Showing papers on "Renewable energy published in 2018"
TL;DR: In this paper, the merits and demerits of solar energy technologies are both discussed and a number of technical problems affecting renewable energy research are also highlighted, along with beneficial interactions between regulation policy frameworks and their future prospects.
Abstract: The development of novel solar power technologies is considered to be one of many key solutions toward fulfilling a worldwide increasing demand for energy. Rapid growth within the field of solar technologies is nonetheless facing various technical barriers, such as low solar cell efficiencies, low performing balance-of-systems (BOS), economic hindrances (e.g., high upfront costs and a lack of financing mechanisms), and institutional obstacles (e.g., inadequate infrastructure and a shortage of skilled manpower). The merits and demerits of solar energy technologies are both discussed in this article. A number of technical problems affecting renewable energy research are also highlighted, along with beneficial interactions between regulation policy frameworks and their future prospects. In order to help open novel routes with regard to solar energy research and practices, a future roadmap for the field of solar research is discussed.
1,331 citations
TL;DR: In this paper, the authors present the concept of a blockchain-based microgrid energy market without the need for central intermediaries, where consumers and prosumers can trade self-produced energy in a peer-to-peer fashion.
1,010 citations
TL;DR: This article explored the relationship between economic growth and CO2 emissions in the so-called European Union 5 (EU-5) countries (Germany, France, Italy, Spain, and the United Kingdom) for the 1985-2016 period.
796 citations
TL;DR: In this article, the key challenges that hydrogen industry are confronting are introduced and highlighted to facilitate the use of hydrogen as an alternative energy, which is considered a promising technique that can help manage hydrogen from food waste.
785 citations
TL;DR: An overview of the development and perspectives of biogas in and its use for electricity, heat and in transport in the European Union (EU) and its Member States is presented in this article.
755 citations
TL;DR: In this paper, the authors developed a narrative of future change based on observable trends that results in low energy demand and showed how changes in the quantity and type of energy services drive structural change in intermediate and upstream supply sectors (energy and land use).
Abstract: Scenarios that limit global warming to 1.5 °C describe major transformations in energy supply and ever-rising energy demand. Here, we provide a contrasting perspective by developing a narrative of future change based on observable trends that results in low energy demand. We describe and quantify changes in activity levels and energy intensity in the global North and global South for all major energy services. We project that global final energy demand by 2050 reduces to 245 EJ, around 40% lower than today, despite rises in population, income and activity. Using an integrated assessment modelling framework, we show how changes in the quantity and type of energy services drive structural change in intermediate and upstream supply sectors (energy and land use). Down-sizing the global energy system dramatically improves the feasibility of a low-carbon supply-side transformation. Our scenario meets the 1.5 °C climate target as well as many sustainable development goals, without relying on negative emission technologies. Achieving sustainable development goals while meeting the 1.5 °C climate target requires radical changes to how we use energy. A scenario of low energy demand shows how this can be done by down-sizing the global energy system to enable feasible deployment rates of renewable energy resources.
680 citations
TL;DR: This work provides energy prosumers and consumers with a decentralized market platform for trading local energy generation without the need of a central intermediary and presents a preliminary economic evaluation of the market mechanism and a research agenda for the technological evaluation of blockchain technology as the local energy market’s main information and communication technology.
Abstract: The increasing amount of renewable energy sources in the energy system calls for new market approaches to price and distribute the volatile and decentralized generation. Local energy markets, on which consumers and prosumers can trade locally produced renewable generation directly within their community, balance generation and consumption locally in a decentralized approach. We present a comprehensive concept, market design and simulation of a local energy market between 100 residential households. Our approach is based on a distributed information and communication technology, i.e. a private blockchain, which underlines the decentralized nature of local energy markets. Thus, we provide energy prosumers and consumers with a decentralized market platform for trading local energy generation without the need of a central intermediary. Furthermore, we present a preliminary economic evaluation of the market mechanism and a research agenda for the technological evaluation of blockchain technology as the local energy market’s main information and communication technology.
628 citations
TL;DR: In this paper, a comprehensive and systematic review of the direct forecasting of PV power generation is presented, where the importance of the correlation of the input-output data and the preprocessing of model input data are discussed.
