The extent to which post-COVID green recovery measures can accelerate national progress towards net zero remains insufficiently understood, as most existing studies focus on global or regional scales, provide limited sectoral granularity, or report employment effects only in aggregate terms. This study addresses these gaps by assessing the additionality and sufficiency of Greece's National Recovery and Resilience Plan (NRRP) investments and reforms in shaping energy transition pathways and employment opportunities in the power and residential sectors through 2030 and 2050. Using two open-source, bottom-up modelling frameworks, OSeMOSYS and DREEM, the analysis compares NRRP-supported interventions against baseline trajectories aligned with national policy objectives. Direct employment effects are quantified using a technology-specific employment-factor approach linked to future capacity additions and renovation rates. To the authors' knowledge, this is the first modelling assessment of the green recovery measures embedded in Greece's NRRP. The results show that the NRRP can generate meaningful short-term impacts, including modest reductions in fossil-fuel use and emissions, accelerated deployment of variable renewables, storage, and heat pumps, and increased job creation, with operation and maintenance offering the strongest long-term employment prospects. However, its long-term contribution across the sectors examined remains limited, with only minor effects on deep decarbonisation, large-scale renewable expansion, and ambitious renovation pathways. The findings suggest that, while NRRP investments and reforms can stimulate short-term progress, achieving Greece's net-zero objectives will require substantial complementary private investment, stronger implementation capacity, and stable long-term policies capable of turning near-term gains into lasting structural change.

Energy systems are changing as a result of the transition to renewable energy from fossil fuels and the increased deployment and integration of fluctuating renewable energy sources. However, global supply chain challenges, energy crises, and geopolitical conflicts have underlined the need for not only reducing carbon emissions and optimising costs in energy systems but also ensuring energy security and resilience. This adds new dimensions to energy system modelling and to the evaluation of energy system scenarios as an integral part of energy strategy and energy policy development. This study reviews existing energy security and resilience indicators and proposes a decentralisation adjusted diversity index approach for assessing the diversity of energy systems. The proposed diversity index method can be applied alongside different energy system modelling frameworks and can be applied ex post to modelling outputs, as demonstrated by its use with EnergyPLAN and OSeMOSYS for two different national cases, Denmark and Greece. Both cases highlight energy systems transitioning from fossil fuel-based energy systems towards 100% renewable energy systems. Hence the study uses the decentralisation adjusted diversity index to evaluate how the dynamics of energy system diversity changes with the transition to variable renewable energy resources. The phase-out of fossil fuels reduces traditional energy fuel type diversity; however, this is offset by the implementation of geographically dispersed renewable energy sources. This results in an overall increased energy diversity index value for renewable energy systems and thereby increased energy system security and resilience.

National Adaptation Plans (NAPs) are assuming a central role as a policy framework for adaptation, protecting from climate impacts if they thoroughly respond to risks. We present a comprehensive global review of all 60 NAPs submitted to the UNFCCC by developing country parties as of March 1st, 2025. Through the NAP-Good Practices Review Framework, plans are evaluated across the important dimensions of NAP-Coverage and NAP-Consistency. We find that, on average, NAPs contain three-quarters of the elements defining a good NAP—with higher scores for NAP-Consistency than NAP-Coverage. NAPs cover the factbase on vulnerabilities and risks well, followed by policies, goals, and implementation specifics. Developing robust monitoring and evaluation, participation, and finance components seems more difficult. We highlight good practices across all components of the NAP-GP framework, along with actionable, contextual policy recommendations to enhance the quality of NAPs, promote peer-to-peer exchange, and strengthen global adaptation efforts in alignment with the objectives of the Paris Agreement and its Global Goal on Adaptation.

