To ensure broad application of renewable and energy-efficient energy systems in buildings and neighborhoods, profitable business models are vital. Energy supply contracting helps building residents to overcome the barrier of high upfront investment costs while additionally reducing risks related to energy-saving mechanisms. This study examines profitability for energy contractors in a variety of business cases that simultaneously ensure energy cost savings for the residents. A mixed-integer linear optimization model is developed for a neighborhood energy community, consisting of three buildings with diverse usages. In the process, the optimum capacities of building-attached and building-integrated photovoltaics, a heat pump and a gas-fired mini combined heat and power unit are determined to cover the energy community’s electricity and heat load. Results show that cross-domain contracting within energy communities is highly profitable for both, the contractor and the residents, while the extent depends on the accounting method, assumed interest rate and depreciation time. The additional application of energy-efficiency measures in/on the buildings, constituting a combination of energy supply and energy performance contracting, further increases profitability. The investigation of several sensitivities shows that high grid energy costs for electricity and gas enhance profitability of local energy technologies, leading to an increase in optimal technology capacities.

The gradual enactment of legislation for energy communities in individual European countries has increased the public awareness of these novel concepts. While the establishment of individual, isolated energy communities is unlikely to have any far-reaching effects, it is presumed that the large-scale roll-out will indeed significantly impact different stakeholders. Since the diffusion of energy communities is expected to gain momentum within the next years, this study aims to provide a framework to assess the impact of a large-scale roll-out of solar-PV based energy communities. This nine-step framework provides guidance for determining the number of buildings per type and roof tilt, assessing the usable rooftop area for PV installation and realistically installed PV capacities, estimating the number of future residential PV systems based on renewable expansion plans, determining the shares of buildings to be equipped with PV systems, setting up model energy communities, and upscaling. The nine-step framework is not only described theoretically but also applied to Austria as a case study. Thereby, specific focus is put on Austria's rural areas and thus the single-family building stock. Results indicate the impact of a large-scale roll-out of renewable energy communities on participants' electricity bills, electricity suppliers' sales, and grid operators revenues due to reduced grid tariffs for inner-community electricity transfer. The ability to determine the future impacts of energy community roll-out supports stakeholders in their proper planning towards an energy landscape that includes energy communities.

The aim of this study is to provide insights regarding the economic viability of and energy flows within a renewable energy community based on a linear optimisation model with peer-to-peer electricity trading. Different technologies, such as PV, heat pumps, electric vehicles, and a community battery storage, are modelled. With the objective of achieving a cost-optimal solution for the whole community, the individual impacts of different technologies, as well as their permutations, are investigated. Therefrom, financial and environmental advantages and disadvantages for individual participants and the whole community can be derived. The results indicate that customers who are equipped with a combination of PV systems, heat pumps, and EVs achieve better individual results compared to those with lower levels of technology. Especially when heat pumps are involved, the amounts of PV electricity generated can be used with high efficiency, increasing the benefits of energy community participation. Moreover, the higher the level of electricity-based technologies within the community is, the lower the conventional grid feed-in becomes. An additional implementation of a community battery storage can further reduce these amounts and, thus, the grid burden. Apart from the financial benefits, the installation of additional assets and, thus, reduced grid feed-in contribute to the reduction of CO₂-emissions. This study’s results can aid in making decisions regarding investments and energy community composition, as well as in the funding decisions of policymakers.

Based on the European guidelines—the Renewable Energy Directive (RED) and the Electricity Market Directive (EMD)—legislation to enable Renewable Energy Communities (RECs) and Citizen Energy Communities (CECs) is currently being developed in individual European countries. In July 2021, Austria, as one of the first countries in Europe, enacted legislation on both, RECs and CECs. A previous study of Fina and Fechner provided a detailed comparison of the legislative draft for energy communities in Austria, published in March 2021, to the European guidelines. Strengths and weaknesses of the Austrian transposition were highlighted and discussed. Now that the enacted version of the Austrian legislation has been published, important changes from the legislative draft to the final legislation have been identified. Building upon Fina and Fechner, this work aims at supplementing the previous study by examining and critically discussing these changes in order to present the Austrian legislation on energy communities as enacted to an international readership.

This article examines the legal framework for hydrogen production in Austria within the broader context of European Union (EU) regulations, focusing on a company site in Tyrol. At the EU level, the Industrial Emissions Directive, the EU Hydrogen Strategy, the REPower EU Plan, and the Delegated Acts to the Renewable Directive are addressed. For the national regulation in Austria, regulations for electrolyzers (e.g. licensing and safety regulations) as well as the regulation of hydrogen networks—or the absence thereof—are examined. The study assesses the impact of these regulations on an operating location in Tyrol. This analysis reveals the intricate legal landscape shaping hydrogen production in the EU and, specifically, in Austria, highlighting challenges for project development and compliance. The study underscores the need for clarity and harmonization in regulations to support the growth of a sustainable hydrogen economy.