Abstract: To mitigate the impact of climate change and global warming, the use of renewable energies is increasing day by day significantly. A considerable amount of electricity is generated from renewable energy sources since the last decade. Among the potential renewable energies, photovoltaic (PV) has experienced enormous growth in electricity generation. A large number of PV systems have been installed in on-grid and off-grid systems in the last few years. The number of PV systems will increase rapidly in the future due to the policies of the government and international organizations, and the advantages of PV technology. However, the variability of PV power generation creates different negative impacts on the electric grid system, such as the stability, reliability, and planning of the operation, aside from the economic benefits. Therefore, accurate forecasting of PV power generation is significantly important to stabilize and secure grid operation and promote large-scale PV power integration. A good number of research has been conducted to forecast PV power generation in different perspectives. This paper made a comprehensive and systematic review of the direct forecasting of PV power generation. The importance of the correlation of the input-output data and the preprocessing of model input data are discussed. This review covers the performance analysis of several PV power forecasting models based on different classifications. The critical analysis of recent works, including statistical and machine-learning models based on historical data, is also presented. Moreover, the strengths and weaknesses of the different forecasting models, including hybrid models, and performance matrices in evaluating the forecasting model, are considered in this research. In addition, the potential benefits of model optimization are also discussed.
626 citations
TL;DR: A comparative and critical analysis on decision making strategies and their solution methods for microgrid energy management systems are presented and various uncertainty quantification methods are summarized.
617 citations
TL;DR: In this paper, the authors compared different water electrolysis processes, i.e., alkaline water, proton exchange membrane, solid oxide water, and anion exchange membrane water.
605 citations
TL;DR: It becomes clear that the critical metrics for battery sizing, and by extension the most suitable method for determining battery size, are determined by the type of renewable energy system application, as well as its size.
Abstract: Renewable energy, such as hydro power, photovoltaics and wind turbines, has become the most widely applied solutions for addressing issues associated with oil depletion, increasing energy demand and anthropogenic global warming. Solar and wind energy are strongly dependent on weather resources with intermittent and fluctuating features. To filter these variabilities, battery energy storage systems have been broadly accepted as one of the potential solutions, with advantages such as fast response capability, sustained power delivery, and geographical independence. During the implementation of battery energy storage systems, one of the most crucial issues is to optimally determine the size of the battery for balancing the trade-off between the technical improvements brought by the battery and the additional overall cost. Numerous studies have been performed to optimise battery sizing for different renewable energy systems using a range of criteria and methods. This paper provides a comprehensive review of battery sizing criteria, methods and its applications in various renewable energy systems. The applications for storage systems have been categorised based on the specific renewable energy system that the battery storage will be a part. This is in contrast to previous studies where the battery sizing approaches were either arranged as an optimised component in renewable systems or only accounted for one category of renewable system. By taking this approach, it becomes clear that the critical metrics for battery sizing, and by extension the most suitable method for determining battery size, are determined by the type of renewable energy system application, as well as its size. This has important implications for the design process as the renewable energy system application will drive the battery energy storage system sizing methodology chosen.
TL;DR: In light of the targets set out by the Paris Climate Agreement and the global energy sector's ongoing transition from fossil fuels to renewables, the chemical industry is searching for innovative ways of reducing greenhouse gas emissions associated with the production of ammonia as discussed by the authors.
03 Mar 2018
TL;DR: In this article, the authors present the recent progresses and challenges in discovery of high-performance anode materials for Li-ion batteries related to their applications in future electrical vehicles and grid energy storage.
Abstract: Transformational changes in battery technologies are critically needed to enable the effective use of renewable energy sources, such as solar and wind, and to allow for the expansion of the electrification of vehicles. Developing high-performance batteries is critical to meet these requirements, which certainly relies on material breakthroughs. This review article presents the recent progresses and challenges in discovery of high-performance anode materials for Li-ion batteries related to their applications in future electrical vehicles and grid energy storage. The advantages and disadvantages of a series of anode materials are highlighted.
TL;DR: In this paper, the authors reviewed the sources of energy-related emissions, risks of climate change, global solar energy potential, sustainability indicators of renewable energies, environmental impacts of fossil fuels and renewable energies and benefits of solar energy utilization.
