This paper focuses on the battle for a dominant design for renewable hydrogen electrolysis in which the designs, alkaline and proton exchange membrane, compete for dominance. First, a literature review is performed to determine the most relevant factors that influence technology dominance. Following that, a Best Worst Method analysis is conducted by interviewing multiple industry experts. The most important factors appear to be: Price, Safety, Energy consumption, Flexibility, Lifetime, Stack size and Materials used. The opinion of experts on Proton Exchange Membrane and alkaline electrolyser technologies is slightly skewed in favour of alkaline technologies. However, the margin is too small to identify a winner in this technology battle. The following paper contributes to the ongoing research on modelling the process of technology selection in the energy sector.

The decarbonisation policies for the EU building stock can improve living conditions, including thermal comfort and lower energy bills. However, these measures may impose financial burdens on low-income households, reducing their disposable income and exacerbating their vulnerability. The current study investigates the impact of decarbonisation policies on the EU’s building stock, with a specific focus on Minimum Energy Performance Standards (MEPS), the new Emissions Trading System (ETS2) for buildings, and the phase-out of fossil heating systems. By employing a linear, static latest version of Microsoft Excel (Microsoft 365)-based model and analyzing Eurostat data, this study quantifies the effects of these policies on energy consumption, costs, and necessary investments. Moreover, the study emphasizes their implications for low-income groups using vulnerability indicators. The findings demonstrate that a combination of MEPs, ETS2, and phasing out fossil heating systems effectively reduces energy consumption and costs across most countries. However, implementing ETS2 alone may lead to energy reduction and discomfort for low-income groups without addressing underlying demand-side issues. To address this, this study recommends the implementation of more ambitious MEPs or the provision of additional funding alongside ETS2. The phase-out of fossil fuel boilers emerges as the most cost-effective measure in the medium to long term. While MEPS and the phase-out of fossil fuel boilers improve living conditions, they also impose upfront cost burdens and reduce disposable income for low-income households. Therefore, high subsidy rates and supportive policies are necessary to ensure equitable access to investments. The main recommendations include (a) shifting financing to renewable heating systems for low-income households by 2025, addressing cost issues and policies favouring gas boilers; (b) implementing high-funding rate subsidies for energy efficiency in low-income households before 2025, with technical guidance; (c) prioritising the Energy Efficiency First principle in planning to avoid additional emissions or higher costs for low-income households; and (d) considering the energy behaviour of low-income groups in regulations, employing a combination of policies to achieve desired outcomes and ensure thermal comfort.

This paper introduces the Composite Energy and Transport Poverty Indicator (CETPI), a tool designed to address rural vulnerabilities in the EU, with a focus on Croatia, Italy, and the Netherlands. By assuming a social practice theory perspective, this article explores the intersection of energy and transport poverty, emphasizing the need for a far more holistic approach to capture the complexity of these phenomena. Using data on household energy consumption, transport expenditure, and socioeconomic variables, the study developed a replicable indicator, pointing at areas where disparities in energy and transport access might be elusive and therefore unaddressed. As such, the findings reveal that rural areas experience unique challenges, including generally higher costs and limited access to affordable services, contributing to deeper levels of social exclusion. The CETPI provides policymakers with a framework to better understand these intertwined issues to inform targeted interventions that can alleviate both energy and transport poverty. The paper concludes by advocating for policy solutions that can improve equitable access to essential services for vulnerable rural populations.

Peer-reviewed paper 4-078-26 With the transposition of the Energy Efficiency Directive (EED) still lacking uniformity across the European Union (EU), the European Commission urges prompt implementation of decarbonisation actions. The design and implementation of energy efficiency-oriented measures are reportedly lagging, as energy planning requires expert knowledge and resources to capture, assess, and monitor the multiple impacts (MI) of energy efficiency (EE). At the same time, Article 3 of the EED recast explicitly promotes the integration of cost-benefit analysis to enhance transparency and evidence-based justification through appropriate context-sensitive tools. This paper discusses how capacity-building activities support EU planners in capturing and integrating EE and MI into planning processes, enabling them to overcome persistent planning barriers and to achieve set objectives. For this reason, a contextual analysis of empirical evidence was conducted, based on qualitative data collected during trainings on the use of the Multiple Impacts Calculation Tool (MICATool), involving representatives from ministries, research institutes, and energy agencies from 7 EU countries. By confronting current practices, insights were derived regarding planning goals and barriers, as well as the added value of capacity-building for capturing MI and for the successful implementation of EE measures. The results reveal that planners need to address complexity and data gaps, while facing cross-sectoral communication challenges that hinder planning processes. The study further discusses the incremental role of capacity-building within planning systems, portraying it not only as a means for knowledge distribution but also as a vehicle for situational analysis and awareness across planning contexts. Finally, the paper argues that despite the numerous available EU capacity-building activities, common planning barriers across countries demand structural changes in planners’ training, based on greater institutionalisation, continuity, contextualisation, and silo-breaking across disciplines, sectors, actors, and borders. Ultimately, only through such systemic reforms can EU energy planners be adequately equipped to bridge the gap between policy ambition and on-the-ground implementation, accelerating the transition toward a decarbonised EU.