Hasil untuk "Renewable energy sources"

Noah Kittner, F. Lill, D. Kammen

O. Gutfleisch, M. Willard, E. Brück et al.

P. D’Odorico, K. Davis, L. Rosa et al.

Water availability is a major factor constraining humanity's ability to meet the future food and energy needs of a growing and increasingly affluent human population. Water plays an important role in the production of energy, including renewable energy sources and the extraction of unconventional fossil fuels that are expected to become important players in future energy security. The emergent competition for water between the food and energy systems is increasingly recognized in the concept of the “food‐energy‐water nexus.” The nexus between food and water is made even more complex by the globalization of agriculture and rapid growth in food trade, which results in a massive virtual transfer of water among regions and plays an important role in the food and water security of some regions. This review explores multiple components of the food‐energy‐water nexus and highlights possible approaches that could be used to meet food and energy security with the limited renewable water resources of the planet. Despite clear tensions inherent in meeting the growing and changing demand for food and energy in the 21st century, the inherent linkages among food, water, and energy systems can offer an opportunity for synergistic strategies aimed at resilient food, water, and energy security, such as the circular economy.

Tao Hong, P. Pinson, Yi Wang et al.

Forecasting has been an essential part of the power and energy industry. Researchers and practitioners have contributed thousands of papers on forecasting electricity demand and prices, and renewable generation (e.g., wind and solar power). This article offers a brief review of influential energy forecasting papers; summarizes research trends; discusses importance of reproducible research and points out six valuable open data sources; makes recommendations about publishing high-quality research papers; and offers an outlook into the future of energy forecasting.

F. Ahmed, Raed Hashaikeh, N. Hilal

Abstract Growing water demands have led to rapidly increasing desalination installation capacity worldwide. In an attempt to lower carbon footprint resulting from high-energy consuming desalination processes, attention has shifted to using renewable energy sources to power desalination. With solar irradiation ample in regions that heavily rely on desalination, solar powered desalination provides a sustainable solution to meeting water needs. The compatibility of each desalination process with the solar technology is driven by whether the kind of energy needed is thermal or electrical, as well as its availability. With rapid advances in solar energy technologies – both photovoltaic and solar thermal, there has also been growing interest in coupling solar energy with desalination, with a focus on improving energy efficiency. In this review, the most recent developments in photovoltaic powered reverse osmosis (PV-RO), solar thermal powered reverse osmosis (ST-RO) are discussed with respect to membrane materials, process configuration, energy recovery devices and energy storage. In addition, advances in new materials for solar powered membrane distillation (MD) and solar stills in the past two years have also been reviewed. Future outlook considers the use of hybrid renewable energy systems as well as solar powered forward osmosis and dewvaporation. Solar powered desalination systems have been analysed with emphasis on technological and energy consumption aspects.

P. Vesborg, T. Jaramillo

The energy infrastructure for fossil fuels is well-established, accounting for approximately 87% of the 16 TW of power consumed globally. For renewable and sustainable energy conversion technologies to play a relevant role at the terrestrial scale, they must be able to scale to the TW level of deployment. This would place a significant demand on the current and future supply of raw materials (chemical elements) used by those technologies. Oftentimes, the average crustal abundance of a chemical element is cited as a measure of its scalability, however another important metric for scalability is the existence (of lack thereof) of mineable ores with a high concentration of the targeted element. This paper aims to provide an overview of the availability of all elements. This is accomplished via a compilation of data for global primary production rates for each element, as a measure of availability at the present time. This work also addresses the potential future availability based on current and possible future primary sources.

A. Menegaki

Richard York, S. Bell

Abstract Is an energy transition currently in progress, where renewable energy sources are replacing fossil fuels? Previous changes in the proportion of energy produced by various sources – such as in the nineteenth century when coal surpassed biomass in providing the largest share of the global energy supply and in the twentieth century when petroleum overtook coal – could more accurately be characterized as energy additions rather than transitions. In both cases, the use of the older energy source continued to grow, despite rapid growth in the new source. Evidence from contemporary trends in energy production likewise suggest that as renewable energy sources compose a larger share of overall energy production, they are not replacing fossil fuels but are rather expanding the overall amount of energy that is produced. We argue that although it is reasonable to expect that renewables will come to provide a growing share of the global energy supply, it is misleading to characterize this growth in renewable energy as a “transition” and that doing so could inhibit the implementation of meaningful policies aimed at reducing fossil fuel use.

M. Argyrou, P. Christodoulides, S. Kalogirou

Renewable Energy Sources have been growing rapidly over the last few years. The spreading of renewables has become stronger due to the increased air pollution, which is largely believed to be irreversible for the environment. On the other hand, the penetration of renewable energy technologies causes major problems to the stability of the grid. Along with the fluctuations of the renewable energy technologies production, storage is important for power and voltage smoothing. Energy storage is also important for energy management, frequency regulation, peak shaving, load leveling, seasonal storage and standby generation during a fault. Thus, storage technologies have gained an increased attention and have become more than a necessity nowadays. This paper presents an up to date comprehensive overview of energy storage technologies. It incorporates characteristics and functionalities of each storage technology, as well as their advantages and disadvantages compared with other storage technologies. Comparison tables with several characteristics of each storage method are included, while different applications of energy storage technologies are described as well. Finally, several hybrid energy storage applications are analyzed and different combinations of energy storage technologies are reviewed.

