Renewable Potential Research Articles

Dynamic Maceration of Acerola (Malpighia emarginata DC.) Fruit Waste: An Optimization Study to Recover Anthocyanins

Acerola (Malpighia emarginata DC.) is a tropical fruit with a vibrant red color attributed to anthocyanins, natural pigments, with several applications in the food, nutraceutical, and cosmetic industries. Therefore, the suitability of acerola fruit waste for producing anthocyanin colorants by dynamic maceration was investigated. The extraction process was optimized by combining the factors time (2–90 min), temperature (20–90 °C), and ethanol percentage (0–100%) in a central composite rotatable design (CCRD) coupled with response surface methodology (RSM). The extraction yield determined by a gravimetric method and the levels of cyanidin-O-deoxyhexoside and pelargonidin-O-deoxyhexoside anthocyanins quantified in the 20 run extracts by HPLC-DAD were used as dependent variables. After fitting the experimental data to a quadratic equation, the obtained statistically valid predictive models were used to determine optimal macerating conditions. Under global settings (25 min processing at 41 °C with 12% ethanol), the extraction yielded 57.1% (w/w) and each gram of extract contained 2.54 mg of anthocyanins. Overall, this study highlights the renewable potential of acerola fruit waste for obtaining natural anthocyanin extracts that could represent a sustainable alternative to artificial colorants used in food and other products.

A new index to evaluate renewable energy potential: A case study on solar, wind and hybrid generation in Northeast Brazil

Human activities imply a high and increasing consumption of electricity. In this context, renewable sources, such as solar and wind energy, stand out due to the ecological and economic advantages associated with their use, but bring with them the need for monitoring and analyzing climatic variables such as solar irradiation and wind speed, in order to determine the potential of solar, wind or hybrid (solar and wind) generation of a region. The main objective of the present study was to develop a method to rank the top locations or regions for wind, solar and hybrid electricity generation potential. In addition, two databases were created using spatial interpolation techniques to define values related to solar and wind energy sources in a case study for the state of Paraíba, Northeast Brazil. Thus, using public data from ground stations and satellites, two interpolation procedures were evaluated, Inverse Distance Weighted (IDW) and Kriging. Next, the best evaluated method (Kriging) was used to develop a database with exclusive resolution of 0.05° (latitude and longitude) for analysis of the wind, solar and hybrid potential of the Paraíba state, Brazil, used as case study. Finally, an index was created to determine the municipalities in the state that stand out with the best indicators for hybrid generation. From the index created, it was observed that the municipalities belonging to the intermediate geographical regions of Sousa-Cajazeiras and Patos have the best indicators for solar generation, while the regions of Campina Grande and João Pessoa stand out with greatest potential for wind energy production. The region of Campina Grande also had the best results for hybrid generation potential. The IP-PB index was the main contribution of this work, since the method can be applied to different regions of the world for the same purpose and other indexes for estimating renewable production potential were not found in the literature.

Application of the Principle of Prevention to land-based sources of marine pollution: an International Law approach

Despite being a major environmental issue, marine pollution of onshore origin has not been addressed through a clear and coherent international legal framework. The aim of this article is, therefore, to reconduct such fragmented framework to a single international rule, with the potential of effectively facing the issue. This led the investigation to focus on the Principle of Prevention, which, despite being a cornerstone of international environmental law, has remained quite evanescent as to its normative content. With this in mind, the article attempts to reconstruct the actual content of the rule with specific regard to the issue at stake. In order to do so, it has been essential to identify the standard of “diligence” States are held to in such regard and to verify how such “due diligence” interacts with the primary rule and contributes to fill it with normative content. The result is a single legal rule with a renewed potential, especially in terms of enforcement opportunities.

