• Energy Research

Abstract A recent article in this journal claimed to assess the socio-technical potential for onshore wind energy in Europe. We find the article to be severely flawed and raise concerns in five general areas. Firstly, the term socio-technical is not precisely defined, and is used by the authors to refer to a potential that others term as merely technical. Secondly, the study fails to account for over a decade of research in wind energy resource assessments. Thirdly, there are multiple issues with the use of input data and, because the study is opaque about many details, the effect of these errors cannot be reproduced. Fourthly, the method assumes a very high wind turbine capacity density of 10.73 MW/km2 across 40% of the land area in Europe with a generic 30% capacity factor. Fifthly, the authors find an implausibly high onshore wind potential, with 120% more capacity and 70% more generation than the highest results given elsewhere in the literature. Overall, we conclude that new research at higher spatial resolutions can make a valuable contribution to wind resource potential assessments. However, due to the missing literature review, the lack of transparency and the overly simplistic methodology, Enevoldsen et al. (2019) potentially mislead fellow scientists, policy makers and the general public.

AbstractThe sheer number of alternative technologies and measures make the optimal planning of energy system transformations highly complex, requiring decision support from mathematical optimisation models. Due to the high computational expenses of these models, only individual case studies are usually examined. In this article, the approach from the author’s PhD thesis to transfer the optimisation results from individual case studies to many other energy systems is summarised. In the first step, a typology of the energy systems to be investigated was created. Based on this typology, representative energy systems were selected and analysed in an energy system optimisation model. In the third step, the results of the representative case studies were transferred to all other energy systems. This approach was applied to a case study for determining the minimum costs of energy system transformation for all 11,131 German municipalities from 2015 to 2035 in the completely energy autonomous case. While a technical potential to achieve energy autonomy is present in 56% of the German municipalities, energy autonomy shows only low economic potential under current energy-political conditions. However, energy system costs in the autonomous case can be greatly reduced by the installation and operation of base-load technologies like deep-geothermal plants combined with district heating networks. The developed approach can be applied to any type of energy system and should help decision makers, policy makers and researchers to estimate optimal results for a variety of energy systems using practical computational expenses.

Renewable & sustainable energy reviews 200, 114500 - (2024). doi:10.1016/j.rser.2024.114500 Published by Elsevier Science, Amsterdam [u.a.]

Increasing energy autonomy is one of the main reasons for municipalities to invest in renewable energy technologies. In this study, the potential of weather-robust autonomous energy systems is evaluated for 11 003 German municipalities in over one million parallelized techno-economic optimizations utilizing high-performance computing clusters. For this purpose, a holistic municipal-level energy system model (ETHOS.FineRegions) was developed that minimizes annualized system costs in 2045. The completely energy autonomous supply can be established in around 90% of German municipalities corresponding to 50% of the country‘s population. Especially highly populated municipalities often do not have the capacity to meet their own energy demands due to low wind and open-field PV potentials. Large rooftop PV capacities account for 40% of installed capacity in the autonomous municipalities. Seasonal storage needs are met by large underground thermal storage tanks and batteries provide intraday storage. Furthermore, huge capacity increases are often required for the final 20% of energy demand to be met in order to achieve a degree of autonomy of 100%. The large storage and rooftop PV capacities lead to high specific system costs in the autonomous municipalities with between 144 €/MWh and 174 €/MWh on average, depending on legislation and opposition towards onshore wind installations. By paying a premium of up to 50% compared to the grid-dependent system, 3945 municipalities with 17.2 million inhabitants could become completely autonomous by 2045. For regions that could achieve an autonomous energy supply at moderate costs, however, lost revenues through energy exports could be a decisive argument against autonomy efforts.

Abstract This paper analyses the potential of the Power-to-Gas (PtG) concept in Baden-Wurttemberg (BW), south west Germany. A macroeconomic analysis shows that a cost-covering operation of PtG for hydrogen production is first possible under our assumptions in 2030. Previous model-based analyses for Germany identified locations, mainly in north-west Germany, where these plants could achieve these full load hours and thus be economical in the future energy system by 2040. Importantly, although some short-term storage devices (batteries) are installed in BW in this scenario, no PtG plants are seen at the level of the transport network. A more detailed analysis for BW at the municipality level develops residual load profiles for individual 110 kV transformers and municipalities. A very large increase in the residual load profiles in the north-east of Baden-Wurttemberg by 2040 is encountered, suggesting a requirement for network strengthening and local storage, including PtG, in this area. Four very different and representative model regions are further analysed, whereby only Aalen, a region with large wind potentials in the north east of BW, is identified as having significant potentials for PtG by 2040 (between 69 and 155 MWel). The current restrictions for injecting hydrogen into the gas network (2–10% by volume) mean that these PtG plants would have to incorporate a methanation step in order to upgrade and feed in SNG. The generation of SNG on a local level is therefore expected to be an option by about 2040, if the development of renewable energy generation proceeds as quickly as expected in the current energy-political scenario explored here. The existing CO2 sources for methanation are not located in the vicinity of the expected PtG plants, so that a CO2 separation from the air and/or a liquefied transport could be most economical. Further work is required to consider the local energy infrastructure, especially electrical and gas distribution networks.

Solar energy 265, 112094 (2023). doi:10.1016/j.solener.2023.112094 Published by Elsevier Science, Amsterdam [u.a.]

Energy and buildings 319, 114411 - (2024). doi:10.1016/j.enbuild.2024.114411 Published by Elsevier Science, Amsterdam [u.a.]

Little is known about the role of active peer effects (interpersonal contact) compared to passive peer effects (noticing or seeing) regarding residential photovoltaic (PV) diffusion. Recent literature suggests that peer effects are determined by the perceived credibility of one’s active peer connections regarding PV and passive peer effects. Utilising data from a survey of German house owners who either own a PV or indicate purchase intention (N = 1,165), this paper explores the underlying mechanisms of active peer effects during different stages of PV adoption decision-making. Our findings suggest that the perceived credibility of peers on PV related issues is positively associated with the reported number of adopters in the decision-maker’s peer group (passive peer effect) and also with the progress in the PV adoption decision process. Furthermore, we find a relationship between the perceived credibility of peers regarding PV and the reported influence strength of peer interactions throughout the decision-making processes of German householders, suggesting that subjective evaluations of peers play a role in active peer effects. Finally, we observe an association between the rate of self-initiated peer interactions about PV for respondents with a higher reported number of peers that have adopted PV, suggesting that passive effects (knowing peer PV adopters) play a role in initiating active peer interactions. These results are significant for all sub-groups, regardless of the decision progress. From a policy-making perspective, “bottom-up” efforts such as peer consultation and community-led outreach should be promoted in Germany to empower potential adopters.