Renewable Supply Research Articles

Impact of Rainfall and Soil Infiltration on Groundwater Dynamics of Yerekoppi-1 Micro-watershed, Haveri District, Karnataka, India

The amount of water infiltrating the soil surface directly affects the quantity of surface runoff and erosion, and the recharge of both soil and groundwater. Groundwater recharge is an informative indicator of the water located beneath the ground surface. It has a direct impact on renewable supplies of groundwater. In the present study on Impact of rainfall and soil infiltration rate was used for effect on the groundwater level of the Yerekoppi-1 micro watershed (Manakur sub-watershed) in Haveri district of Karnataka state. Average annual rainfall is 700.7 mm and mean potential evapotranspiration is 1541.8 mm. An area of about 888 ha (94.32 %) has clay texture at the surface and 53 ha (5.68%) area has contributing settlement. In Yerekoppi-1 micro- watershed, 38 borewells are there in the vicinity of major stream of the micro- watershed. The mean depth of groundwater levels in the micro- watershed were monitored at a monthly frequency during January-2023 to March-2024. It was found that the maximum average depth of bore wells are about 17.6 mbgl and lowest average depth of borewell about 8.8 mbgl. Soil infiltration rate was measured at upper, middle and lower reaches of the watershed area in the year 2023 and 2024. The majority of the area contributed clay soil. In all the areas of micro-watershed, infiltration rate for clay soil is less than 5 mm/hr. Infiltration rates for all the areas was 1.72- 4.78 mm/hr. Soil infiltration during a rainstorm is closely related to a number of factors such as the intensity and kinetic energy of the rainfall, soil surface conditions and soil properties such as those related to aggregate stability. The groundwater recharge may be improved by growing plantation crop for increasing infiltration rate, construction of percolation tanks and farm ponds in the lower most of the agricultural land.

Sun-powered solutions: Investigating productivity and economics of small-scale solar desalination system

Freshwater demand is one of the most critical challenges facing many countries in the world. Jordan is a country in the middle east that is considered one of the poorest countries for renewable freshwater supplies in the world. Though desalination may be one of the solutions to the problem, the cost and energy expenses could be an obstruction. However, with an abundance of annual solar irradiance in Jordan, solar desalination systems, particularly small-scale ones, are considered better alternatives. In this study, a residential-scale solar desalination system is investigated. The design includes evacuated-tube solar heaters with a heat pipe, and flashing units comprising three desalination stages. The experiments included single-stage, double-stage, and triple-stage desalination. The results showed that production rates of 2.2 kg/m2 using single-stage, 4.7 kg/m2 using double-stage, and 6.4 kg/m2 using triple-stage desalination were obtained from the system. The solar water heater used in the system exhibited an average thermal efficiency of 73 %. The economic analysis revealed that the payback period for the triple-stage desalination system is 8 years. The annualized rate of return was calculated to be 2.2 %, assuming the system operates for 4 h per day and 300 days per year.

Evaluating the performance of six 1970s off-gas deep retrofit bungalows

This paper presents the energy and environmental performance of whole house energy systems implemented in six 1970s bungalows in South Wales, owned by Swansea Council. The objective was to reduce energy demand and carbon emissions, maximise renewable supply whilst ensuring a comfortable and affordable home for the residents. The whole house energy system for each home involved the installation of a combination of passive and active low carbon solutions. Detailed monitoring was carried out for a year before and for more than 2 years after the work, annual figures have been validated and normalised for weather. Analysis of monitored data confirms that Standard Assessment Performance ratings improved from 12 to 95. The average annual energy consumption across the six bungalows was reduced from 16,117 to 4560 kWh. 2418 kWh was provided by the PV panels and battery, with 1963 kWh of excess electricity that could be sold back to the grid. Real-life average Ground Source Heat Pump CoP was monitored at 3.3. Embodied carbon for retrofitting each house is estimated at 22,980 KgCO2e +/−20%, approximately 5-years carbon payback. Indoor conditions have been improved with internal temperature and relative humidity achieving standards with residents reporting levels of improved comfort satisfaction. Practical Application A whole house energy system demonstrates the benefits of a holistic, fabric and systems retrofit approach. The work informs how gathering data using appropriate methods assists modelling predictions and decisions throughout the retrofit stages. The study demonstrates extensive monitoring as a vital tool to evaluate the performance of the individual components and the whole system within the home, as used by the residents. Performance evaluation is critical in identifying issues, allowing resolutions to be made both immediately on-site as well for longer term, follow on retrofit programmes. Real-life performance evaluation and visualisation methods are transferable across global building industry.

