Open Access

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.

Green hydrogen and synthetic fuels are increasingly recognized as a key strategic element for the progress of the global energy transition. The Middle East and North Africa (MENA) region, with its large wind and solar potential, is well positioned to generate renewable energy at low cost for the production of green hydrogen and synthetic fuels, and is therefore considered as a potential future producer and exporter. Yet, while solar and wind energy potentials are essential, other factors are expected to play an equally important role for the development of green hydrogen and synthetic fuels (export) sectors. This includes, in particular, adequate industrial capacities and infrastructures. These preconditions vary from country to country, and while they have been often mentioned in the discussion on green hydrogen exports, they have only been examined to a limited extent. This paper employs a case study approach to assess the existing infrastructural and industrial conditions in Jordan, Morocco, and Oman for the development of a green hydrogen and downstream synthetic fuel (export) sector.

Nigeria is Africa's top cement producer and could be on course to be one of the top producers globally. The goal of this study is to identify and critically examine the pathways available to Nigeria to meet its decarbonisation goals in the cement sector. Based on a literature review, the study assesses demand drivers and decarbonisation potentials for the sector. It then presents two different quantitative pathways for growth in production of cement by 2050, and three different pathways for decarbonisation of the sector. Using published data and a scenario analysis tool, the study calculates how the sector's emissions might evolve under each of these pathways. The results indicate that, in the most ambitious scenario, emissions from the sector can plateau by the late 2030s, resulting in an overall increase of 21% by 2050 (compared to 2015 levels). Achieving this scenario is necessary in order to put the sector on a path to net zero emissions beyond 2050. The scenario is driven by reductions in both energy-related and process emissions, as well as a small share of carbon capture and storage and demand management. A moderately ambitious scenario that relies mostly on savings on energy-related emissions results in an 84% increase in emissions by 2050. Finally, the Business-as-Usual scenario results in an almost tripling of emissions by 2050. The results indicate a strong potential for policies to drive improvements in energy efficiency and clinker-to-cement ratio. Critical areas of uncertainty within the assumptions include the production rates (including the evolution of the export market) and the fuel mix.

Community-based approaches to natural resource management are being discussed and experienced as promising ways for pursuing ecological conservation and socio-economic development simultaneously. However, the multiplicity of levels, scales, objectives and actors that are involved in sustainability transformations tends to be challenging for such bottom-up approaches. Collaborative and polycentric governance schemes are proposed for dealing with those challenges. What has not been fully explored is how knowledge from local contexts of community-based initiatives can be diffused to influence practices on higher levels and/or in other local contexts. This study explores how theoretical advances in the diffusion of grassroots innovation can contribute to understanding and supporting the diffusion of knowledge and practices from community-based initiatives and proposes a transdisciplinary approach to diffusion. For that aim, we develop an analytical perspective on the diffusion of grassroots innovations that takes into consideration the multiplicity of actors, levels and scales, the different qualities/types of knowledge and practices, as well as their respective contributions. We focus on the multiplicity and situatedness of cognitive frames and conceptualize the diffusion of grassroots innovations as a transdisciplinary process. In this way three different diffusion pathways are derived in which the knowledge and practices of grassroots initiatives can be processed in order to promote their (re)interpretation and (re)application in situations and by actors that do not share the cognitive frame and the local context of the originating grassroots initiative. The application of the developed approach is illustrated through transdisciplinary research for the diffusion of sustainable family farming innovations in Colombia. This conceptualization accounts for the emergence of multiplicity as an outcome of diffusion by emphasizing difference as a core resource in building sustainable futures.

Innovative digital technologies open up new opportun­ ities for small and medium-sized enterprises (SMEs) to improve energy efficiency and energy management behavior. The question is: How far will SMEs be capable of profiting from the benefits of these new technologies? Using technology screening, this study identifies smart metering and mobile energy monitoring as digital technologies best addressing SMEs' specific demands. In addition, potentials and limitations of the technologies are investigated in two qualitative in-depth field trials. Barriers to adopting digitally enabled energy management practices are examined. The results indicate that visualising energy data enables SMEs to pursue new energy management practices for reducing energy consumption and costs (such as peak load analysis). SMEs need extensive guidance to identify and pursue these strategies. In conclusion, an exploratory adoption model for digitally enabled energy management practices is developed. Hypotheses for future experimental studies and policy implications are derived.

