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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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This technical report benchmarks current project financing costs for multiple renewable and conventional energy technologies, and looks out how these costs may change in the future. This report was performed in conjunction with NREL's Annual Technology Baseline.
The majority of modeled emissions scenarios that meet the climate change goals outlined in the 2015 Paris Agreement require not only significant reductions in anthropogenic carbon dioxide emissions, but also removal of carbon dioxide from the atmosphere ("negative emissions"). To date, research and development efforts have largely focused on land-based negative emissions technologies, such as bioenergy with carbon capture and storage. However, ocean-based technologies also have significant potential, and avoid competition for land use and fresh water with agriculture and human development. Marine carbon dioxide removal approaches include biological solutions that seek to increase carbon fixation through photosynthesis and chemical solutions that aim to increase the absorption of carbon dioxide in seawater. Most of these approaches have significant power requirements, especially when implemented at the scale necessary to meet negative-emissions goals. Marine renewable energy is uniquely poised to power marine carbon dioxide removal given its ability to provide carbon-free power at sea. In this work, the power requirements of marine carbon dioxide removal systems and the potential of marine renewable energy to power them are investigated, culminating in recommendations for future research and development to enable such developments.
Energy system projections from analytic models inform actions ranging from short-term and local decisions, such as technology and infrastructure deployment, to global and long-term negotiations and targets. Computational limits require the designers of these models to trade off between coverage and resolution. Some models, such as the Global Change Analysis Model (GCAM), represent all energy sources and uses but at a relatively coarse level of resolution. GCAM balances global supply and demand of all energy carriers by endogenously projecting prices for energy sources and costs of greenhouse gas mitigation while capturing interlinkages between the energy system, water, agriculture and land use, the economy, and the climate. This global model was used to frame the Long-Term Strategy released by the White House in 2021 and has been used to inform national and global economy-wide decarbonization discussions and strategy development for decades. Other models instead focus on a portion of the energy sector with greater detail and resolution. The Regional Energy Deployment System (ReEDS) electricity-sector model, for example, projects capacity expansion with an emphasis on integration of variable renewable energy into the grid of the future. The Transportation Energy and Mobility Pathway Options (TEMPO) transportation-sector model enables analysis of household choices in adoption, charging, and use of electric vehicles. The Scout buildings-sector model supports detailed consideration of the policies and markets that can accelerate the adoption of energy conservation measures in buildings. Such sector-specific models are instrumental in informing technology research, sectoral planning strategies, and sector-specific aspects of greenhouse gas (GHG) mitigation strategies in the United States. These global and sector-specific modeling approaches can complement each other. The global approach ensures consistent, endogenous energy pricing and resource allocation, which can substantially diverge from current conditions in transformative scenarios, while the sector-specific approach facilitates representation of granular details across spatial, temporal, technological, and market dimensions that enable exploration of particular interactions and trade-offs. This report presents the results of recent work to explore the differences and tradeoffs between these approaches by comparing GCAM with the sector-specific ReEDS, TEMPO, and Scout models. The report compares both model structures and results, and discusses their potential relevance and applications.
Redox flow batteries (RFBs), often categorized as aqueous and nonaqueous systems, represent a type of large-scale energy storage technology for renewable energy resources. Redox-active organic molecules have recently drawn extensive interests in RFBs as promising active materials due to their elemental abundance, structural diversity and high tunability of properties, but employing organic molecules in nonaqueous systems is far limited in terms of useable capacity and cycling stability. Here we introduce a class of azobenzene-based organic compounds with the azo group as redox-active center in the p-conjugated structure as new active materials to realize high-performance nonaqueous RFBs with long cycling life and high capacity. By screening suitable organic solvents with high solubility and conductivity, the azobenzene organic molecule was capable to achieve a stable long cycling with a low capacity decay of 0.014% per cycle and 0.16% per day over 1000 cycles. And the stable cycling of electrolytes under a high concentration of 1 M was also realized, delivering a high reversible capacity of ~46 Ah L -1 . The unique lithium-coupled redox chemistry accompanied with a voltage increase was observed and revealed by experimental characterization and theoretical simulation. With the reversible two-electron redox activity of azo group in p-conjugated structures, azobenzene as an azo-aromatic molecule represents a class of promising redox-active organics for potential grid-scale energy storage systems.