Smart feasibility optimization of hybrid renewable water supply systems by digital twin technologies: A multicriteria approach applied to isolated cities

This research presents a multicriteria approach for the best hybrid water supply solution of a multipurpose Pumped-Storage Hydropower (PSH) system, using the Generalized Reduced Gradient (GRG) method in Solver, with the optimization process considering key factors, such as Net Present Value (NPV), the number of energy conversion devices, renewable energy production, source availability, reservoir capacities, topographic constraints, and energy tariffs. The methodology combines a literature review, methodological development, and machine learning applications for hybrid water-energy systems. Results indicate that solar-only solutions are insufficient in high hydropower potential scenarios while integrating wind turbines significantly enhances energy production and profitability by generating surplus energy for grid sales. The timing of energy sales and the incorporation of battery storage also impact NPV, which can exceed 180 million euros. Wind energy contributes to continuous profitability and optimized system performance, particularly in isolated regions. The PSH system can manage 130,000 cubic meters of water daily, storing 25 MWh of energy, and reducing CO2 emissions by over 18,000 tonnes per year. These findings highlight the importance of renewables, such as wind energy, and effective operational management. It enhances the economic viability and environmental sustainability of hybrid water-energy systems.

Towards a Green and Inclusive Power Sector in the Greater Mekong Subregion

Abstract This paper examines the power sector and electricity market in the Greater Mekong subregion (GMS) and explores potential pathways for low-cost, low-carbon, and low-conflict development of the sector. The results show that implementing a smartly-designed regional power grid, combined with enhanced cross-border trade, can facilitate a transition to a 100 percent renewable electricity supply. It projects a three-fold increase in energy demand by 2050 and highlights the need for a transition to low-impact renewable electricity sources. It utilizes modelling tools to analyze four scenarios and assess their impacts on electricity cost, carbon emissions, and environmental and social aspects. Results indicate that a scenario combining an expanded regional grid and cross-border trade, increased share of non-hydro renewable energy sources and energy efficiency measures yields the best outcomes. This approach reduces sectoral emissions, lowers costs, and minimizes conflicts. The paper recommends establishing coordinated and functional regional institutions, ratifying a regional grid code, and promoting standardized cross-border power trade arrangements. In conclusion, the report highlights the relevance of a well-designed regional power grid and cross-border trade for a successful transition. Implementing the recommended measures can lead to a greener and more inclusive power sector, ensuring the region’s long-term energy security and environmental sustainability.

Transition to a 100 % renewable power supply in galapagos islands: Long-term and short-term analysis for optimal operation and sizing of grid upgrades