Pyrolysis kinetics, physicochemical characteristics and thermal decomposition behavior of agricultural wastes using thermogravimetric analysis

This study specifically focuses on pyrolysis kinetics and thermochemical decomposition of important nonedible agricultural wastes (orange filter cake, pomegranate filter cake, poplar branch, corn stalk, sugarcane bagasse, olive pomace, hazelnut glume, hazelnut shell, walnut shell and pistachio shell) with high renewable energy generation potentials. The novelty of this study is to analyze utilization of common agricultural wastes in Turkey for energy applications by evaluating their thermal characteristics and kinetics through pyrolysis from a holistic perspective. Pyrolysis experiments were conducted using a thermogravimetric analyzer (TGA) for the estimation of kinetic parameters by Coats–Redfern method. Differential thermogravimetric analysis (DTG) was carried out to study thermal degradation of biomass components. Ultimate analysis showed that poplar branch had the highest hydrogen/carbon atomic ratio (H/C=1.3) while hazelnut shell had the lowest H/C ratio of 0.9. Fixed carbon content was the lowest in pistachio shell (16.1%) and the highest in pomegranate filter cake (26.8%). The lowest ash content (1.4%) was found for sugarcane bagasse while the highest ash content (9%) was determined for corn stalk. Orange filter cake had the lowest activation energy (Ea) value of 17.8 kJ/mol and the lowest lignin content (4.9%). Poplar branch and sugarcane bagasse had less charring tendency in which char yields at 900 °C were 10.8 and 11.5%, respectively, suggesting that in case of fast pyrolysis where low char is favored, poplar branch and sugarcane bagasse would be better options among the other agricultural wastes studied.

Complementary potential of wind-solar-hydro power in Chinese provinces: Based on a high temporal resolution multi-objective optimization model

In the context of carbon neutrality, renewable energy, especially wind power, solar PV and hydropower, will become the most important power sources in the future low-carbon power system. Since wind power and solar PV are specifically intermittent and space-heterogeneity, an assessment of renewable energy potential considering the variability of wind power and solar PV with high temporal resolution in different regions will facilitate more accurate identification of the decarbonization pathway of power system. In this paper, the complementary output potential of wind-solar-hydro power every 15 min in 31 Chinese provinces is evaluated by developing a multi-objective optimization model based on Nondominated Sorting Genetic Algorithm II. The results show that the total annual complementary power generation potential in China is 17.57 PWh, of which the three components account for 47.8%, 25.3% and 26.9%, respectively. Inner Mongolia and Tibet are the major renewable energy source provinces with annual complementary power generation potential of 5330 TWh and 3907 TWh, accounting for 30.3% and 13.7% of the total power generation potential, respectively. The temporal potential of wind-solar-hydro power varies greatly, with daily potential is more volatile than monthly. Seasonal and spatial heterogeneity of the complemental renewable potential makes some provinces suffer power shortage during long-hours period especially in winter. Our findings will encourage a higher penetration of renewable energy, the promotion of multi-energy complementarity, and the development of inter-provincial power transmission and energy storage infrastructure in China's future power sector.

Geospatial analysis of Indonesia's bankable utility-scale solar PV potential using elements of project finance

Geospatial analysis is useful for mapping the potential of renewables like solar PV. However, recent studies do not address PV’s bankable potential for which project financing can be secured. This paper proposes a framework that incorporates project finance into geospatial analyses to obtain the bankable potential of renewables. We demonstrate our framework for Indonesia, and compare the bankable potential with the socio-economic potential mostly used in literature. Using average inputs On average, the technical potential is 12,200 TWh/year and the socio-economic potential is 152.7 TWh/year if capped by 2030 demand (34% coverage). Considering PV’s financing risks, PV’s bankable potential is 16.0 TWh under current conditions if capped by 2030 demand (3.6% coverage). Both economic potentials are mainly in East Indonesia and absent on Java due to tariffs and land availability. For the bankable potential, the risk perception by banks and investors is another key influence. With a feed-in tariff of 11.5 US¢(2021)/kWh and temporary lift of import restrictions, the bankable potential is 23 TWh if capped by 2030 demand (5.2% coverage) and spreads to Java. For more widespread bankability, additional temporary measures are recommended until the PV’s costs have decreased further and trust by financial institutions has increased.

Long-term optimization of the hydrogen-electricity nexus in France: Green, blue, or pink hydrogen?