Our Renewable Energy Future delves into the clean energy technology evolution and where our energy system is going. While the book's foundation is technology innovation, it brings a unique perspective that technology alone is not what has brought about the explosive growth of renewable energy and offers fresh insights into how technology, economics, social dynamics, policy, and geopolitics are forces affecting our energy future. This book is a culmination of Dr Arent's lifelong passion for energy, sustainable development, and renewable energy technology. It covers the journey of evolving technology, economics, political economy and geopolitics of clean energy over the last 40 years and provides insights for the coming decades. From a technology perspective, the book traces the arc of recent innovations and synthesizes innovations across multiple interacting perspectives into a description of Our Renewable Energy Future.
Desalination technologies and industry have advanced significantly in the past two decades to meet the growing freshwater demands stimulated by the compounding issues of both water quality and quantity in many regions of the world. As desalination processes are energy demanding, there have been many efforts dedicated to improve energy-efficiency of the process units, enhance energy conservation and recovery, and increase renewable energy integration in desalination plants. This review article highlights recent key advances and discusses possible venues for further development in desalination energy portfolio to reduce specific energy consumption and, via integration with solar energy, to minimize the environmental footprint associated with freshwater production. First, an overview of current desalination technologies and their energy requirements are presented followed by a discussion on opportunities for improving energy efficiency and energy recovery in both membrane and thermal desalination technologies. Then, various combinations of renewable energy driven desalination plants are discussed with some recent highlights in solar energy driven membrane, thermal and hybrid desalination processes. Technological readiness levels for novel desalination processes, their perceived impact and expected near-future developments in renewable energy integrated desalination technologies are presented. Lastly, the potential for solar driven desalination as a cost-competitive freshwater supply alternative is discussed
In a webinar hosted by the U.S. Department of Energy's WINDExchange initiative, experts from the North Carolina Clean Energy Technology Center and the National Renewable Energy Laboratory introduce attendees to the key incentives supporting investment in wind energy deployment and manufacturing in the United States, as well as the role that the Inflation Reduction Act (IRA) plays in shaping those investments. Over the past few decades, incentives like the production tax credit and investment tax credit have supported the growth of wind energy deployment, while manufacturing-related incentives have helped scale up domestic manufacturing of wind energy components. With its passage in 2022, the IRA ushered in a new wave of investment in wind energy and other renewable technologies, as well as introducing new workforce requirements and equity provisions. This presentation explores the history and impact of major incentives, unpacks some of the complex provisions of the IRA, and highlights the ways federal incentives and policies will continue to shape the wind energy industry.
Addressing climate mitigation while meeting global electrification goals will require major transitions from fossil-fuel dependence to large-scale renewable energy deployment. However, renewables require significant land assets per unit energy and could come at high cost to ecosystems, creating potential conflicts between global climate mitigation and biodiversity conservation. Here, we explore the potential biodiversity implications of alternative future global electrification pathways as depicted under the Shared Socioeconomic Scenarios (SSPs), i.e., alternative trends in societal development. We examined the intersection of high-resolution estimates of global energy densities for ten renewable and conventional technologies with global richness data to estimate technology-specific biodiversity footprints (species per GWh), whereas a Cumulative Biodiversity Impact (CBI) score was used to assess land and biodiversity outcomes of alternative scenarios. Downscaled electricity generation scenarios (2020-2100) were also constrained by alternative land conservation and energy development policies. Unexpectedly, variation among SSPs did not exhibit a clear tradeoff between global climate mitigation and CBI. Rather, CBIs were an outcome of total infrastructure development to meet electricity demand (from population growth and GDP) and the total magnitude of renewable energy development and storage technologies. Renewables assembled along a spectrum from land sharing to sparing. At the land sharing end, biomass-powered electricity from dedicated crops contributed the most to biodiversity impacts due to low energy density, whereas land-sparing technologies (solar) caused more-intense land degradation, but in smaller areas. Our results suggest that local land conservation practices and strategies promoting energy diversification could have greater implications for future biodiversity conflicts than global socioeconomic drivers.