Owing to their remarkable biodiversity and endemic ecosystems, the Galapagos Islands are one of the most important World Heritage sites. However, due to their isolation and remote geographical location, around 83.6 % of the energy supply in Galapagos relies on the use of fossil fuels, which are polluting the air, the land and the sea, therefore requiring an adequate energy planning for the efficient transition towards a more sustainable and environmentally friendly energy sources. Although there were several previous studies of the decarbonization of Galapagos’ energy supply, there is a need for a more comprehensive approach that will combine planning (long-term) and operational (short-term) analysis to evaluate both, the future investment plans and performance of evolving energy supply system, as well as to provide an in-depth evaluation of required system upgrades in terms of locally available renewable energy resources. In order to fill this gap, this paper presents results of two different studies for the optimal decarbonization and transition to a 100 % renewable energy supply of the Galapagos Islands, giving details on the development of modelling tools required for the analysis of different scenarios and various techno-economic constraints. The first study is used for a long-term for analysing and strategic planning of the energy matrix until 2050, starting from existing power plants and following projections for the deployment of new renewable-based energy generation and dedicated energy storage sources to determine the optimal sizing and timing of required grid upgrades. The second study is a short-term annual performance analysis, which considers days of minimum, average and maximum available renewable energy resources to optimize system operation with existing and additional renewable energy generation and storage sources that will minimize, or keep at a certain target level, contributions from diesel generation. The two presented studies complement each other, allowing to evaluate transition to a 100 % renewable energy supply in Galapagos from both the investment/planning perspective and from the operational point of view. The results of two studies are very close in terms of the sizes of required new PV generation and associated energy storage in Baltra-Santa Cruz islands by 2050 (around 50 MW of PV and 145 MW of storage), with the short-term study allowing to identify curtailed PV generation (on average around 140 MWh per day) as an opportunity to connect new controllable loads, and with the long-term study allowing to evaluate interim targets for decarbonization pathways to Net Zero by 2050 through the related techno-economic optimization.

100% renewable heat supply in Berlin by 2050 – A model-based approach

The energy crisis posed major challenges, especially for the heating sector. The European gas price increased from 16€/MWh in March 2021 to 227€/MWh in March 2022, which led to a debate in Germany around reshaping the heat supply to decrease energy import dependence. However, many actors on the heating market are reluctant to make the necessary investments to reduce dependence on natural gas. Although, independence of fossil energy imports by 2050 would be possible with a switch to a 100% renewable heat supply for Berlin.Based on the linear open-source energy system model GENeSYS-MOD, a 100% renewable-based energy system is modeled. GENeSYS-MOD is extended to model district heating, which is crucial for Berlin's heat supply. Furthermore, the modeling of heat pumps and a data set for Berlin is revised.The modeling considers the tightened climate protection targets, which means a 95% CO2 reduction by 2045 compared to 1990. By 2050, 100% of the transport, industry, electricity, and building sectors` emissions are mitigated.The results suggest the immediate exploitation of the existing renewable energy potential and seasonal heat storages, as well as a necessity for a major increase in renovation rates. The upcoming coal phase-out in Berlin in 2030 should be met by a mix of heat pumps and biomass. If heat pump resources are exhausted, direct electric heating is deployed as last resort option.

High-Voltage, Long Term-Stable and Wearable Zinc-Ion Hybrid Batteries with Gel Biopolymer Electrolytes

