To accelerate the energy transition, the EU “Clean Energy for all Europeans” package aims to strengthen the involvement of end consumers in the energy market. To this end, together with so-called “active consumers” and provisions for individual and collective renewable energy self-consumption, two types of energy communities were introduced. The EU framework, however, leaves many details of the transposition process to the national level. The corresponding directives were supposed to be transposed by the end of December 2020 (recast Electricity Market Directive, defining active consumers and citizen energy communities) and by the end of June 2021 (Renewable Energy Directive, defining renewables self-consumption and renewable energy communities). In this paper, we critically discuss major developments of the transposition, including questions of the general distinction of the different concepts, governance and ownership, physical expansion, administrative barriers and the overall integration of energy communities into the energy system. The analysis builds on country case studies as well as on previous work by the authors on the status of the transposition process throughout the EU. The paper shows that the national approaches differ greatly and are at very different stages. While basic provisions are in place in most Member States to meet the fundamental EU requirements, the overall integration into the energy system and market is only partly addressed. This concerns, for instance, the analysis of system impacts of energy communities and measures that would allow and support energy system-friendly behaviour. In addition, several practical hurdles need to be overcome. These often relate to administrative requirements such as complex registration and licensing procedures, the need for the involvement of several institutions, or difficult procedures for access to relevant data. The paper concludes that discussed barriers will need to be carefully addressed if the high expectations for the role of energy communities are to be met.

The goal to decrease greenhouse gas (GHG) emissions is spurring interest in renewable energy systems from time-varying sources (e.g., photovoltaics, wind) and these can require batteries to help load balancing. However, the batteries themselves add additional GHG emissions to the electricity system in all its life cycle phases. This article begins by investigating the GHG emissions for the manufacturing of two stationary lithium-ion batteries, comparing production in Europe, US and China. Next, we analyze how the installation and operation of these batteries change the GHG emissions of the electricity supply in two pilot sites. Life cycle assessment is used for GHG emissions calculation. The regional comparison on GHG emissions of battery manufacturing shows that primary aluminum, cathode paste and battery cell production are the principal components of the GHG emissions of battery manufacturing. Regional variations are linked mainly to high grid electricity demand and regional changes in the electricity mixes, resulting in base values of 77 kg CO₂-eq/kWh to 153 kg CO₂-eq/kWh battery capacity. The assessment of two pilot sites shows that the implementation of batteries can lead to GHG emission savings of up to 77%, if their operation enables an increase in renewable energy sources in the electricity system.

The paper presents an agent-based approach to model the flexibility of the demand-side. It uses Q-learning algorithm to model a behavior of a demand-side agent, so to investigate the elasticity of the demand to the change in price. Often, market simulation models assume that the demand elasticity is known, however due the lack of data this elasticity is not easy to determine. The objective of this paper is to evaluate the flexibility of the total system demand, and the shift in the consumption with the price, i.e. increase in the demand when the price is low, and a decrease in the demand when the price is high. The here presented model of a demand-side agent is incorporated into the market simulator with double-sided auctions, and is tested on the Slovenian market. However, this approach can be used to estimate flexibility in any system for which the forecasted demand data and generation offers are know.

Hydropower contributes to a higher share of renewables but is also in conflict with environmental legislation aiming to protect natural habitats, wildlife and endangered species. Analysing two neighbouring European countries with similar topographical and hydromporphological characteristics, Austria and Slovenia, allows assessing to what extent a policies’ national context steers possible policy conflicts of EU legislation. The paper shows that hydropower expansion in examined countries is strongly shaped by factors such as financial concerns of investors, diverging opinions of involved stakeholders, available hydro potential and the role of hydropower in national energy strategies. Addressing issues that lead to a lower effectiveness of national policies already at the level of EU policy design or engaging countries to broadening their national energy portfolio by considering emerging technologies such as PV and wind will enable future energy and climate strategies that are more consistent with other environmental goals.