Renewable energy transition, once thought of as a singular, large-scale switch in industrial energy generating technologies from fossil fuels to renewables, have gained a broader set of requirements, including the need for justice and environmental protection. While discourse around policy and process has grown to consider these requirements, the focus of design of new renewable energy projects and technologies remains dominantly fixed on maximizing energy production, and renewables are falling short of meeting the requirements of just energy transitions. Meanwhile, in design studies, participatory and co-design approaches which explicitly consider justice in both process and outcomes have long been theorized and applied. However, applications of these approaches to renewable energy project design are under-theorized. In this paper, we explore the effectiveness of the adoption and adaptation of a co-design approach called Community-Driven Design (CDD) in enabling meaningful participation prior to technological maturity and bringing the attention of designers to a more diverse set of energy futures focused on justice and sustainability. Here, we do so by developing and testing the approach with community members in Sitka, AK, USA. We conclude that the approach has the potential to increase meaningful participation. Furthermore, we conclude that through diverse understandings of energy and the emergence of design narratives that engage with the complexity of vulnerability, accountability, and resilience, CDD led designers to consider justice, sustainability, and a diverse set of possible energy futures both within and beyond Sitka.
As variable renewable energy penetration increases beyond 80%, clean power systems will require long-duration energy storage or flexible, low-carbon generation. Here, we provide a detailed techno-economic evaluation and uncertainty analysis of applicable technologies and identify challenges and opportunities to support electric grid planning. We show that for a 120-h storage duration rating, hydrogen systems with geologic storage and natural gas with carbon capture are the least-cost low-carbon technologies for both current and future capital costs. These results are robust to uncertainty for the future capital cost scenario, but adiabatic compressed air and pumped thermal storage could be the least-cost technologies in the current capital cost scenario under uncertainty. Finally, we present a new storage system using heavy-duty vehicle fuel cells that could reduce the levelized cost of energy by 13%–20% compared with the best previously considered storage technology and, thus, could help enable very high (>80%) renewable energy grids.
Toyota has announced plans for commercial fuel cell vehicle deployment in 2015. To fully realize the benefits of fuel cell vehicles (zero emission with no performance loss in terms of vehicle range and capability), hydrogen produced efficiently from renewable sources is necessary. Most of the hydrogen fueling stations today utilize hydrogen reformed from natural gas (produced onsite or delivered). This enables more stations to be deployed cost-effectively within a network. Producing and using cost-effective renewable hydrogen in fuel cell vehicles will enable realization of the full potential. A viable option of green hydrogen that reliably delivers on the full suite of benefits for Toyota fuel cell vehicle drivers is needed. NREL is in a unique position to analyze and optimize renewable hydrogen production scenarios using the Energy Systems Integration Facility (ESIF), a facility that is specifically designed to evaluate renewable energy integration technologies. As the U.S. Department of Energy's (DOE) primary national laboratory for renewable energy and energy efficiency research and development, NREL has extensive knowledge of photovoltaic systems as well as alternative renewable technologies for efficient and reliable production of green hydrogen.
Polymer-electrolyte membrane (PEM) fuel-cells are one of the most promising energy conversion technologies for renewable clean energy applications. A major challenge preventing their widespread commercialization is achieving high performance with lowloadings of platinum group metal (PGM) catalysts. One of the factors driving performance limitations in the cell is the mass transport losses within the cathode catalyst layers due to sluggish oxygen-reduction reactions occurring at the platinum-ionomer interface, which is believed to be linked to reduced transport of ions and oxygen. A viable solution to reduce the transport resistances in the catalyst layers is to create new ionomers that can provide good ion and oxygen transport needed to accomplish high-performing fuel cell catalysts. Characterization of transport properties of ionomers for various molecular architectures is the key step, in the effort to create and identify the optimized polymer structure with improved transport. Using this approach, Tetramer Technologies and LBNL propose improved fuel-cell catalyst ionomers based on Tetramers proprietary polymer chemistry, as highlighted under subtopic 17a Innovative Approaches Toward Discovery and Development of Improved Ionomers for Polymer Electrolyte Membrane Fuel Cell Catalyst Layer.