Abstract: The growing global demand for energy from fossil fuels plays a key role in the upward trend in greenhouse gas (GHG) emissions and air pollutants. Rapid population growth and increasing energy demand in the developing countries have brought many concerns such as poverty, pollution, health and environmental problems. While for these countries, particularly the poorest ones, modern energy is necessary to stimulate production, income generation and social development plus reduce the serious health issues that are caused by the use of fuelwood, charcoal, animal dung and agricultural waste. Solar energy is the best answer to energy poverty and it can provide excellent opportunities for reduction of GHG emissions and indoor air pollution through substituting kerosene for lighting and firewood for cooking. Solar photovoltaic (PV) can be an appropriate technology for a source of renewable electricity in developing nations especially in remote rural areas where grid extensions are financially or technically not viable. PV can also be used to reduce demand for fossil fuels and associated emissions, including carbon dioxide (CO2), nitrogen oxides (NOx) and sulfur dioxide (SO2). The use of PV systems can reduce 69–100 million tons of CO2, 126,000–184,000 t of SO2 and 68,000–99,000 t of NOx by 2030. In case countries use concentrating solar power (CSP) systems, each square meter of concentrator surface is enough to save about 200–300 kg (kg) of CO2 emissions annually. Although there are excellent renewable opportunities in many developing countries, several key barriers have prevented large-scale deployment of solar energy technologies in these countries. This study reviews the sources of energy-related emissions, risks of climate change, global solar energy potential, sustainability indicators of renewable energies, environmental impacts of fossil fuels and renewable energies, benefits of solar energy utilization. It also discusses barriers to widespread use of solar energy.
TL;DR: In this paper, the potential of carbon capture and utilisation (CCU) is assessed focusing on the use of CO2 for fuel as well as for combined heat and power production.
Abstract: The continuously increasing share of Renewable Energy Sources (RES) and EU targets for CO2 reduction and energy efficiency necessitate significant changes both on technical and regulatory level. Environmental challenges of CO2 emissions are assessed in a review of CO2 capture and utilisation technologies, offering new opportunities in CO2 economy. Commercial applications in the thermal power and industrial sector for pre and post combustion capture as well as the potential of direct air CO2 capture are reviewed. The potential of Carbon Capture and Utilisation (CCU) is assessed focusing on the use of CO2 for fuel as well as for combined heat and power production. Combining CCU with energy storage as an evolutionary measure for balancing RES with thermal power under the power to fuel concept presents high market potentials for fuel and chemical production. Moreover, the recent progress in supercritical CO2 cycles for combined heat and power production is reported.
TL;DR: In this article, the photothermal effect has been used as a novel strategy to augment vaporization and catalysis performance, and the design of efficient photothermal conversion materials in terms of both light harvesting and thermal management.
Abstract: Solar energy is a major source of renewable energy with the potential to meet the energy demand and to support the sustainable development of the world. The efficient harvesting and conversion of solar energy is one of the key factors to maximize the utilization of solar energy. In general, solar energy can be harnessed and converted into various kinds of energy, including electricity, fuels and thermal energy, through photovoltaic, photochemical and photothermal processes, respectively. Among these technologies, photothermal conversion is a direct conversion process that has attained the highest achievable conversion efficiency. The photothermal effect has been used as a novel strategy to augment vaporization and catalysis performance. In this review, we look into the basis of the photothermal conversion process, the design of efficient photothermal conversion materials in terms of both light harvesting and thermal management, a fundamental understanding of various system schemes, and the recent progress in photothermal evaporation and catalysis applications. This review aims to afford researchers with a better understanding of the photothermal effect and provide a guide for the rational design and development of highly efficient photothermal materials in energy and environmental fields.
TL;DR: In this paper, the authors considered both cross-sector and cross-border integration in the model PyPSA-Eur-Sec-30, the first open, spatially-resolved, temporally resolved and sector-coupled energy model of Europe, and calculated the cost-optimal system for a 95% reduction in carbon dioxide emissions compared to 1990, incorporating electricity, transport and heat demand.
TL;DR: A review of micro-algal biofuel production potential and possible ways to put it into practice can be found in this article, with particular emphasis on Scenedesmus obliquus, a type of algae that can efficiently convert sunlight, water and CO2 into a variety of products suitable for renewable energy applications.