We model the optimal hydrogen and electricity production and storage mix for France by 2050. Moreover, an iterative calculation method to represent electrolyzer lifetime based on functioning hours in linear programming is developed. We provide a central scenario and study its sensitivity to the cost of electrolyzers, to hydrogen demand and to renewable energy deployment potential. The proportion of electrolysis to methane reforming with CO2 capture and storage in hydrogen production is sensitive to the cost of electrolyzers, with the former providing around 60% in the central scenario. However, the system cost as well as the hydrogen and electricity production costs are much more robust, thanks to the wide feasible near-optimal solutions spectrum.The electricity production mix is almost fully renewable in the central scenario, while nuclear power has a significant role only if the potential of wind & solar limits their deployment, or if CO2 capture and storage is not authorized. Furthermore, exclusion of reformer-based hydrogen from fossil gas with CO2 capture induces negligible additional cost to the hydrogen-electricity coupled system (below 1%). Therefore, in the current European resilience and sovereignty context, a robust low-carbon hydrogen development strategy would be prioritizing green hydrogen to other low-carbon hydrogen supply options.

Brazilian hydrogen economy development

Hydrogen is being seen as an essential factor in the success of the energy transition. This paper aims to evaluate the status of the hydrogen economy in Brazil and provide strategies for promoting its development. An adapted SWOT and GUT analysis of the Brazilian hydrogen economy is performed and used to identify and prioritize strategies to fully utilise the strengths and opportunities, avoiding or mitigating the weaknesses and threats. The main results of the analysis are the strong potential of renewables and its competitiveness in the Brazilian matrix. The main weakness is the costs of the entire green hydrogen production chain to take advantage of this renewable potential. Another issue is that Brazil is not showing signs of implementing a clear hydrogen strategy, losing the world investment time in Latin America. Since countries like Chile and Colombia already have their strategies ready, giving positive signals to investors.

Industrial Park Renovation Strategy in a Poverty-Alleviated County Based on Inefficient Land Evaluation

China has entered a new era of high-quality urban development. As an important stock resource in the city, old industrial parks face new situations of transformation and regeneration due to various problems such as chaotic land layout, low industrial efficiency, and lack of supporting facilities. However, existing research primarily focuses on case studies in large cities and rural areas, lacking fine-tuned adjustment plans for county-level cities in China. Therefore, this article aims to establish a decision-making and evaluation framework applicable to economically underdeveloped areas, providing a reference for the transformation of inefficient industrial land in county-level cities nationwide. Based on expert consultation, case studies, and other methods, a low-efficiency land evaluation model is constructed from three dimensions: spatial efficiency, operational efficiency, and industry screening, to tap the potential value of stock land. The research data are primarily provided by government departments and processed and quantified using GIS software. Based on the quantitative evaluation results of the Shengfang Industrial Park in Lianhua County, Jiangxi Province, three major strategic directions for land parcels with different renewal potentials are proposed: retention and improvement, rectification and renewal, and redevelopment and utilization. Targeted renewal strategies for the case industrial park are proposed from the aspects of spatial renewal and implementation mode guidance. The results of this study could provide suggestions for local government decision-making, which could contribute to the improvement of resource utilization efficiency and economic benefits. The findings could also provide references for the planning and development of industrial parks in other impoverished counties. Future research could focus on long-term monitoring, stakeholder engagement, and the application of evaluation results.

Connected: rooftop solar, prepay and reducing energy insecurity in remote Australia

ABSTRACT ‘It’s a good life, that solar’. Australia is a world leader in per-capita deployment of rooftop solar photovoltaics (PV) with more than three million households realising benefits including reduced energy bills and improved energy security. However, these benefits are unevenly distributed. Research shows First Nations residents of public housing in remote Australia using prepay metering experience frequent ‘self-disconnection’ from energy services, a known indicator of energy insecurity. Upfront capital costs and an absence of local regulations codifying the ability to connect solar PV have long locked out these households from realising benefits of energy transition in regions host to world class renewable energy generation potential. This article describes early experiences of those residents among the first to install and grid-connect rooftop solar to prepay in Australia’s remote Northern Territory. In addition to reduced electricity expenditures, rooftop solar PV mitigates experiences of energy insecurity through reducing the incidence of involuntary ‘self-disconnection’ due to inability to pay. Support for rooftop solar for prepay households can alleviate frequent exposure to disconnection, bringing multiple co-benefits. Policy responses should focus on reducing barriers to realising the benefits of rooftop PV for priority communities, including First Nations families living in public housing using prepay.