We are on the eve of the energy transition towards the phase-out of coal, electromobility and renewable power supply. Lithium-ion batteries (LIBs) and electric double-layer capacitors (EDLCs) are complementary energy storage devices supporting this technological change. They have dominated the commercial market of power sources, serving as energy supplies for various technologies ranging from daily electronics and gadgets through electric vehicles to management systems of the intermittent electric grid. However, conventional energy storage systems present some challenges regarding operational safety, the expected increase in production costs, the risk of limited availability of raw natural resources, and universal waste disposal.1,2 Zinc-ion rechargeable power sources, including batteries and hybrid supercapacitors, are a promising alternative to commercial LIBs and EDLCs.3,4 This technology integrates attractive features, such as high gravimetric and volumetric theoretical capacity, low cost, high safety, and environmental friendliness. Nevertheless, the widespread adoption of zinc-ion systems for powering commercial devices still faces challenges related to electrode design, the risk of liquid electrolyte leakage, rigid construction, and the presence of synthetic polymer-based components. This research attempts to address the aforementioned shortcomings by exploring the concept of biopolymer-based zinc-ion systems.Herein, we present zinc-ion hybrid batteries employing gel biopolymer electrolytes. Batteries and dual-ion hybrid batteries of aqueous Zn-ion technology operate according to similar mechanisms, differing on the catholyte side. In Zn-ion batteries, zinc ions are involved in the reactions on both electrodes, whereas hybrid systems have cathodes adopted from alkaline metal-ion technologies, operating according to intercalation/deintercalation processes of monovalent cations, e.g., Li-ion, Na-ion, K-ion, etc.5 As observed, hybrid devices are feasible with fast kinetics, good stability, and flat and high discharge voltage plateau. The application of gel electrolytes additionally improves their performance on the anode side, facilitating Zn stripping/plating processes due to homogeneous current distribution and flat Zn deposition. Generally, the presented idea emerges as a promising strategy, offering an efficient, safe, low-cost, non-combustive, flexible and sustainable technology. Particular attention is paid to overcoming LIB performance and environmental limitations whilst developing wearable features through innovative biobased technological improvements.References(1) Mauler, L.; Duffner, F.; Zeier, W. G.; Leker, J. Battery Cost Forecasting: A Review of Methods and Results with an Outlook to 2050. Energy Environ. Sci. 2021, 14 (9), 4712–4739.(2) Simon, P.; Gogotsi, Y.; Dunn, B. Where Do Batteries End and Supercapacitors Begin? Science (80-. ). 2014, 343, 1210–1211.(3) Wang, Y.; Sun, S.; Wu, X.; Liang, H.; Zhang, W. Status and Opportunities of Zinc Ion Hybrid Capacitors: Focus on Carbon Materials, Current Collectors, and Separators. Nano-Micro Lett. 2023, 15 (1), 78.(4) Tang, B.; Shan, L.; Liang, S.; Zhou, J. Issues and Opportunities Facing Aqueous Zinc-Ion Batteries. Energy Environ. Sci. 2019, 12 (11), 3288–3304.(5) Shi, Y.; Chen, Y.; Shi, L.; Wang, K.; Wang, B.; Li, L.; Ma, Y.; Li, Y.; Sun, Z.; Ali, W.; Ding, S. An Overview and Future Perspectives of Rechargeable Zinc Batteries. Small 2020, 16 (23), 2000730. Figure 1. Work concept. Figure 1

(Invited) Looking Beyond the Stack: A Systems Engineering Approach to Optimize Stack and System Design of Electrolysers

In the coming decade green hydrogen production is expected to grow at an unparalleled rate. Much of the international focus is currently on the Gigawatt scale plants, with regular announcement of new projects. From a European perspective, the rapid scale-up is necessary to reduce the reliance on fossil fuels and achieve CO₂ reduction targets. Importing green hydrogen or derivatives such as ammonia from regions where renewable electricity cost are low, is key driver for investments for the energy intensive industry, especially in the North Western part of Europe. This will require hydrogen production on a very large-scale. In contrast to the differentiation on application level, a one-size fits all approach for stack manufacturing appears to be attractive, with a high degree of standardisation and volume of production.However, as the case for the Netherlands illustrates, there are more drivers for green hydrogen production, such as addressing (regional) grid congestion, improving the business case for offshore wind farm developments, and providing green energy to small and medium enterprises. For all these use cases the requirements for the electrolyser system differ. Aspects such as the variability of the energy supply, capacity factors, logistics for operation and maintenance, available footprint, are application specific. Therefore, electrolyser system designs may need to be optimized for different markets and applications.At TNO we focus on the development, integration and validation of novel materials and innovative cell components for the different generations of electrolyser technology, both for low temperature (liquid alkaline, PEM, AEM) and high temperature electrolysers. To understand and assess the requirements for future generations of electrolyser technology, a systems engineering approach is developed together with the industrial partners. This allows to translate the requirements from the application, to the system and stack design, down to the requirements on a cell and component level.Results will be presented from several studies carried out by TNO and industrial partners in the field of low temperature electrolyser systems to understand: How to optimize a stack design for a specific application. Should an electrolyser be designed to maximize flexible operation and achieve a broad operating range? Or will a high efficiency be the most important target? And how application specific is such an optimisation.How to bring down the cost of the total system. What impact do the design choices for the electrolyser stack have on the complexity of the system around the electrolyser, the balance-of-plant? What can we learn from this for the future stack requirements?How different operating strategies impact a certain design. Which stack requirements change in large multi-stack systems powered by renewable electricity supply? Can different strategies improve overall system performance and bring down the overall cost of hydrogen production?How can the desired safety level be achieved against the lowest cost by optimizing component and stack design? As both the electrolyser technology and the value chains become more mature, a systems engineering approach will be indispensable, bringing together the requirements of the different levels: from application, electrolyser system and stack design, down to the performance of individual components.