The clean energy transition promises substantial societal benefits but risks reinforcing existing inequalities if its costs and benefits are unevenly distributed. While distributional impacts have gained increasing attention in climate and energy policy analysis, many modelling frameworks remain limited in their ability to represent socioeconomic heterogeneity, bottom-up technology choices, and citizen-centred transition pathways, particularly in electricity systems with high shares of variable renewable energy. As a result, such frameworks may misrepresent electricity affordability, conceal regressive impacts, and support policy recommendations that overlook vulnerable households. This study addresses this gap by integrating bottom-up modelling with distributional impact assessment, using the Greek power sector as a case study. We develop alternative transition scenarios based on storylines informed by the concept of energy citizenship and future-world narratives. These scenarios are embedded within the OSeMOSYS modelling framework to assess alternative system-planning evolutions, costs, and emissions under conditions of heightened uncertainty and external shocks. Model outputs are subsequently combined with household budget survey data to evaluate how costs are allocated across income groups, accounting for heterogeneity in electricity consumption patterns. Our results show that decentralised, solar-oriented transition pathways could significantly improve electricity affordability compared with centralised alternatives by 2050, reducing electricity bills as a share of total income (2.4% versus 4.6%) and substantially narrowing affordability gaps between the lowest and highest income groups (6.3% versus 11%). Overall, our findings demonstrate that least-cost electricity system designs do not necessarily align with socially equitable outcomes and provide insights for designing just and inclusive energy transitions.

Energy models have been a valuable tool in support of well-informed decision-making towards the transition to climate neutrality in the European Union. However, considering the extra levels of detail required when designing a system based on intermittent renewables, modelling approaches in the field often lack the necessary time resolution, or are not open source, raising concerns of transparency and scientific reproducibility. This article addresses this gap by introducing a novel bidirectional soft-linking approach between two open-source energy models to generate long-term scenarios in the power sector and evaluate their feasibility, allowing for the optimisation of investments over a 30-year period and the sector's hourly operation at different snapshots. To demonstrate the applicability of this modelling approach, the Greek power sector is used as a testing ground in order to study the capacity and flexibility requirements of different transition pathways by 2050. Simulation outcomes show that a more ambitious variable renewable energy and storage capacity expansion than the one projected by the National Energy and Climate Plan is required to achieve the targets of 2050, while also highlighting a path dependency on gas at least until 2033. The latter could either result in a lock-in effect or to stranded assets if the decision to phase out gas is not taken rapidly. On the other hand, there is the potential to achieve carbon neutrality by 2035, if significant investments take place in time. Finally, switching from natural gas to hydrogen could be an effective solution for new gas power plants to avoid becoming stranded assets.

This policy brief is part of the theme Optimal Transition, which investigates how to best manage the energy transition in Europe, through national and European climate and energy targets, decarbonisation of electricity generation, and electrification of energy services, guided by the following research question: What are the different cost, energy security, and resilience metrics and how do they compare for different scenarios? The consultative process helped us evaluate the relevance of policy issues, refine the scope of research questions, and establish a balanced group of stakeholders to participate. We conducted one workshop under each theme alongside the corresponding core working group to consult stakeholders on our scenario design and co-define desired outputs as well as a key set of joint input assumptions. During the workshop conducted under this theme, we sought feedback on the scenario design, inputs, and projections of two proposed modelling studies. The participating stakeholders, including representatives from the DG ENER, the Agency for the Cooperation of Energy Regulators (ACER), and the renewable energy industry, provided insights on the most policy relevant aspects of energy system security, resilience and flexibility. Suggestions were also offered to IAM COMPACT partners on specific metrics that could be used to assess model results along these criteria.

AbstractIntroducing carbon taxation could accelerate systemic change towards a decarbonised future. In this book chapter, we aim to test to which extent this policy can be considered a tipping intervention that can encourage fast green technological innovation and infrastructure development in coal and carbon-intensive regions (CCIRs) and how this policy affects the sectoral structure of the economy. We use a dynamic stochastic general equilibrium model (ΜΕΜΟ) to assess the impacts of implementing a carbon tax on GDP and unemployment in Poland and Greece. These two countries are currently phasing out coal. Our results show that carbon tax implementation significantly affects the macroeconomic indicators and may also lead to considerable labour market effects on sectors other than mining, such as the light industry and construction in Greece and energy-intensive and advanced manufacturing industries in Poland. We also discuss funding and recycling revenue mechanisms that could enable the successful implementation of a carbon tax. We conclude that it would be more reasonable to treat carbon tax as an additional political tool that must be combined with other interventions coordinated with an overall broader full-system transformation narrative rather than a single tool that can determine or ex-ante detect any future tipping point.