A Decision Support GIS Framework for Establishing Zero-Emission Maritime Networks: The Case of the Greek Coastal Shipping Network

Sustainability of maritime operations is a topic widely considered in recent years, as the shipping industry attempts to limit its environmental impact and meet the decarbonization goals set by the International Maritime Organization (IMO). As alternative fuels and newer ship technologies are gaining interest, the shift to more environmentally friendly fleets is quickly becoming a reality. In this context, potential areas for such shifts need to be determined, to expedite decarbonization efforts and provide passengers with a more sustainable way of travel. Greece is an insular country, with a complex coastal shipping network connecting the mainland with the islands and being of paramount importance for their economic growth. Recognizing accessibility and decarbonization needs, this paper examines whether the Greek coastal shipping network (GCSN) can be restructured, by introducing zero-emission sub-networks operated by electric ferries. The aim is to propose a methodological framework for the spatial analysis and evaluation of coastal networks, with the implementation of exploratory spatial data analysis (ESDA) methods and determination of local indicators of spatial association (LISA) with the help of geographic information systems (GIS). The proposed framework provides insight on whether and where such a restructuring is possible, with the introduction of new transshipment port hubs in the islands from which electric ferries could operate, thus determining potential electrification areas with additionally high renewable resource potential. Final conclusions indicate that a potential electrification of certain parts of the GCSN could be possible, while results for GHG emissions reduced by the introduction of electric ferries are calculated.

Typology of terrain vague and emergence mechanisms in post-communist, post-industrial small and medium-sized towns in Slovakia: Case study of Humenné, Strážske and Vranov and Topľou

Abstract There have been many problems associated with underutilized areas in towns, although they also offer significant potential for urban renewal, especially in post-communist, post-socialist countries, where a series of key historical events has caused socio-economic and political changes leading to urban decay. The underlying feature of unused areas is their apparent abandonment, absence of use, lack of identity but high potential. However, not all unused areas should be labelled as brownfields; therefore, we studied the terms commonly used to describe underutilized areas. We chose the term terrain vague to map and describe all apparently empty but still intriguing spaces in our model towns of Humenné, Strážske and Vranov and Topľou, in eastern Slovakia. Our paper aims to create a typology of terrain vague to better understand its manifestation in our conditions. It also aims to determine the causes that led to its emergence or as we call it the emergence mechanisms, in the context of post-industrial small and middle-sized towns in Slovakia. We combined field survey and desktop analysis methods to map terrain vague based on set criteria. We evaluated mapped terrain vague and, using the data, created a typology of terrain vague consisting of nine types and identified three key emergence mechanisms and their subcategories. We based them on commonly used terms that fit within the specific context of our model towns. By using the new typology and emergence mechanism, we can identify patterns running along towns with similar backgrounds that result in similar problems and develop solutions accordingly. Results of our research could be generalized and serve as a basis for future research aimed at finding strategies for revitalizing terrain vague in shrinking post-industrial towns facing different problems than prosperous cities.

Reactive power potential of converter-connected renewables using convex power flow optimization

Converter-connected renewable energy sources (RES) in the distribution network alter the power flow in the network. Often, grid reinforcements and additional local reactive power sources are needed to maintain steady state network operation. Converter-connected RES is an accessible local reactive power source for distribution system operators to optimize network operations. However, the non-linearity and non-convexity in the converter equations make their modelling challenging, which further results in the under-utilization of the reactive power capability from these sources. Oftentimes, the converter-connected generator is partially modelled using only apparent power constraints. This paper presents an approach based on Schur’s complement and piecewise planar approximation to incorporate the converter equations in a convex power flow optimization routine. The advantages of employing complete converter capabilities for optimal operation of the distribution network are studied via simulations on a real distribution network dataset. A comparison between deploying reactive power according to the minimum grid codes requirement, partial modelling of the converter, and complete converter capabilities is correspondingly presented. Active power losses decrease by 4.1% over 10 month period with high penetration of renewable generation. Furthermore, the voltage profile in the distribution network is improved and the reactive power dependency on the transmission network is reduced.