(Invited) Dynamic Modeling of Liquid Alkaline Water Electrolyzers: From Laboratory Cells to Industrial-Sized Stacks

The transition of the energy system towards renewable energies creates an enormous demand for green hydrogen produced by water electrolysis [1]. Among the available processes, alkaline water electrolysis (AEL) is already well-developed and cost-effective, as it does not require expensive or critical membrane and electrode materials [2]. If the liquid alkaline electrolyte is maintained at sufficient reaction temperature (60-90 °C), efficient operation of AEL systems is possible with rapid response to fluctuating renewable power supply [3]. However, a critical phenomenon for all low-temperature water electrolysis technologies is the increased gas impurity – especially for hydrogen in oxygen – during part-load operation [4]. This decreases the process efficiency and is safety-relevant as electrolysis systems must shut down when exceeding 50% of the lower explosive limit. These impurities become dominant at low current density since gas production decreases while the contamination mechanisms (diffusion through the separator and convective transport through electrolyte cycles mixing) are almost load-independent. We have developed a comprehensive dynamic model to properly describe the performance of an AEL system, including cell voltage, electrolyte temperature, electrolyte concentration, and gas purity [5]. With this model, it is possible to describe the dynamic operation of a laboratory AEL system with high accuracy. However, if this model is employed for an industry-sized shortstack with more than 1 m2 cell size, predictions and experimental results are in lesser agreement. This is most probably because the present model assumption of perfectly mixed half-cells no longer holds in large cells with a pronounced dependency of the gas fraction over the cell height. Thus, an improved model including this height dependence must be developed.[1] M. Wappler, D. Unguder, X. Lu, H. Ohlmeyer, H. Teschke, W. Lueke, Int. J. Hydrogen Energ. 47 (2022) 33551[2] J. Brauns, T. Turek, Processes 8 (2020) 248[3] J. Brauns, T. Turek, Electrochim. Acta 404 (2022) 139715[4] P. Trinke, P. Haug, J. Brauns, B. Bensmann, R. Hanke-Rauschenbach, T. Turek, J. Electrochem. Soc. 165 (2018) F502[5] J. Brauns, T. Turek, J. Electrochem. Soc. 170 (2023) 064510

A Potential Second Shutoff from AT2018fyk: An Updated Orbital Ephemeris of the Surviving Star under the Repeating Partial Tidal Disruption Event Paradigm

The tidal disruption event (TDE) AT2018fyk showed a rapid dimming event 500 days after discovery, followed by a rebrightening roughly 700 days later. It has been hypothesized that this behavior results from a repeating partial TDE (rpTDE), such that prompt dimmings/shutoffs are coincident with the return of the star to pericenter and rebrightenings generated by the renewed supply of tidally stripped debris. This model predicted that the emission should shut off again around August of 2023. We report AT2018fyk’s continued X-ray and UV monitoring, which shows an X-ray (UV) drop-in flux by a factor of 10 (5) over a span of two months, starting 2023 August 14. This sudden change can be interpreted as the second emission shutoff, which (1) strengthens the rpTDE scenario for AT2018fyk, (2) allows us to constrain the orbital period to a more precise value of 1306 ± 47 days, and (3) establishes that X-ray and UV/optical emission track the fallback rate onto this supermassive black hole—an often-made assumption that otherwise lacks observational verification—and therefore, the UV/optical lightcurve is powered predominantly by processes tied to X-rays. The second cutoff implies that another rebrightening should happen between 2025 May and August, and if the star survived the second encounter, a third shutoff is predicted to occur between 2027 January and July. Finally, low-level accretion from the less-bound debris tail (which is completely unbound/does not contribute to accretion in a nonrepeating TDE) can result in a faint X-ray plateau that could be detectable until the next rebrightening.