Decarbonizing global steel production requires a fundamental transformation. A sectoral climate club, which goes beyond tariffs and involves deep transnational cooperation, can facilitate this transformation by addressing technical, economic and political uncertainties.

With the move to a hydrogen-based primary steel production envisioned for the near future in Europe, existing regional industrial clusters loose major assets. Such a restructuring of industries may result in a new geographical distribution of the steel industry and also to another quality of vertical integration at sites. Both implications could turn out as drivers or barriers to invest in new technologies and are thus important in respect to vertical integration of sites and to regional policy. This paper describes an approach to model production stock invest for the steel industries in North-Western Europe. Current spatial structures are reproduced with capacity, technical and energy efficiency data on the level of single facilities like blast furnaces. With the model developed both investments in specific technologies and at specific production sites can be modelled. The model is used to simulate different possible future scenarios. The case with a clear move to hydrogen-based production is compared to a reference scenario without technological shift. The scenarios show that existing trends like movement of production to the coast may be accelerated by the new technology but that sites in the hinterland can also adapt to a hydrogen economy. Possible effects of business cycles or a circular economy on regional value chains are explored with a Monte-Carlo analysis.

Although smart energy technologies (SETs) can fulfill multiple tasks in increasingly decarbonized and digitalized energy systems, market diffusion is still limited. This study investigates which beliefs influence consumers' intention to adopt two smart-energy offerings, whether the rapid growth of the smart home market will now drive SET adoption, and if consumer-driven diffusion will lead to sustainability potentials being realized. Building on UTAUT2, a new theoretical model is proposed, and a consumer acceptance survey was conducted in Germany (n = 700). Results indicate that a growing smart home market will not increase SET adoption and that "adjustable green defaults" should be introduced.

In Argentina, renewable energies are promoted as a way of decarbonising the electricity mix and providing reliable energy services. The national goal is to generate 20% of electricity from renewable sources by 2025. However, despite significant natural potential, solar photovoltaic still represents only a small share of Argentina's total electricity generation. Although this picture may look bleak, a wide range of market segments relating to decentralised photovoltaic generation in Argentina have developed. The general objective of this study is to examine the dynamics that currently enable or constrain the diffusion of distributed photovoltaic systems in Argentina. By applying the Technical Innovation System (TIS) approach, the aim is to understand which functions of the system are strong/weak and how these are influenced by endogenous/exogenous system strengths and weaknesses. To that end, a mixed method research strategy is applied. The exploratory sequential research design allows first to explore system strengths and weaknesses based on qualitative approaches, and then to further analyse the contextual embeddedness and the level of importance of the identified variables using quantitative survey instruments. Thereby, this study provides an important analytical method that contributes to a more nuanced understanding of the interdependencies of the TIS. The empirical results indicate that system weaknesses are shaped to a large extent by the overall contextual dynamics - such as political instability, energy subsidies and high inflation rates. System strengths relate to both the TIS itself (particularly knowledge development through pilot projects and market formation through provincial and national support programmes), to contextual relationships (linked to the availability of educational institutions that enable the rapid diffusion of knowledge) and to the importance of rural areas as protected spaces for the application of photovoltaic systems. Consequently, the study highlights the challenges to overcome for the broader diffusion of distributed photovoltaic generation.

