economic assumptions, and cover Avoid, Shift, and Improve strategies, as well as their combination. The results show that sufficiency - Avoid and Shift strategies - have the same impact as the improvement of propulsion technologies (i.e. efficiency), which is reduction of generation capacities by one quarter. This lowers energy system transformation cost accordingly, but requires different kinds of investments: Sufficiency measures require public investment for high-quality public services, while efficiency measures require individuals to purchase more expensive vehicles at their own cost. These results raise socio-political questions of system design and well-being. However, all strategies are required to unleash the full potential of climate change mitigation.
Where and how do people live? : Modelling the occupation of the German building stock by households
(2024)
Living space needs to be heated in winter and partially cooled in summer and the construction of new buildings requires high amounts of energy and materials. Total living space is increasing, driven by continuously rising average per-capita spaces. The reasons for this are numerous and include the trend to smaller households who live in larger flats, increasing numbers of single-family houses, elderly people remaining in oversized dwellings, e.g. after their children moved out, the unavailability of adequately sized and priced dwellings on the market, and ongoing construction of new buildings even in regions with shrinking or stagnating populations.
Prospective scenarios for a sustainable transition of the building stock thus need to account for these factors, in order to be able to endogenously model impacts of different policy measures and other influencing parameters on the distribution and amount of living space.
This paper presents the approach of the INHABIT model for the German building sector which is currently under development. Based on Socio-Economic Panel (SOEP) data, we model dwelling occupancy, by matching the German population to the dwelling stock.
Historical data shows that dwelling space is increasing for older and wealthier households, even more so in single family homes, and that under-occupation of dwellings concerns exactly these groups: over 50 % of households aged >60 live in under-occupied dwellings.
Finally, we find that also moving rates follow similar patterns and are on average lower for these groups, perpetuating the situation. The proposed model will aim at a simulation of the future of possible occupancy pathways, also as a function of policies that may address prevailing inequalities and inefficiencies in German dwelling occupation.
