• Energy Research

Three load matching indicators (self-consumption rate, self-sufficiency rate, loss of load probability) and the CO2 emissions were evaluated for 55 Cypriot households with 3 kWp rooftop photovoltaic (PV) generators. The calculations were performed using 30-minute generation and consumption data from a large scale smart meter project in Cyprus. To investigate the effects of recent advances in local legislation, an analysis for higher PV capacities (5 kWp and 10 kWp) was also performed. The PV generation profiles for 5 kWp and 10 kWp PVs were obtained by scaling the 3 kWp PV generation profiles. The results showed that the self-consumption of the analyzed households varied seasonally, as it was related to their heating and cooling demand. More interestingly, the ratio between the households’ annual electricity generation and demand, formally defined here as generation-to-demand ratio (GTDR), was found to be related to the value ranges of the studied load matching indicators. Hence, on average, households with 3 kWp PV generators annually self-consumed 48.17% and exported 2,415.10 kWh of their PV generation. On the other hand, households with larger PV generators were characterized by a higher GTDR, but lower load matching capabilities. For the cases of 5 kWp and 10 kWp PV generators, the average self-consumption fell to 34.05% and 19.31%, while the exported PV generation was equal to 5,122.47 kWh, and 12,534.90 kWh, respectively. Along with lower load matching capabilities, households that generated more than they consumed were also found to have a lower potential for CO2 emissions reduction per installed kWp within the boundaries of the building. In this context, the GTDR could be used by stakeholders to characterize buildings, infer possible value ranges of more complex indicators and make evidence based decisions on policy and legislation.

Abstract This paper is an editorial for the virtual special issue (VSI) of Renewable and Sustainable Energy Reviews (RSER) dedicated to the 14th Conference on Sustainable Development of Energy, Water and Environment Systems (SDEWES 2019) held from October 1, 2019 to October 6, 2019 in Dubrovnik. The VSI published both high quality review papers and original research articles presented at SDEWES 2019 that were of relevance to RSER. A total of 38 articles from the SDEWES 2019 were invited by the guest editors for this VSI. After a scrutinizing peer review process, 28 articles were accepted and published. These articles fall into three broad categories, dealing with smart energy communities, bioenergy and solutions for sectors that are difficult to decarbonize, and produce knowledge relevant to a number of Sustainable Development Goals (SDGs). This editorial discusses the contributions of the articles relevant for expanding the knowledge on the use of demand side flexibility, advancing the three visions of the bioeconomy, moving forward on the difficult challenges for a sustainable energy system and developing effective tools and guidelines for policy makers. Also, the editorial identifies synergies and trade-offs with a number of SDGs, confirming that the generated knowledge is a valuable support to the 2030 Agenda for Sustainable Development.

Since 2015, the intended climate actions of the Paris Agreement signatories have been reported as nationally determined contributions (NDC). These climate actions are fully aligned with the 13th Sustainable Development Goal (SDG) which calls for urgent action to combat climate change. The same, however, cannot be said for their relation to the other 16 SDGs of the 2030 Agenda for Sustainable Development, since climate action can either enhance or compromise the prospects for SDG implementation. In light of this challenge, this paper proposes a simple method for quantifying the synergies and trade-offs between national climate actions and the SDGs. The method, referred to as Q-SCAN, makes use of a seven-step scale and the SDG Climate Action Nexus tool. The effectiveness of the method has been demonstrated on a case study of North Macedonia, a non-Annex I, Western Balkan country with a coal-intensive energy system. Based on the experience in the preparation of the country’s enhanced NDC, the paper elaborates how the method can be used to contribute to the alignment of the national climate actions with the SDGs and how it can be used to improve stakeholder engagement.

Abstract This paper provides a systematic review of 34 large-scale projects of power-to-heat demand response. The projects have been classified in terms of location, size, technical implementation and objective. The chronological ordering of the reviewed projects enables key takeaways to be drawn considering other developments in the energy sector, such as its restructuring and the emergence of competing flexibility options. The presented approach provides renewed insight to the debate on power-to-heat demand response diffusion. Historically, power-to-heat demand response has been used because of its wide availability on the demand side. Within utility programs, it has mostly been used to deal with infrastructure capacity limitations. This is still a major driver for power-to-heat demand response today. To address the challenges that come with the integration of renewable energy sources, more recent research projects have focused on exploring its capability to provide real-time balancing and frequency response at a smaller scale. The literature review suggests that the period of energy sector restructuring introduced uncertainty to energy companies regarding power-to-heat demand response and thus influenced its use. This period is now superseded by developments focused on electricity markets that are open to the demand side. Considering the flexibility requirement of the future energy system, new opportunities arise for power-to-heat demand response. Based on a critical analysis of the technical and regulatory changes, this paper makes the claim that the economic and policy frameworks have had a much more significant effect on the varying diffusion of power-to-heat demand response than the effect of the control and information technologies. In that sense, market rules should be carefully tailored so as to unlock the flexibility not only of power-to-heat demand response, but also of other flexibility resources.

Implementing sophisticated battery control algorithms by overriding the inverter’s built-in battery controls may introduce technical bottlenecks and additional costs. Such an approach is therefore rarely justified for small scale, behind-the-meter storage. This paper focuses on determining the parameters of an inverter-enabled, rule-based control strategy so that the battery is governed similarly to when an optimization-based strategy is used. A five-step procedure has been proposed for the determination of the operational parameters. High resolution measurements of the electricity consumption and PV generation of a pilot case are used to simulate system’s operation. Results of the simulations for days with high and low solar insolation are presented.

Abstract Due to the potential for deploying distributed generation, improving energy efficiency and adopting sustainable energy-related practices, consumers provide significant value in the energy sector transformation. If their interests and goals are similar, they can group together and form energy communities. Energy communities enable consumers to jointly pursue their individual and collective economic, environmental and social goals, while simultaneously contributing to the decarbonisation of the energy system. Considering the growing interest in this field, this paper aims to enhance the understanding of the social arrangements, the technical designs and the impacts of energy communities. The social arrangements of energy communities are discussed in relation to the different actors, their roles and interactions. Then, the paper reviews the technical aspects of designing various local energy systems, while taking into account the goals of energy community members and outside actors. The reviewed literature is benchmarked with respect to the methods, modelling objectives and the constraints used in the design process. Finally, the paper quantifies the economic, environmental, technical and social impacts of energy communities, reviews the numerical indicators used to quantify these impacts and provides a critical discussion of the findings. Based on the findings, future research directions are highlighted.