J. Lim, Z. Manan, S. R. Alwi et al.

Wei Wu, H. Skye

Advancements in residential net-zero energy buildings (NZEBs) could significantly reduce energy consumption and greenhouse gas emissions. NZEB design considerations broadly categorize into energy infrastructure connections, renewable energy sources, and energy-efficiency measures. There is a lack of systematic literature review focused on recent progress in residential NZEBs. Therefore, this work provides an overview of each category including recent developments (last ≈ 10 years), aiming to provide references and support of wider and more successful implementation of residential NZEBs throughout the globe. The discussed energy infrastructure connections include electrical grids, district heating/cooling networks, and energy storage options including vehicle-to-home and hydrogen storage. Renewable energy sources considered here are solar photovoltaic and solar thermal, wind, and biomass including micro combined heat and power (CHP) systems. The final category detailed is energy-efficiency measures, which include improved building envelope designs, efficient HVAC systems, efficient domestic hot water systems, and phase change material integration. Within these categories there are many technology options, which makes selecting the 'best' configuration more difficult but allows design flexibility to adapt to local climates and other considerations (i.e. building codes, energy resources, costs). This paper provides references and highlights technology options to achieve residential NZEBs throughout the world.

M. Rabbi, J. Popp, D. Máté et al.

Successful energy transitions, also referred to as leapfrog development, present enormous prospects for EU nations to become carbon neutral by shifting from fossil fuels to renewable energy sources. Along with climate change, EU countries must address energy security and dependency issues, exacerbated by factors such as the COVID-19 pandemic, rising energy costs, conflicts between Russia and Ukraine, and political instability. Diversifying energy sources, generating renewable energy, increasing energy efficiency, preventing energy waste, and educating the public about environmental issues are proposed as several strategies. The study draws the conclusion that central European countries may transition to a clean energy economy and become carbon neutral on economic and strategic levels by locating alternative clean energy supply sources, reducing energy use, and producing renewable energy. According to the study, the EU energy industry can be decarbonised and attain energy security using three basic strategies, such as supply diversification, energy savings, and quicker adoption of renewable energy to replace fossil fuels. The energy transformation industry still needs to improve energy efficiency, incorporate a circular and sustainable bioeconomy, and support renewable energies, including solar, wind, hydropower, nuclear, and hydrogen.

O. Hafez, Kankar Bhattacharya

Najwa Syahirah Mohamed Nor Izam, Z. Itam, W. Sing et al.

This study examines the sources of energy related carbon dioxide (CO2) emissions, the hazards of climate change and greenhouse gas (GHG) emissions, the global solar energy potential, renewable energy sustainability indicators, impediments, and the environmental implications of fossil fuels. The purpose of this study is to investigate viewpoints on solar energy technologies for sustainable development, with a particular emphasis on photovoltaic (PV), as well as the literature on solar energy technology performance, in order to ascertain worldwide solar energy adoption trends. The discussions address the solar industry’s fundamental ideas, the global energy scenario, the highlights of research conducted to improve the solar industry, prospective applications and future challenges for a more efficient solar industry that may help alleviate the energy crisis. A review of the framework and development of Renewable Energy Sources (RES) and Renewable Energy Laws (REL) on a global scale was conducted.

Yongfang Xia, Xiaohu Guan, Xiangyang Zhou et al.

As a multiple-energy carrier, hydrogen can facilitate the transition to a low-carbon future, and coupling renewable energy sources with hydrogen-power generation systems (e.g., gas turbines) can markedly enhance gas turbine combined cycles (GTCCs) power generation regarding cleanliness and flexibility. Conventional gas turbines fuel the natural gas–hydrogen mixture and encounter issues like unstable combustion and elevated nitrogen oxide (NO_x) emissions. Initially, the alterations in combustion characteristics resulting from the fuel transition are analyzed, and the principal technical challenges of hydrogen-mixed combustion are summarized. It is found that hydrogen exhibits a laminar flame speed approximately 7–10 times higher than that of methane, and a hydrogen blending ratio beyond 30% significantly increases the risk of flashback and thermoacoustic oscillations. The existing technical proficiencies of advanced hydrogen combustion strategies are delineated to offer decision-making assistance for the industry. For instance, micromix combustors can achieve NOx emissions below 20 ppm even with 100% hydrogen, while axial staging technology expands the stable operating range to 25–106% load. Additionally, current research on hydrogen-fueled gas turbines primarily focuses on enhancing traditional combustor designs. Conversely, the focus on the overall alteration of gas turbines has been relatively restricted. It further examines component failure issues arising from elevated temperatures and material hydrogen embrittlement, highlighting that X80 pipeline steel experiences a 17-fold increase in hydrogen embrittlement index when the hydrogen blending ratio rises from 1% to 20%, as well as safety concerns related to fuel transitions from conventional gas turbines to hydrogen gas turbines, offering technical references for the comprehensive optimization of hydrogen-fueled gas turbines.