Cost-efficient microgeneration renewable energy provision dimensioning for sustainable 5G heterogeneous network

The deployment of mobile networks has imposed an urgent requirement for the pursuit of low-carbon communication infrastructures. The increasing energy consumption of mobile networks has brought about challenges of techno-economic and environmental sustainability. Renewable energy-enabled mobile networks have received a lot of attention due to their capability to evade greenhouse gas emissions and easy availability. Microgeneration-based renewable energy provision is a feasible and effective solution for 5G networks. Dimensioning of microgeneration renewable energy power supply is an essential issue to make the system operate for a long period cost-effectively with a minimum amount of grid energy consumption. For effective deployment of microgeneration renewable energy system, it is essential to provision it with adequate PV panel capacity and storage devices. This work attempts to identify the cost-effective, energy-efficient, and emissions-aware sizing of PV panels and storage for 5G HetNet. An energy-saving strategy based on an optimal policy of advanced sleep modes and traffic-aware load offloading is developed and the interaction of the energy-saving strategy on the system dimensioning is explicitly examined. The proposed solution aims to ensure the communication quality of service whilst keeping the optimal cost-effective deployment and network operation. The system performance in terms of grid energy consumption, empty storage probability, emission performance, and total cost of the system is extensively assessed through experiments for a range of operational scenarios. The numerical results demonstrated that the proposed sustainable energy system dimensioning and operation integrated with an energy-saving strategy is energy-efficient and cost-effective.

An energy system model-based approach to investigate cost-optimal technology mixes for the Cuban power system to meet national targets

Cuba's power supply is characterized by the dependence on imported oil, outdated power plants and frequent power curtailment. Cuba's government aims at changing this situation through the National Economic and Social Development Plan, which targets a renewable share of 37 % in 2030. In the longer term, the Cuban government has already acknowledged the goal of 100 % renewable electricity supply. This work reviews the current ambitions of the Cuban government and provides a scientific approach to identifying the most cost-effective 100 % renewable energy system in 2030. First, we study whether the generation mix proposed by the Cuban government to reach 37 % renewables is the most cost-effective. Second, we run a simulation that considers fossil and renewable energy technologies purely to optimize costs. Third, we investigate the renewable future for Cuba with a simulation under the constraint of a 100 % renewable energy share. Our results suggest that energy sector plans should be reconsidered from a techno-economic point of view: With the overall cost-optimization, we find that much higher renewable energy shares of over 80 % are possible at lower overall costs. Finally, we analyze that the cost viability of a 100 % renewable electricity depends largely on the ability to use Cuba's biomass resources to balance solar generation.

The wind-solar hybrid energy could serve as a stable power source at multiple time scale in China mainland

The instability of wind and solar power hinders their penetration into electrical transmission networks. Hybrid wind-solar power generation can mitigate the instability of wind or solar power. However, research on complementary methods and the temporal distribution of wind and solar energies remains insufficient. In this study, well-validated and used high-resolution reanalysis data were used to explore the complementarity between wind and solar power on multiple time scales across China mainland. Researchers have found that wind and solar energies are strongly complementary from seasonal to hourly time scales. Wind-solar hybrid power generation can increase the availability of renewable energy by 15%–25 %, and a continuous renewable power supply can be achieved during daytime hours. In addition, the authors found that the complementary strength between wind and solar power could be enhanced by adjusting their proportions. This study highlights that hybrid wind-solar systems can provide a stable energy source. The complementary deployment of wind and solar energies should be considered in future applications.