Abstract: The rapid growth of human population has led to mounting energy demands, which is projected to increase by 50% or more by 2030. The natural petroleum can not catch-up the current consumption rate, which is already reported to be 105 times faster than nature can create. Besides, the use of fossil fuels is devastating to our environment through greenhouse gas emissions and consequent global warming. Therefore, the search for ‘clean’ energy has become the most overwhelming challenges. Currently, several alternatives are being studied and implemented. Biofuels, fuels from living organisms, provide environmental benefits, since their use leads to a decrease in the harmful emissions of CO2 and hydrocarbons and, to the elimination of SOx emissions, with a consequent decrease in the greenhouse effects. Unfortunately, the present biofuel projections are based on feed-stocks that are also food commodities and resources suitable for conventional agriculture. One possibility to overcome the problem is the cultivation of micro-algae and switching to third generation biofuels, which seem to be a promising source since algae are able to efficiently convert sunlight, water, and CO2 into a variety of products suitable for renewable energy applications. Therefore, this review is intended to recapitulate current works on micro-algal biofuel production potential and discuss possible ways to put it into practice. This review starts by highlighting the advantages and various forms of micro-algal biofuels. Some of the micro-algal species proved to be suitable for biofuel production so far are considered, with particular emphasis on Scenedesmus obliquus. The recent attempts and achievements in improving the economies of production through genetic and metabolic engineering of micro-algal strains are also addressed. Other potential applications such as wastewater treatment and CO2 mitigation that can be coupled with biofuel production are described. Finally, the promises and challenges of algae to biofuel industry are uncovered.
TL;DR: In this paper, a review of more than 60 studies (plus m4ore than 65 studies on P2G) on power and energy models based on simulation and optimization was done, based on these, for power systems with up to 95% renewables, the electricity storage size is found to be below 1.5% of the annual demand (in energy terms).
Abstract: A review of more than 60 studies (plus m4ore than 65 studies on P2G) on power and energy models based on simulation and optimization was done. Based on these, for power systems with up to 95% renewables, the electricity storage size is found to be below 1.5% of the annual demand (in energy terms). While for 100% renewables energy systems (power, heat, mobility), it can remain below 6% of the annual energy demand. Combination of sectors and diverting the electricity to another sector can play a large role in reducing the storage size. From the potential alternatives to satisfy this demand, pumped hydro storage (PHS) global potential is not enough and new technologies with a higher energy density are needed. Hydrogen, with more than 250 times the energy density of PHS is a potential option to satisfy the storage need. However, changes needed in infrastructure to deal with high hydrogen content and the suitability of salt caverns for its storage can pose limitations for this technology. Power to Gas (P2G) arises as possible alternative overcoming both the facilities and the energy density issues. The global storage requirement would represent only 2% of the global annual natural gas production or 10% of the gas storage facilities (in energy equivalent). The more options considered to deal with intermittent sources, the lower the storage requirement will be. Therefore, future studies aiming to quantify storage needs should focus on the entire energy system including technology vectors (e.g. Power to Heat, Liquid, Gas, Chemicals) to avoid overestimating the amount of storage needed.
TL;DR: In 2017, global CO2 emissions from burning fossil fuels reached 33 gigatons, twice the natural rate at which CO2 is absorbed back into land and ocean sinks as mentioned in this paper.
TL;DR: In this paper, the authors demonstrate a water-splitting reactor using a fixed Al-doped SrTiO 3 photocatalyst and address the key issues in the reactor design associated with the scaleup.
TL;DR: In this article, the authors estimate the determinants of CO2 emissions for the ten biggest electricity generators in Sub-Saharan Africa for the period 1980 to 2011 by employing panel estimation techniques robust to cross dependence.
TL;DR: In this paper, a review of previous studies, recent advances, and future directions on co-pyrolysis of biomass and waste plastics for high-grade biofuel production particularly in China and elsewhere worldwide is presented.
TL;DR: It is quantified how benefits exceed costs by a safe margin with the benefits of systems integration being the most important.
TL;DR: This work proposed a data-driven approach for scenario generation using generative adversarial networks, which is based on two interconnected deep neural networks that captures renewable energy production patterns in both temporal and spatial dimensions for a large number of correlated resources.
Abstract: Scenario generation is an important step in the operation and planning of power systems with high renewable penetrations. In this work, we proposed a data-driven approach for scenario generation using generative adversarial networks, which is based on two interconnected deep neural networks. Compared with existing methods based on probabilistic models that are often hard to scale or sample from, our method is data-driven, and captures renewable energy production patterns in both temporal and spatial dimensions for a large number of correlated resources. For validation, we use wind and solar times-series data from NREL integration data sets. We demonstrate that the proposed method is able to generate realistic wind and photovoltaic power profiles with full diversity of behaviors. We also illustrate how to generate scenarios based on different conditions of interest by using labeled data during training. For example, scenarios can be conditioned on weather events (e.g., high wind day, intense ramp events, or large forecasts errors) or time of the year (e.g., solar generation for a day in July). Because of the feedforward nature of the neural networks, scenarios can be generated extremely efficiently without sophisticated sampling techniques.
TL;DR: In this paper, the authors provide a review of the emergence of hydrogen within low-carbon pathways from different integrated energy system models, with drivers, marginal abatement costs and timing of hydrogen emergence assessed.