The target of zero emissions sets a new standard for industry and industrial policy. Industrial policy in the twenty-first century must aim to achieve zero emissions in the energy and emissions intensive industries. Sectors such as steel, cement, and chemicals have so far largely been sheltered from the effects of climate policy. A major shift is needed, from contemporary industrial policy that mainly protects industry to policy strategies that transform the industry. For this purpose, we draw on a wide range of literatures including engineering, economics, policy, governance, and innovation studies to propose a comprehensive industrial policy framework. The policy framework relies on six pillars: directionality, knowledge creation and innovation, creating and reshaping markets, building capacity for governance and change, international coherence, and sensitivity to socio-economic implications of phase-outs. Complementary solutions relying on technological, organizational, and behavioural change must be pursued in parallel and throughout whole value chains. Current policy is limited to supporting mainly some options, e.g. energy efficiency and recycling, with some regions also adopting carbon pricing, although most often exempting the energy and emissions intensive industries. An extended range of options, such as demand management, materials efficiency, and electrification, must also be pursued to reach zero emissions. New policy research and evaluation approaches are needed to support and assess progress as these industries have hitherto largely been overlooked in domestic climate policy as well as international negotiations.

Local implementation projects for sector coupling play an important role in the transformation to a more sustainable energy system. Despite various technical possibilities, there are various barriers to the realisation of local projects. Against this backdrop, we introduce an inter- and transdisciplinary approach to identifying and evaluating different power-to-X paths as well as setting up robust local implementation projects, which account for existing drivers and potential hurdles early on. After developing the approach conceptually, we exemplify our elaborations by applying them to a use case in the German city of Wuppertal. It can be shown that a mix of several interlinked interdisciplinary methods as well as several participatory elements is suitable for triggering a collective, local innovation process. However, the timing and extent of end-user integration remain a balancing act. The paper does not focus on a detailed description of power-to-X (PtX) as a central pillar of the sustainable transformation of the energy system. Rather, it focuses on the innovative methodological approach used to select a suitable use path and design a corresponding business model. The research approach was successfully implemented in the specific case study. However, it also becomes clear that the local-specific consideration entails limitations with regard to the transferability of the research design to other spatial contexts.

Despite Germany's Paris Agreement pledge and coal exit legislation, the political debate around carbon-intensive coal remains heated. Coal power and mining have played an important, yet changing role in the history of German politics. In this paper, we analyze the entire parliamentary debate on coal in the German parliament (Bundestag) from its inception in 1949 to 2019. For this purpose we extract the more than 870,000 parliamentary speeches from all protocols in the history of the Bundestag. We identify the 9167 speeches mentioning coal and apply dynamic topic modeling – an unsupervised machine learning technique that reveals the changing thematic structure of large document collections over time - to analyze changes in parliamentary debates on coal over the past 70 years. The trends in topics and their varying internal structure reflect how energy policy was discussed and legitimized over time: Initially, coal was framed as a driver of economic prosperity and guarantee of energy security. In recent years, the debate evolved towards energy transition, coal phase-out and renewable energy expansion. Germany’s smaller and younger parties, the Greens and the Left Party, debate coal more often in the context of the energy transition and climate protection than other parties. Our results reflect trends in other countries and other fields of energy policy. Methodologically, our study illustrates the potential of and need for computational methods to analyze vast corpora of text and to complement traditional social science methods.

Flexible, system-oriented operating strategies are becoming increasingly important in terms of achieving a climate-neutral energy system transformation. Solid-oxide electrolysis (SOEC) can play an important role in the production of green synthesis gas from renewable energy in the future. Therefore, it is important to investigate the extent to which SOEC can be used flexibly and which feedback effects and constraints must be taken into account. In this study, we derived a specific load profile from an energy turnaround scenario that supports the energy system. SOEC short-stacks were operated and we investigated the impact that the load profile has on electrical stack performance and stack degradation as well as the product gas composition by means of Fourier-transform infrared spectroscopy. The stacks could follow the grid-related requirement profiles of secondary control power and minute reserves very well with transition times of less than two minutes per 25% of relative power. Only short-term disturbances of the H2/CO ratio were observed during transitions due to the adjustment of feed gases. No elevated degradation effects resulting from flexible operation were apparent over 1300 h, although other causes of degradation were present.

