• Energy Research
• 2021-2025close
• Closed Access close
• UNSW Sydney close

Abstract Distributed optimization algorithms contribute to an insight for the optimal coordination of distributed energy resources (DERs). To tackle the DER coordination problem, this paper studies a composite constrained optimization problem over multi-agent networks, where all agents independently maintain convex objective functions while satisfying the local and coupled constraints. Within the Peaceman-Rachford splitting (PRS) framework, a distributed algorithm based on the relaxed ADMM method is proposed for the considered problem, where agents in the network commonly share a fixed step-size instead of the diminishing one. Finally, the simulations on the optimal coordination of DERs including distributed generators (DGs) and energy storages (ESs) are conducted to validate the effectiveness of the proposed algorithm.

AbstractRecently, the globe has been facing several challenges, and environmental deterioration has become more prominent. Therefore, to deal with such environmental issues, the globe has tried to introduce several green initiatives via the Kyoto Protocol, the Paris Agreement, and the Sustainable Development Goals, but the problem remains intact. However, practitioners have no more choice but to exclude emerging economies from this race. For instance, to understand the response of emerging economies toward a sustainable environment, this study considers BRICS (Brazil, Russia, India, China and South Africa) economies. Similarly, the current empirical study utilizes innovative environmental determinants such as real income, urbanization, entrepreneurial activities, per capita renewable energy, financial innovation and environmental policy for selected regions from 2000 to 2021. However, the findings of the advanced estimators' series show the significant contribution of per capita green energy consumption, environmental policy and entrepreneurial activities toward environmental sustainability. In contrast, income, financial inclusion and urbanization contribute to environmental damage. Because of green energy supportive behavior, this study makes an additional step to investigate the mediating effect on financial inclusion, environmental policy and entrepreneurship. However, the mediating effect only supports environmental policy and entrepreneurship activities to reduce environmental pressure. From the policy perspective, the specified economies should allocate their financial resources to clean & green projects to attain the desired level of sustainability.

A nested transactive energy (TE) market methodology is presented in this paper for the effective utilization of demand-side flexibility of small-scale residential consumers. The consumers’ flexibilities are traded in a local flexibility market to prevent transformer overloading, whereas the demand-side flexibilities are traded in an event-triggered central wholesale demand response market after successive aggregation in the intermediate layers. A two-stage optimization-based scheduling model is presented to optimize the transactive bidding of residential consumers with on-site distributed energy resources and controllable loads. The optimal market methodologies are presented for the integrated TE markets to ensure economic trading for all involved stakeholders. The proposed methodology is numerically validated by simulation studies for different consumer participation levels, and the case studies indicate the efficacy of the proposed methodology for economically feasible procurement of consumer flexibility for transformer overloading and wholesale peak-price events. Results also illustrate that the proposed method offers 2.8–14 times more profits to the participating consumers than the energy-supply incentives according to existing retail tariff structures even considering their thermal discomfort and cycle-aging of storage units for the flexibility support.

Abstract Indoor thermal comfort and air quality in school classrooms are of interest worldwide, primarily because of their potential impacts on students’ health, learning performance and productivity. Further, increasing concerns with changing climate and building energy efficiency highlight the importance of ventilation and comfort in educational settings. The existing literature on indoor air quality (IAQ), ventilation, and thermal comfort in classrooms in subtropical regions of Australia is sparse. Here, we present the results of a field study conducted in secondary school classrooms in Sydney during the school year in 2018 and 2019. We collected data with subjective surveys through questionnaires and with field measurements related to IAQ the thermal comfort in two adjacent similar classrooms. The infiltration and ventilation rates were measured during the non-occupied period using the concentration decay method. We analysed the performance of a cloud-connected demand-controlled mechanical extract ventilation system (DCV), which was installed in one of the two surveyed classrooms during mid-season. Before application of the DCV, CO2 levels were similar in both classrooms with a maximum concentration of approximately 2418 ppm during cold season. The DCV reduced the peak CO2 concentration to 1335 ppm, while CO2 raised to 2981 ppm in the classrooms without DCV during mid-season. Further, Volatile Organic Compounds (VOCs) analysed from air samples show improved air quality in the classroom with DCV. Our results highlight the impact of both indoor temperature and CO2 concentration on students’ feeling of fatigue. Students showed adaptability to indoor temperature change. A period of one week is needed for students’ adaptation to a step change in the mean outdoor temperature. Understanding classroom indoor air quality and thermal environment, as well as students’ perceived comfort, is vital to develop child-based design guidelines for schools.

Warming seas, marine heatwaves, and habitat degradation are increasingly widespread phenomena affecting marine biodiversity, yet our understanding of their broader impacts is largely derived from collective insights from independent localized studies. Insufficient systematic broadscale monitoring limits our understanding of the true extent of these impacts and our capacity to track these at scales relevant to national policies and international agreements. Using an extensive time series of co-located reef fish community structure and habitat data spanning 12 years and the entire Australian continent, we found that reef fish community responses to changing temperatures and habitats are dynamic and widespread but regionally patchy. Shifts in composition and abundance of the fish community often occurred within 2 years of environmental or habitat change, although the relative importance of these two mechanisms of climate impact tended to differ between tropical and temperate zones. The clearest of these changes on temperate and subtropical reefs were temperature related, with responses measured by the reef fish thermal index indicating reshuffling according to the thermal affinities of species present. On low latitude coral reefs, the community generalization index indicated shifting dominance of habitat generalist fishes through time, concurrent with changing coral cover. Our results emphasize the importance of maintaining local ecological detail when scaling up datasets to inform national policies and global biodiversity targets. Scaled-up ecological monitoring is needed to discriminate among increasingly diverse drivers of large-scale biodiversity change and better connect presently disjointed systems of biodiversity observation, indicator research, and governance.