Abstract: This study provides a review of the emergence of hydrogen within low-carbon pathways from different integrated energy system models. The objective is to understand the drivers and policy scenarios that lead to the emergence of hydrogen over other low-carbon technologies. The review is divided into global, multi-regional and national integrated energy system models with drivers, marginal abatement costs and timing of hydrogen emergence assessed. Hydrogen's use in energy systems is complex as a result of its relationship with other energy sources. It was found that bioenergy can act as both a competitor and driver for hydrogen energy, along with increased electrification and high renewable electricity scenarios. However, electric vehicles are a main competitor in the passenger vehicle sector. In reviewed results, hydrogen mainly emerges after 2030; although, some technologies emerge as early as 2020 and as late as 2050. The uncertainty and complexity surrounding hydrogen may be as a result of the difficulty of representing hydrogen technologies and systems in energy system models. This study can allow policy makers to assess the various options to be considered regarding hydrogen and make informed decisions for moving towards a decarbonised energy system.
TL;DR: Graphene aerogels are promising materials for energy systems due to their porous hierarchical structure which affords rapid electron/ion transport, superior chemical and physical stability, and good cycle performance as discussed by the authors.
Abstract: Concerns over air quality reduction resulting from burning fossil fuels have driven the development of clean and renewable energy sources. Supercapacitors, batteries and solar cells serve as eco-friendly energy storage and conversion systems vitally important for the sustainable development of human society. However, many diverse elements influence the performance of energy storage and conversion systems. The overall efficiency of systems depends on the specific structure and properties of incorporated functional materials. Carbon materials, such as graphene, are especially promising for materials development in the energy storage and conversion fields. Graphene, a two-dimensional (2D) carbon material only a single atom thick, has massless Dirac fermions (electron transport is governed by Dirac's equation), displays outstanding electrical conductivity, superior thermal conductivity and excellent mechanical properties. 2D free-standing graphene films and powders have paved the way for promising energy applications. Recently, much effort has been spent trying to improve the number of active sites in electrode materials within 3D network/aerogel structures derived from graphene. This is because graphene aerogels are promising materials for energy systems due to their porous hierarchical structure which affords rapid electron/ion transport, superior chemical and physical stability, and good cycle performance. This review aims to summarize the synthetic methods, mechanistic aspects, and energy storage and conversion applications of novel 3D network graphene, graphene derivatives and graphene-based materials. Areas of application include supercapacitors, Li-batteries, H2 and thermal energy storage, fuel cells and solar cells.
TL;DR: In this article, a hybrid support vector machine (SVM) model was proposed to forecast both solar and wind energy resources for most of the locations in the United States, where the authors highlighted main problems, opportunities and future work in this research area.
TL;DR: In this paper, optimal sizing of a PV/wind/diesel HMS with battery storage is conducted using the Multi-Objective Self-Adaptive Differential Evolution (MOSaDE) algorithm for the city of Yanbu, Saudi Arabia using the multi-objective optimization approach.
TL;DR: In this article, the authors compared the level of CO2 emission caused by the construction activities globally by using the world environmental input-output table 2009 and analyzed CO2 emissions of construction sector in 40 countries, considering 26 kinds of energy use and non-energy use.
Abstract: The construction sector delivers the infrastructure and buildings to the society by consumption large amount of unrenewable energy. Consequently, this consumption causes the large emission of CO2. This paper explores and compares the level of CO2 emission caused by the construction activities globally by using the world environmental input-output table 2009. It analyses CO2 emission of construction sector in 40 countries, considering 26 kinds of energy use and non-energy use. Results indicate: 1) the total CO2 emission of the global construction sector was 5.7 billion tons in 2009, contributing 23% of the total CO2 emissions produced by the global economics activities. 94% of the total CO2 from the global construction sector are indirect emission. 2) Gasoline, diesel, other petroleum products and light fuel oil are four main energy sources for direct CO2 emission of global construction sector. The indirect CO2 emission mainly stems from hard coal, nature gas, and non-energy use. 3) The emerging economies cause nearly 60% of the global construction sector total CO2 emission. China is the largest contributor. Moreover, the intensities of construction sector’s direct and indirect CO2 emission in the developing countries are larger than the value in the developed countries. Therefore, promoting the development and use of the low embodied carbon building material and services, the energy efficiency of construction machines, as well as the renewable energy use are identified as three main pivotal opportunities to reduce the carbon emissions of the construction sector.