Roadmaps for India's energy future foresee that coal power will continue to play a considerable role until the middle of the 21st century. Among other options, carbon capture and storage (CCS) is being considered as a potential technology for decarbonising the power sector. Consequently, it is important to quantify the relative benefits and trade-offs of coal-CCS in comparison to its competing renewable power sources from multiple sustainability perspectives. In this paper, we assess coal-CCS pathways in India up to 2050 and compare coal-CCS with conventional coal, solar PV and wind power sources through an integrated assessment approach coupled with a nexus perspective (energy-cost-climate-water nexus). Our levelized costs assessment reveals that coal-CCS is expensive and significant cost reductions would be needed for CCS to compete in the Indian power market. In addition, although carbon pricing could make coal-CCS competitive in relation to conventional coal power plants, it cannot influence the lack of competitiveness of coal-CCS with respect to renewables. From a climate perspective, CCS can significantly reduce the life cycle GHG emissions of conventional coal power plants, but renewables are better positioned than coal-CCS if the goal is ambitious climate change mitigation. Our water footprint assessment reveals that coal-CCS consumes an enormous volume of water resources in comparison to conventional coal and, in particular, to renewables. To conclude, our findings highlight that coal-CCS not only suffers from typical new technology development related challenges - such as a lack of technical potential assessments and necessary support infrastructure, and high costs - but also from severe resource constraints (especially water) in an era of global warming and the competition from outperforming renewable power sources. Our study, therefore, adds a considerable level of techno-economic and environmental nexus specificity to the current debate about coal-based large-scale CCS and the low carbon energy transition in emerging and developing economies in the Global South.

Water and energy are two pivotal areas for future sustainable development, with complex linkages existing between the two sectors. These linkages require special attention in the context of the energy transition. Against this background, this paper analyses the role of water availability in the development of solar thermal and photovoltaic power plants for the case of the Draa Valley in southern Morocco. Located in a semi-arid to arid mountainous area, the Drâa Valley faces high water stress - a situation expected to worsen due to climate change. At the same time, the region has one of the greatest potentials for solar energy in the world. To examine whether limited water availability could accelerate or delay the implementation of solar thermal and photovoltaic power plants, this paper compares regional water availability and demand in the Draa Valley for different scenarios, paying particular attention to potential socio-economic development pathways. The Water Evaluation and Planning System software is applied to allocate the water resources in the study region. The water supply is modelled under the Representative Concentration Pathway 8.5 climate scenario, while the water demand for the Drâa Valley is modelled for a combination of three socio-economic and two energy scenarios. The climate scenario describes a significant decrease in water availability by 2050, while the socio-economic and energy scenarios show an increase in water demand. The results demonstrate that during a sequence of dry years the reservoirs water availability is reduced and shortages in water supply can result in high levels of unmet demand. If this situation occurs, oasis farming, water for drinking and energy production could compete directly with each other for water resources. The energy scenarios indicate that the use of dry cooling technologies in concentrated solar power and photovoltaic hybrid systems could be one option for reducing competition for the scarce water resources in the region. However, given that energy generation accounts for only a small share of the regional water demand, the results also suggest that socio-economic demand reduction, especially in the agricultural sector, for example by reducing the cultivated area, will most likely become necessary.

The paper provides an integrated assessment of environmental and socio-economic effects arising from final consumption of food products by European households. Direct and indirect effects accumulated along the global supply chain are assessed by applying environmentally extended input-output analysis (EE-IOA). EXIOBASE 3.4 database is used as a source of detailed information on environmental pressures and world input-output transactions of intermediate and final goods and services. An original methodology to produce detailed allocation matrices to link IO data with household expenditure data is presented and applied. The results show a relative decoupling between environmental pressures and consumption over time and shows that European food consumption generates relatively less environmental pressures outside Europe (due to imports) than average European consumption. A methodological framework is defined to analyze the main driving forces by means of a structural decomposition analysis (SDA). The results of the SDA highlight that while technological developments and changes in the mix of consumed food products result in reductions in environmental pressures, this is offset by growth in consumption. The results highlight the importance of directing specific research and policy efforts towards food consumption to support the transition to a more sustainable food system in line with the objectives of the EU Farm to Fork Strategy.