Polymer-electrolyte membrane (PEM) fuel-cells are one of the most promising energy conversion technologies for renewable clean energy applications. A major challenge preventing the widespread use and commercialization of PEM fuel cells is achieving high performance with low-loadings of platinum group metal (PGM) catalysts. One of the factors driving performance limitations in the cell is the mass transport losses within the cathode catalyst layers (CCL) due to sluggish oxygen-reduction reactions occurring at the platinum-ionomer interface. Any resistance to transport of these ionic and gaseous species within the CCL results in mass-transport limitations and performance losses, especially at high current densities. It is known that mass-transport losses increase with reduced platinum loading, thereby creating a performance-cost tradeoff for fuel cells. A viable solution to reduce the transport resistances in the catalyst layers is to create new ionomers that can provide good ion and oxygen transport needed to accomplish high-performing fuel cell catalysts. Using this approach Tetramer Technologies and LBNL propose improved fuel-cell catalyst ionomers based on Tetramers proprietary polymer chemistry.
Globally, the iron and steel industry accounts for around a quarter of GHG emissions from the manufacturing sector , which is about 7% of the 33 gigatonnes (Gt) of global CO 2 emissions . Thus, globally, the steel industry is a 2-3 Gt CO 2 per year emissions challenge. The steel industry is important to the U.S. economy with output equal to $0.5 trillion and domestic production capacity is critical to national defense, infrastructure, energy production, and transportation. President Biden’s executive order on climate identifies actions and policies to put the Nation on a path to achieve net-zero carbon emissions, economy-wide, by no later than 2050. To achieve this, deep carbon reductions in the power, transportation, buildings and capital-intensive industrial manufacturing segments such as steel, cement and chemicals need to be addressed. In its recent “Accelerating Decarbonization of the U.S. Energy System” report , the National Academy of Sciences (NAS) stated that, “while technology exists to decarbonize all parts of the energy system, some sectors remain at precommercial or first-of-a-kind demonstration stages and require significant improvement in cost and performance to become commercially viable.” The NAS goes on to state that these hard to decarbonize sectors include “aviation, shipping, and industrial subsectors such as steel, cement, and chemicals manufacturing .” The Administration has proposed a timeline to decarbonize energy, transportation and then industry and manufacturing. From a life-cycle approach, decarbonizing steel and other large industrial inputs are necessary to decarbonize transformations in energy and transportation. DOE’s TRI-Lab Consortium’s Integrated Energy Systems (IES) program is a collaboration amongst DOE’s three applied energy laboratories: the National Energy Technology Laboratory; National Renewable Energy Laboratory and Idaho National Laboratory. The IES approach looks at more tightly integrating low-carbon nuclear energy, renewable electricity, energy storage, load/demand balancing, and biomass (including plastics and other wastes) with one or more industrial processes that utilize heat and/or power from these clean and waste energy sources to produce a low-carbon commodity-scale product.
This Final Technical Report summarizes the analytical, modeling, and engineering work performed to evaluate grid-forming (GFM) inverter capabilities within a large hybrid renewable energy facility. The project focused on assessing the ability of advanced inverter-based resources to provide essential reliability services through coordinated operation of grid-forming (GFM) and grid-following (GFL) technologies. During Budget Period 1, the project developed a comprehensive framework of GFM performance metrics, including angle support, voltage regulation, frequency response, damping behavior, and current-limiting performance. Extensive electromagnetic transient (EMT) studies and hardware-in-the-loop (HIL) testing were conducted to validate GFM behavior under a range of operating conditions, including weak-grid scenarios, voltage disturbances, and multi-resource interactions. The project also established validated modeling approaches, plant-level control integration strategies, commissioning frameworks, and high-speed measurement infrastructure to support future field demonstration. Although the project concluded prior to field demonstration, the results provide a utility-scale foundation for evaluating, modeling, and deploying grid-forming technologies. The methodologies and tools developed contribute to industry understanding of inverter-based resource behavior and support future power system reliability under increasing renewable penetration.