Florian List, Yujin Park, Nicholas L. Rodd et al.

The Galactic Center Excess (GCE) remains one of the defining mysteries uncovered by the Fermi $γ$-ray Space Telescope. Although it may yet herald the discovery of annihilating dark matter, weighing against that conclusion are analyses showing the spatial structure of the emission appears more consistent with a population of dim point sources. Technical limitations have restricted prior analyses to studying the point-source hypothesis purely spatially. All spectral information that could help disentangle the GCE from the complex and uncertain astrophysical emission was discarded. We demonstrate that a neural network-aided simulation-based inference approach can overcome such limitations and thereby confront the point source explanation of the GCE with spatial and spectral data. The addition is profound: energy information drives the putative point sources to be significantly dimmer, indicating either the GCE is truly diffuse in nature or made of an exceptionally large number of sources. Quantitatively, for our best fit background model, the excess is essentially consistent with Poisson emission as predicted by dark matter. If the excess is instead due to point sources, our median prediction is ${\cal O}(10^5)$ sources in the Galactic Center, or more than 35,000 sources at 90% confidence, both significantly larger than the hundreds of sources preferred by earlier point-source analyses of the GCE.

Sebastian Kebrich, Felix Engelhardt, David Franzmann et al.

Future greenhouse gas neutral energy systems will be dominated by renewable energy technologies providing variable supply subject to uncertain weather conditions. For this setting, we propose an algorithm for capacity expansion planning: We evaluate solutions optimised on a single years' data under different input weather years, and iteratively modify solutions whenever supply gaps are detected. These modifications lead to solutions with sufficient capacities to overcome periods of cold dark lulls and seasonal demand/supply fluctuations. A computational study on a German energy system model for 40 operating years shows that preventing supply gaps, i.e. finding a robust system, increases the total annual cost by 1.6-2.9%. In comparison, non-robust systems display loss of load close to 50% of total demand during some periods. Results underline the importance of assessing the feasibility of energy system models using atypical time-series, combining dark lull and cold period effects.

Gianni Bianchini, Marco Casini, Milad Gholami

Within the context of renewable energy communities, this paper focuses on optimal operation of producers equipped with energy storage systems in the presence of demand response. A novel strategy for optimal scheduling of the storage systems of the community members under price-volume demand response programs, is devised. The underlying optimization problem is designed as a low-complexity mixed-integer linear program that scales well with the community size. Once the optimal solution is found, an algorithm for distributing the demand response rewards is introduced in order to guarantee fairness among participants. The proposed approach ensures increased benefits for producers joining a community compared to standalone operation.

Fulong Yao, Wanqing Zhao, Matthew Forshaw

Predictive control approaches based on deep reinforcement learning (DRL) have gained significant attention in microgrid energy optimization. However, existing research often overlooks the issue of uncertainty stemming from imperfect prediction models, which can lead to suboptimal control strategies. This paper presents a new error temporal difference (ETD) algorithm for DRL to address the uncertainty in predictions,aiming to improve the performance of microgrid operations. First,a microgrid system integrated with renewable energy sources (RES) and energy storage systems (ESS), along with its Markov decision process (MDP), is modelled. Second, a predictive control approach based on a deep Q network (DQN) is presented, in which a weighted average algorithm and a new ETD algorithm are designed to quantify and address the prediction uncertainty, respectively. Finally, simulations on a realworld US dataset suggest that the developed ETD effectively improves the performance of DRL in optimizing microgrid operations.

Jingnan Wang, Jie Chao, Shangshang Yang et al.

The planning and operation of renewable energy, especially wind power, depend crucially on accurate, timely, and high-resolution weather information. Coarse-grid global numerical weather forecasts are typically downscaled to meet these requirements, introducing challenges of scale inconsistency, process representation error, computation cost, and entanglement of distinct uncertainty sources from chaoticity, model bias, and large-scale forcing. We address these challenges by learning the climatological distribution of a target wind farm using its high-resolution numerical weather simulations. An optimal combination of this learned high-resolution climatological prior with coarse-grid large scale forecasts yields highly accurate, fine-grained, full-variable, large ensemble of weather pattern forecasts. Using observed meteorological records and wind turbine power outputs as references, the proposed methodology verifies advantageously compared to existing numerical/statistical forecasting-downscaling pipelines, regarding either deterministic/probabilistic skills or economic gains. Moreover, a 100-member, 10-day forecast with spatial resolution of 1 km and output frequency of 15 min takes < 1 hour on a moderate-end GPU, as contrast to $\mathcal{O}(10^3)$ CPU hours for conventional numerical simulation. By drastically reducing computational costs while maintaining accuracy, our method paves the way for more efficient and reliable renewable energy planning and operation.