The mass roll out of solar PV across the Global South has enabled electricity access for millions of people. In the right context, Small Wind Turbines (SWTs) can be complementary, offering the potential to generate at times of low solar resource (night, monsoon season, winter, etc.) and increasing the proportion of the total energy system that can be manufactured locally. However, many contextual factors critically affect the viability of the technology, such as the extreme variability in the wind resource itself and the local availability of technical support. Therefore, performing a detailed market analysis in each new context is much more important. The Wind Empowerment Market Assessment Methodology (WEMAM) is a multi-scalar, transdisciplinary methodology for identifying the niche contexts where small wind can make a valuable contribution to rural electrification. This paper aims to inform the development of WEMAM with a critical review of existing market assessment methodologies. By breaking down WEMAM into its component parts, reflecting upon its practical applications to date and drawing upon insights from the literature, opportunities where it could continue to evolve are highlighted. Key opportunities include shifting the focus towards development outcomes; creating community archetypes; localised studies in high potential regions; scenario modelling and MCDA ranking of proposed interventions; participatory market mapping; and applying socio-technical transitions theory to understand how the small wind niche can break through into the mainstream.

Integrated assessment models (IAMs) are commonly used by decision makers in order to derive climate policies. IAMs are currently based on climate-economics interactions, whereas the role of social system has been highlighted to be of prime importance on the implementation of climate policies. Beyond existing IAMs, we argue that it is therefore urgent to increase efforts in the integration of social processes within IAMs. For achieving such a challenge, we present some promising avenues of research based on the social branches of economics. We finally present the potential implications yielded by such social IAMs.

This theory note develops a theoretical approach which integrates the negative spillovers that international institutions often impose on each other into our thinking about their normative legitimacy. Our approach draws on the political philosophy of Rainer Forst which revolves around the right to justification. It suggests that regime complexes facilitate the breakup of institution-specific orders of justification by prompting invested actors to justify negative spillovers vis-a-vis each other. Thus, regime complexes enable more encompassing justifications of negative spillovers than stand-alone international institutions. Against this backdrop, we submit that the proliferation of regime complexes represents normative progress in global governance.

Participatory modeling - the involvement of stakeholders in the modeling process - can support various objectives, such as stimulating learning processes or promoting mutual understanding of stakeholders. Participatory modeling approaches could therefore be useful for the governance of transitions, but a systematic account of potential application areas of participatory modeling methods in transition governance is still lacking. This article addresses this gap by providing a review of participatory modeling methods and linking them to phases and objectives of transition governance. We reviewed participatory modeling studies in transition research and related fields of social-ecological modeling, integrated assessment and environmental management. We find that participatory modeling methods are mostly used for participatory visioning and goal setting as well as for interactive strategy development. The review shows the potential for extending the application of participatory modeling methods to additional phases of transition governance and for the exchange of experiences between research fields.

A significant reduction in greenhouse gas emissions will be necessary in the coming decades to enable the global community to avoid the most dangerous consequences of man-made global warming. This fact is reflected in Germany's 7th Federal Energy Research Program (EFP), which was adopted in 2018. Direct Air Capture (DAC) technologies used to absorb carbon dioxide (CO2) from the atmosphere comprise one way to achieve these reductions in greenhouse gases. DAC has been identified as a technology (group) for which there are still major technology gaps. The intention of this article is to explore the potential role of DAC for the EFP by using a multi-dimensional analysis showing the technology's possible contributions to the German government's energy and climate policy goals and to German industry's global reputation in the field of modern energy technologies, as well as the possibilities of integrating DAC into the existing energy system. The results show that the future role of DAC is affected by a variety of uncertainty factors. The technology is still in an early stage of development and has yet to prove its large-scale technical feasibility, as well as its economic viability. The results of the multi-dimensional evaluation, as well as the need for further technological development, integrated assessment, and systems-level analyses, justify the inclusion of DAC technology in national energy research programs like the EFP.