Biohydrogen is a clean and renewable source of energy. It can be produced by using technologies such as thermochemical, electrolysis, photoelectrochemical and biological, etc. Among these technologies, the biological method (dark fermentation) is considered more sustainable and ecofriendly. Dark fermentation involves anaerobic microbes which degrade carbohydrate rich substrate and produce hydrogen. Lignocellulosic biomass is an abundantly available raw material and can be utilized as an economic and renewable substrate for biohydrogen production. Although there are many hurdles, continuous advancements in lignocellulosic biomass pretreatment technology, microbial fermentation (mixed substrate and co-culture fermentation), the involvement of molecular biology techniques, and understanding of various factors (pH, T, addition of nanomaterials) effect on biohydrogen productivity and yield render this technology efficient and capable to meet future energy demands. Further integration of biohydrogen production technology with other products such as bio-alcohol, volatile fatty acids (VFAs), and methane have the potential to improve the efficiency and economics of the overall process. In this study, various methods used for lignocellulosic biomass pretreatment, technologies in trends to produce and improve biohydrogen production, a coproduction of other energy resources, and techno-economic analysis of biohydrogen production from lignocellulosic biomass are reviewed.
The need for smaller treatment facilities for more isolated or rural municipal entities and industrial water treatment facilities continues to grow. From environmental justice and energy needs in remote communities that have never been serviced by larger scale utilities to smaller onsite treatment requirements to meet discharge regulations, energy efficient treatment systems that can leverage renewable energy sources can be an important asset to owners. Climate change and population dynamics have changed the needs for distributed water treatment systems and the manner in which they function. New treatment technologies that can operate under dynamic conditions and leverage variable energy sources (e.g., renewable energy, RE) can provide substantial efficiencies and cost savings. The National Renewable Energy Laboratory (NREL) is embarking on research projects that will perform multi-scale studies to investigate treatment technologies on varying source water quality that can operate under unsteady state flow conditions (timing) in response to energy availability, supply, and demand. A pilot-scale system will be built to assess modularity and scaling of treatment system operating conditions and performance. Modeling will also be used to determine feasibility and integration into grid emulation platforms to understand the use and value of operation with RE. Optimization will be completed for the treatment and distribution systems to document strengths and weaknesses of using RE power sources. Results of this effort will advance dynamic water treatment understanding under variable conditions and integration of RE sources to power these systems. This will lead to further decarbonization of municipal and private treatment facilities while supporting a paradigm shift in water treatment process operation and system design to achieve net-zero goals and move toward energy-sensitive resilient water treatment systems.
While rapid deployment of variable renewable energy (VRE) technologies, namely wind and solar PV, is often projected in 2C pathways generated by integrated assessment models, there is a wide range in projected VRE deployment by mid-century. Such differences could be the result of differences in assumptions about future technology costs and/or differences in model approaches for capturing other aspects of technology competitiveness. Here we introduce a consistent competitiveness metric, profitability-adjusted levelized cost of electricity (or PLCOE), to an integrated assessment model (EPPA) to evaluate the representation of technology competition, including VRE, in low-emission scenarios. We show that representing the value of technology (alongside cost) may significantly impact VRE deployment relative to scenarios without such an adjustment. In addition, we show that varying VRE costs by about 35% in 2050 results in differences in VRE deployment that span much of the range in outcomes (over the same period) observed in likely 2C scenarios assessed by the IPCC, suggesting that both cost and value are key drivers of VRE deployment in such scenarios. Given the central role that VRE technologies play in the electricity mix across most scenarios, we also find that alternative cost assumptions for VRE technologies can lead to changes in electricity prices, the associated demand for electricity, and total final and primary energy consumption. However, the demand for fuels other than electricity is relatively insensitive to VRE assumptions in the 2C scenarios considered here.