P2M systems based on proton-conducting solid oxide cells: Future prospects and costs of renewable methanol production

As consequence of the transition towards sustainable energy sources, the future production of liquid energy carriers (e.g. methanol) via H2 supply pathways utilizing water electrolyzers (power-to-liquid) will most likely be based on fluctuating grid electricity or islanded renewable inputs. As a result, these production processes are subject to fluctuating operating conditions and varying production capacities, ultimately leading to uncertainties with respect to their process economics and profitability. Therefore, the impact of different electricity supply-side scenarios (static grid and intermittent grid or renewable supply) on the production economics of power-to-liquid processes needs to be assessed thoroughly for the upcoming decades. Methanol is considered as an essential base chemical which is widely known for its versatility and broad potential use contexts in future chemical industries and energy storage applications. Methanol production pathways powered by renewable electricity sources, also known as power-to-methanol processes, are characterized by low specific life-cycle emissions and are therefore of paramount interest. One possible renewable process chain features proton-conducting high temperature electrolyzers combined with a direct hydrogenation of CO2. In this paper, a techno-economic forecast study of this process chain is presented and specific production costs of renewable methanol under different electricity supply scenarios are determined and discussed for the years 2030 and 2050. The studies showed that flexible grid-supported scenarios through direct spot-market participation and renewable scenarios based on wind onshore production enable the largest production cost reduction potential in the upcoming decades. Minimum production costs of 740 € t−1MeOH (2030) and 415 € t−1MeOH (2050) are determined for a flexible operation of the system with spot-market participation, benefitting from times of low or even negative electricity prices. Among the renewable production scenarios, islanded power-to-methanol systems coupled to wind onshore plants were identified as the most beneficial configuration with ascertained production costs as low as 820 € t−1MeOH and 353 € t−1MeOH by 2030 and 2050, respectively.

Sustainable renewable energy supply chain with current technological adaptation: Macro energy progress policy in Iran

AbstractClimate change is a global challenge today that has been highly considered due to the wide impacts on different sectors of a society. That is why the use of renewable energy for countries and communities should be considered. In addition, the limitation of fossil fuels and the problems incurred by greenhouse gas emissions have made it increasingly important to make renewable energy more attractive. Sustainable energy means continuous supply of energy for today's needs without compromising the ability of future generations to meet their needs. Sustainable energy technologies include renewable energy sources such as hydroelectric power, solar energy, wind energy, geothermal energy, synthetic photo center and wave energy, as well as technologies designed to improve energy efficiency. Thus, this article discusses the development and performance of renewable supply chain energy in Iran. A strategic model is proposed and investigated to cover various aspects of sustainable renewable energy within a supply chain configuration integrated with machine learning method for quantification purpose. The novelty is on integrating machine learning and strategic plan to handle sustainability indicators within a renewable energy supply chain. The study also provides managerial insights to governments, researchers and stakeholders for the initiation of renewable energy use and suggestions for overcoming the barriers to its developments.

Optimal capacity and multi-stable flexible operation strategy of green ammonia systems: Adapting to fluctuations in renewable energy

The potential of power-to-ammonia is increasingly recognized as a large-scale renewable electrical energy storage technology in the energy-transition landscape. Unlike conventional, continuously operating Haber-Bosch production processes, power-to-ammonia processes face operational challenges stemming from fluctuations in renewable power supply. Systematic strategies that can adapt to these fluctuations are required to improve the operational flexibility and stability of power-to-ammonia processes for industrial applications. This study proposes a multi-stable flexible ammonia operation strategy, which is practical and feasible in engineering. To maximize net profit, a design scheduling coordination optimization model is established and solved using a two-stage algorithmic framework of particle swarm and mixed integer linear programming. Additionally, three flexible scenarios are designed for the simulation analysis of a grid-connected green ammonia system. Compared with the traditional constant inflexible scenario, the multi-stable flexible scenario increases annual net profit by 5.05 M$ and reduces carbon emission intensity by 1.61 kg CO2/kgNH3. Furthermore, compared with the continuous flexible scenario, the volatility of the ammonia production load is reduced by 79.89 %. The multi-stable flexible operation strategy balances the green ammonia system’s economic, safety, and low-carbon attributes. Sensitivity analysis reveals that wind and photovoltaic complementary power generation reduces green ammonia costs and carbon emissions. When the selling price of ammonia exceeds 550 $/t, ammonia production and sales should be prioritized, but at lower ammonia prices, selling electricity to the grid to optimize economic efficiency is advised. This study provides novel insights into the flexible operation of the power-to-ammonia process and is expected to offer guidance for constructing and operating green ammonia systems.