Fatty Acid Composition and Biodiesel Quality of Brassica nigra, Brassica napus and Sinapis arvensis Seeds

The increasing world population and developing industrial areas increase the need for energy. This situation makes alternative and renewable energy sources and the efficient use of these sources more valuable. In this study, the seeds of Sinapis arvensis, Brassica nigra, and Brassica napus from Brassicaceae family grown in ecological conditions of Bayburt province of Turkey, to determine the usability potential of wild species in biodiesel production. Biodiesel quality characteristics and oil yield and fatty acid composition were determined for the first time for the region using GC-MS. The oil yield of the species included in the study from the Brassicaceae family was found to be between 30.29% and 46.02%. In addition, linolenic acid (7.62%-13.70%) values were determined the lowest in Brassica napus and the highest in Brassica nigra. In terms of flash point (194˚C-195˚C), B. napus and S. arvensis were the closest species. Fatty acid composition and biodiesel quality analysis results of S. arvensis and B. nigra were similar to B. napus. It has been observed that the wild species S. arvensis and B. nigra have renewable energy production potential in terms of biodiesel quality characteristics and fatty acid composition.

Opportunities for CO2 utilisation in the Northern Territory

The Northern Territory (NT) aims to grow the gross state product to $40 billion by 2030 and reach net zero emissions by 2050. Alongside other carbon abatement approaches, CO2 utilisation technologies have the potential to enable the development of a low-emission manufacturing industry that can support the NT’s decarbonisation and economic growth targets. CO2 utilisation is the process of using CO2, captured from industrial emissions or directly from the atmosphere, to produce valuable products. The Northern Territory is relatively well positioned to deploy CO2 utilisation technologies due to the local established natural gas industry, export links with the Asia-Pacific region and high renewable electricity potential. This report explores the potential to deploy five CO2 utilisation opportunities in the NT: methanol, jet fuel, urea, methane, and mineral carbonates. Techno-economic analysis of the levelised cost of production for each of these products found that they are not cost competitive with conventional products. However, cost reductions are expected as the relevant technologies mature. The full report discusses potential scale-up pathways for each application. Commercial-scale CO2 utilisation will require orders of magnitude increases in the scale of CO2 sources, renewable hydrogen, and renewable electricity. CSIRO is collaborating with industry and government partners to develop a business case for a Northern Territory Low Emissions Hub with a particular focus on carbon capture, utilisation, and storage. This abstract provides the high-level finding from the full public report, which is one input into the development of this business case.

China’s Potential for Trade in Renewable Energy Products in RCEP Countries: A Gravity Model Analysis

China’s renewable energy products have an important place in international trade, and the conclusion of the RCEP agreement can create favourable external conditions for China’s renewable energy product exports. This paper measures the export potential of China’s renewable energy products to other RCEP countries through a trade gravity model. The results show that (1) the GDP of the importing and exporting countries, the energy consumption of the importing countries, and the particulate emissions damage significantly enhance China’s renewable energy product exports; (2) among the RCEP countries, China has a greater potential to export renewable energy products to five countries in 2020, which are mainly located in East and Southeast Asia; and (3) from a dynamic perspective, China’s renewable energy trade potential is increasing, while in the Oceania region it is weakening, while trade links to Southeast Asian countries are developing in a more mature direction. Based on the above research, this paper puts forward corresponding policy recommendations.

An Evaluation of ASEAN Renewable Energy Path to Carbon Neutrality

Maintaining our standard of living and keeping the economy running smoothly is heavily reliant on a consistent supply of energy. Renewable energy systems create abundant energy by utilizing resources such as the sun, wind, earth, and plants. The demand for renewable energy is increasing, despite power scarcity, pollution, and climate change posing challenges to long-term development in the Association of Southeast Asian Nations (ASEAN), which has seen significant social and economic growth in recent years. To achieve its 23% renewable energy (RE) target, ASEAN can develop solar photovoltaic (PV) electricity. Members of the ASEAN have established regulations and incentives to encourage individuals and businesses to use renewable energy in the future. This paper explores Southeast Asian countries’ comprehensive fossil-free energy options, the region’s renewable energy potential, current capacity, goals, and energy needs. Through the ASEAN Plan of Action for Energy Cooperation (APAEC) 2016–2025 and the ASEAN Declaration on Renewable Energy, ASEAN is committed to reducing its greenhouse gas emissions and promoting sustainable development aligning with the Paris Agreement’s aim to limit global warming to well below 2 degrees Celsius above pre-industrial levels. Results show that decarbonizing the region’s energy system is possible, but current policies and actions must be altered to reach that target level. Further research is necessary to optimize the ASEAN region’s renewable resource technical potential and commercial viability with available technology.