In recent years, most countries in the Middle East and North Africa (MENA), including Jordan, Morocco and Tunisia, have rolled out national policies with the goal of decarbonising their economies. Energy policy goals in these countries have been characterised by expanding the deployment of renewable energy technologies in the electricity mix in the medium term (i.e., until 2030). This tacitly signals a transformation of socio-technical systems by 2030 and beyond. Nevertheless, how these policy objectives actually translate into future scenarios that can also take into account a long-term perspective up to 2050 and correspond to local preferences remains largely understudied. This paper aims to fill this gap by identifying the most widely preferred long-term electricity scenarios for Jordan, Morocco and Tunisia. During a series of two-day workshops (one in each country), the research team, along with local stakeholders, adopted a participatory approach to develop multiple 2050 electricity scenarios, which enabled electricity pathways to be modelled using Renewable Energy Pathway Simulation System GIS (renpassG!S). We subsequently used the Analytical Hierarchy Process (AHP) within a Multi-Criteria Analysis (MCA) to capture local preferences. The empirical findings show that local stakeholders in all three countries preferred electricity scenarios mainly or even exclusively based on renewables. The findings demonstrate a clear preference for renewable energies and show that useful insights can be generated using participatory approaches to energy planning.

Many countries are increasingly investing in renewable energy technologies to meet growing energy demands and increase the security of their energy supply. This development is also evident in the Middle East and North Africa (MENA) region, where renewable energy targets and policies have evolved rapidly in recent years. There is a steady increase in both the number of planned and implemented solar photovoltaic (PV) but also of solar thermal projects in form of Concentrating Solar Power (CSP) plants. Many of these installations are designed as large utility-scale systems. Despite the fact that these types of large-scale projects can have significant effects on local communities and their livelihoods, the existing research into the social impacts of such large-scale renewable energy infrastructures at local level is limited. However, assessing and managing these impacts is becoming increasingly important to reduce risks to both the affected communities and to the project and businesses activities. In order to provide more robust evidence on the local effects, this research study reviews the social impacts of large-scale renewable energy infrastructure in the MENA region based on a case study of the NOORo I CSP plant in Ouarzazate, Morocco. Data collected during two empirical field studies, in combination with expert interviews and secondary data analysis, provides detailed evidence on the type and significance of livelihood impacts of the NOORo I CSP plant. The analysis results in a consolidated list of 30 impacts and their significance levels for different stakeholder groups including farmers, young people, women, community representatives and owners of small and medium enterprises. The results show that, overall, the infrastructure development was received positively. The review also indicates that factors identified as having effects on the sustainability of local livelihoods are mainly related to information management and benefit distribution, rather than physical or material aspects.

The Paris Agreement introduces long-term strategies as an instrument to inform progressively more ambitious emission reduction objectives, while holding development goals paramount in the context of national circumstances. In the lead up to the twenty-first Conference of the Parties, the Deep Decarbonization Pathways Project developed mid-century low-emission pathways for 16 countries, based on an innovative pathway design framework. In this Perspective, we describe this framework and show how it can support the development of sectorally and technologically detailed, policy-relevant and country-driven strategies consistent with the Paris Agreement climate goal. We also discuss how this framework can be used to engage stakeholder input and buy-in; design implementation policy packages; reveal necessary technological, financial and institutional enabling conditions; and support global stocktaking and increasing of ambition.

New options are needed to reduce the impact of motor vehicles on climate change and declining fossil fuel resources. Cars which are fueled by hydrogen could be a sustainable method of transportation if suitable technologies can be devised to produce hydrogen in an environmentally benign manner along with the provision of the necessary fueling infrastructure. This paper assesses size, space, and cost requirements of bioreactors as a decentralized option to supply hydrogen powered cars with biohydrogen produced from algae or cyanobacteria on a theoretical basis. Decentralized supply of biohydrogen could help to reduce the problems that hydrogen cars face regarding market penetration. A feasibility study for decentralized biohydrogen production is conducted, taking the quantity of hydrogen which is needed to fuel current hydrogen cars into account. While this technology is, in theory, feasible, sizes, and costs of such reactors are currently too high for widespread adoption. Thus, more R&D is needed to close the gap and to approach marketability.