A data-driven optimization model for renewable electricity supply chain design

The rising electricity demand, driven by technological progress and population growth, has made the design of the electricity supply chain a major challenge. The transition to renewable energy sources has led to a substantial reduction in the costs and greenhouse gases emissions of electricity production. This study proposes a hybrid approach consisting of a recurrent neural network and an optimization model for designing a resilient electricity supply chain based on wind and solar energies. First, the electricity demand is forecast using the long short-term memory algorithm. Second, based on the forecast demand, a two-stage stochastic programming model is developed for designing an electricity supply chain under disruption risks. Partial and complete disruptions in power lines and facilities, including power plants, distribution and subtransmission substations, and low-power solar panel farms are considered. The objective of the proposed model is to minimize the total cost of the supply chain by making optimal decisions on facility location; technology selection for power plants; setting up transmission lines; and the quantity of power generation, power transmission, and power shortage in low- and high-voltage energy consumption systems. Three strategies are adopted to enhance the supply chain's resilience: multiple renewable energy sources, multiple power transmission lines, and lateral power lines. Lastly, the Sistan and Baluchestan Electric Power Distribution Company in Iran is used as a case study for this work to demonstrate the applicability of the proposed approach, analyze the findings, and derive relevant managerial insights.

Effects of direct and indirect electrification on transport energy demand during the energy transition

The global transport sector is one of the main sources of anthropogenic greenhouse gas emissions representing one quarter of all energy related greenhouse gas emissions. Defossilisation of the transport is an important part of the transition towards a carbon-neutral energy system. Fast development of electric mobility technologies, fast growth of renewable electricity generation and emerging power-to-fuels sector provide the means for such a transition. The transition simulation presented in this study focuses on the transport sector using an energy system model in hourly resolution and the transition reaches 100% renewable energy supply by 2050. Results show that massive electrification emerges as the main path for the transport sector, while in some segments, where direct electrification is not possible, demand is satisfied with renewable electricity-based fuels. In every region of the world, the existing renewable energy potential is more than sufficient to satisfy the transport sector demand even with fast growth. The transition leads to significant improvement in energy efficiency both on the demand side, due to more efficient engines and electric motors, and the supply side, with the switch to renewable electricity supply. Solar photovoltaics evolve to become the main source of energy for the transport sector by mid-century.

Characterizing the multisectoral impacts of future global hydrologic variability

There is significant uncertainty in how global water supply will evolve in the future, due to uncertain climate, socioeconomic, and land use change drivers and variability of hydrologic processes. It is critical to characterize the potential impacts of uncertainty in future water supply given its importance for food and energy production. In this work, we introduce a framework that integrates stochastic hydrology and human-environmental systems to characterize uncertainty in future water supply and its multisector impacts. We develop a global stochastic watershed model and demonstrate that this model can generate a large ensemble of realizations of basin-scale runoff with global coverage that preserves the mean, variance, and spatial correlation of a historical benchmark. We couple this model with a well-known human-environmental systems model to explore the impacts of runoff variability on the water and agricultural sectors across spatial scales. We find that the impacts of future hydrologic variability vary across sectors and regions. Impacts are felt most strongly in the water and agricultural sectors for basins that are expected to have unsustainable water use in the future, such as the Indus River basin. For this basin, we find that the variability in future irrigation water withdrawals and irrigated cropland increase over time due to uncertainty in renewable water supply. We also use the Indus basin to show how our stochastic ensemble can be leveraged to explore the global multisector consequences of local extreme runoff conditions. This work introduces a novel technique to explore the propagation of future hydrologic variability across human and natural systems and spatial scales.