The ever-growing need for boosting energy efficiency implementation towards achieving the targets set at a European level till 2050, has made the upscaling of energy efficiency investments an imperative. This endeavor requires the analysis and evaluation of energy efficiency investments with respect to all the related technical aspects and uncertainty factors. Nonetheless, up to date, despite the existence of a critical body of literature that delves into this field, a significant gap exists as regards the transparent and rigorous study of energy efficiency investment risks from a holistic point of view and the time that are triggered during energy efficiency projects’ life cycle, while stakeholders’ perspective is usually not taken into consideration. In this context, this paper tries to identify the whole spectrum of risks and uncertainties that can arise in energy efficiency financing and to classify them with respect to the project phase that are probably to be triggered. Moreover, it aims to identify the proposed risk mitigation strategies to deal with the risks arisen and reduce their impact. In this effort, the study follows a systematic literature review to synthetize the respective literature, while the view of key players in energy efficiency financing is incorporated into the analysis through relevant projects’ outcomes. Our results indicate that the risks in energy efficiency financing can be classified over eight general categories, with the ones referring to the regulatory framework of the country of implementation and the technical aspects of energy efficiency projects being the most referenced ones.

Energy efficiency investments are subject to various risks and uncertainties, which may affect involved actors’ profitability, and as such, there is a need for developing tools to support their decisions. So far, the developed methodological frameworks that aim at projecting the profitability and risk of such investments present a high technical complexity, and involved actors have difficulties in digesting their results. Consequently, despite their technical and academic value, the existing frameworks cannot achieve the essence of their scope, i.e., to provide concrete implications to capital providers. This article introduces the concept of IRR curve, as an appropriate tool for assessing the economic performance of energy efficiency investments from investors’ point of view. Based on this tool, an integrated framework for profitability assessment of energy efficiency investments is developed, by linking their economic performance and riskiness to investor preferences. The added value of this methodological framework lies in the comparability that it provides between different energy efficiency investments, thereby facilitating investment selection. Utilising this framework, capital providers can be supported in the selection of the country, sector, and project type to invest, while on the other hand, they can better comprehend the risk nature of energy efficiency investments as well as project their profitability and optimal investment holding period. To demonstrate the functionality of the proposed framework, we applied it to the German energy efficiency sector. Our findings provide evidence for the profitability potential of energy efficiency investments and implications about investment holding period.

There are considerable differences in the pace and underlying motivations of the energy transition in the different geographical contexts across Europe. The European Union's commitment to climate neutrality by 2050 requires a better understanding of the energy transition in different contexts and scales to improve cooperation of involved actors. In this article, we identify critical issues and challenges of the European energy transition as perceived by stakeholders and investigate how these perceptions vary across geographical contexts. To do so, we couple a policy document analysis with research based on stakeholder engagement activities in three different scales, national (Greece), regional (Nordic Region) and continental scale (European Union). Our findings show that stakeholder perspectives on the energy transition depend on contextual factors underlying the need for policies sensitive to the different transition issues and challenges in European regions. They also reveal cross-cutting issues and challenges among the three case studies, which could lead to further improvement of the cross-country collaboration to foster the European energy transition.

Currently electricity markets worldwide encounter a transition phase into cleaner energy. This is specially the case in Greece, where not only the market structure changes to a harmonized EU target model, but also 'green electricity' is projected to reach 50% share by 2030 according to the National Energy and Climate Plan of Greece. This paper presents the extension of the Business Strategy Assessment Model (BSAM) into a computationally efficient central-dispatch wholesale market model. BSAM integrates agent-based profit-maximizing policy making with unit commitment scheduling, into one novel tool that can be used to explore the effects of mid-term market design policies in wholesale electricity markets. BSAM is subsequently utilized to model the Greek market's transitional phase and explore the effects of even higher RES penetration scenarios. Results indicate that the planned short-to-mid-term "de-lignification" and transition of the Greek power system is feasible and will not lead to an excessive RES curtailment situation, but would yield significant CO2 emissions' reductions and small reductions in the system marginal price, with even more ambitious RES shares also being possible.