Hybrid Deep Learning-Based Grid-Supportive Renewable Energy Systems for Maximizing Power Generation Using Optimum Sizing

The hybrid electricity production idea is a technology designed to produce and use electrical energy from many sources as part of an integrated setup. The combined size and power maximization technique for grid-connected renewable energy systems is presented in this research. This study optimizes three distinct geographic locations with various wind and sun renewable energy input potentials. Convolutional neural networks with long short-term memory are designed to maximize electricity production while taking consumer load, demand, and weather conditions into account. The established technique emphasizes the significance of taking into account the concurrent optimization of sizing and power management. To find the hybrid power system building option with the optimum cost–benefit ratio, the Shuffled Shepherd Optimization Technique is used. The optimization analysis uses annual demand data, solar irradiation, and wind turbine power output with a 10-min precision. Investigations have been done into how the system’s various parts behave. The amount of PV panels, wind turbines, battery banks, and the capacity of the diesel generator, together with the error rate, are the best choice factors shown by simulation results for sizing and producing the electricity for hybrid energy system. The results support the proposed strategy’s potential for producing hybrid renewable power.

Enhancing resilience and sustainability of distribution networks by emergency operation of a truck-mounted mobile battery energy storage fleet

Distribution networks have always been exposed to outages due to various internal and external causes. During emergencies, the damaged areas are disconnected and as a result, a portion of the connected loads remained unmet until ending required repairs. Accordingly, utilizing the total renewable potential in smaller islands may be unmanageable and result in curtailment. In this paper, a method is proposed to overcome these challenges by utilizing a fleet of mobile battery storage (MBS) systems. The MBSs will overcome renewable curtailment and unmet load simultaneously during emergencies via a shift in the produced energy. The excess energy produced in the islands with extra generation will be stored and then used at another location and time in the islands without production adequacy. To do this, a multi-stage and spatio-temporal operation model for a fleet of truck-mounted MBS systems based on road transport is proposed. Both time and cost of transportation are considered and modeled by linear formula. The battery lifetime and full four-quadrant power factor of the integrated inverter are also considered. The proposed model aids to decrease computational burden by decomposing the transportation model from the distribution network. Besides, it ensures the minimum cost operation while maximizing renewable resources utilization trapped on small islands. The model is linear and capable of handling real-life and large-scale systems when integrated into commercial distribution software. The model is validated by implementation on the 33-bus distribution grid coupled with a 15-node transportation network and results demonstrate increased resilience besides enhanced renewable resources utilization.

Optimal Allocation Scheme of Renewable Energy Consumption Responsibility Weight under Renewable Portfolio Standards: An Integrated Evolutionary Game and Stochastic Optimization Approach

Developing renewable energy has become a major strategy for China to accelerate the energy transition and combat climate change. Accordingly, a guarantee mechanism for renewable energy consumption with renewable portfolio standards (RPS) has been set in China. However, currently, the top-down allocation of regional renewable energy consumption targets often has issues of unfairness and inefficiency. It is necessary to investigate the issue of how to stimulate the renewable energy consumption potential on the demand side and reasonably formulate the consumption responsibility weights of various market entities. This paper aimed to develop a new methodology for the weight allocation of renewable energy consumption responsibilities. In doing so, an integrated model of an evolutionary game and stochastic optimization was constructed between market entities and governments. Then, the equilibrium strategies of market entities and governments were obtained through the evolutionary game. Furthermore, based on the equilibrium strategies, this paper optimized the renewable energy consumption weight of each market entity, which constitutes the optimal allocation scheme of renewable energy consumption responsibility weights. Finally, using the data of 7069 market entities in Hubei Province in 2021, this study simulated the model to verify its effectiveness and practicability. The results indicate that the willingness of market entities to assume more consumption responsibility is positively correlated with the government’s incentives and the maturity of the green electricity trading market. This study provides important implications for optimizing government regulations and promoting renewable energy consumption.