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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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A strawman proposal is given for a framework for presenting a common set of metrics for supercomputers, workstations, file servers, mass storage systems, and the networks that interconnect them. Production control and database systems are also included. Though other applications and third part software systems are not addressed, it is important to measure them as well.
A buffering heat exchanger/thermal energy storage (BHXTES) system was designed using a fast-response phase-change material/graphite foam (PCM/GF) medium for desalination and potentially other industrial applications. Unlike a store-now-and-use-later TES system, this study focused on developing a dynamically balanced, continuously used, system that optimized three functions. A lab-scale prototype was designed and fabricated with a PureTemp 151/GF storage medium. The experimental data showed excellent thermal performance repeatability indicating minimal effects of PCM expansion and contraction on the GF as well as negligible PCM redistribution effects. The experimental data also served as a validation of the numerical model of the BHXTES system, after which optimization of the BHXTES system was conducted through numerical simulations for both PureTemp 151/GF and solar salt/GF as the storage medium. The results show that, with a Therminol 55 heat transfer fluid, continuous operation of the system can be realized with a solar energy source through cycles of 8-h changing for desalination and energy storage with the supplied heat followed by 16-h discharging for desalination with the stored energy. As a result, the working fluid outlet temperatures are generally in the ranges of approximately 128–160 °C for a PureTemp 151/GF medium and 198–220 °C for a solar salt/GF medium.
The goal of the DOE OE ESS Safety Roadmap is to foster confidence in the safety and reliability of energy storage systems.
NEUP Final Technical Report outlines experimental and modeling efforts to characterize performance of thermal energy storage systems with molten salt as the phase change material.
This report investigates the technical performance of the 1 MW, 3.2 MWh advanced vanadium flow battery energy storage system (FBESS), consisting of two 0.5 MW, 1.6 MWh strings, based on a number of reference performance and use case tests. The FBESS is located on the utility 12 kV distribution system, between the Turner Substation and SEL’s manufacturing facility in Pullman, Washington. Reference performance tests (RPTs) were intended to assess the general technical capability of the FBESS (e.g., stored energy capacity, ramp rate performance, ability to track varying charge/discharge commands, direct current (DC) battery internal resistance). Use case tests were used to examine the performance of the FBESS while engaged in specific grid services (e.g., arbitrage, frequency regulation, balancing, volt ampere reactive (var) support, dynamic peak shaving). The project determined performance metrics that are important for understanding FBESS performance when subjected to field operation for achieving economic benefits from measurements and/or calculations. These metrics were: • RTE with and without rest, with and without auxiliary loads • Auxiliary power consumption • Reference signal tracking • Temperature excursions beyond normal operating range • Parasitic power loss unaccounted by auxiliary load during rest, and • State of charge (SOC) excursions beyond normal operating range. These RPT and use case performance metrics were analyzed using recorded test results. In addition, the results and lessons presented are also beneficial for any task or effort that needs technical assessment on similar and different types of FBESS, and BESS in general, based on technical specifications and/or field deployment results, since the assessment methodology remains the same.
The goal of the DOE OE ESS Safety Roadmap is to foster confidence in the safety and reliability of energy storage systems.
The contribution of intermittent (renewable) energy sources such as wind and solar continues to increase as renewables improve in both efficiency and price-point. However, the variability of renewables generates additional challenges for the electric grid in the form of rapidly varying electric loads. Proposed options for accommodating this load have included operating nuclear reactors in a load follow mode, or operating the reactor at or near steady state and bypassing steam directly to the condenser. Both of these strategies result in lost energy potential. In addition to lost energy potential, load follow operation can result in increased stress on the fuel and other mechanical components. A more attractive approach is to operate the reactor at or near steady state and bypass excess steam to a thermal energy storage system. The thermal energy can then be recovered, either for electric generation during periods of peak electric demand, or for use in ancillary applications such as desalination and hydrogen production. Sensible Heat Thermal Energy Storage is a mature technology currently used in solar energy systems. This research focuses on the design and coupling of such a system to Small Modular Reactors (SMRs), typical of Integral Pressurized Water Reactor (IPWR) designs currently under development. (authors)
This paper proposes a wireless power transfer (WPT) platform with integrated energy conversion that has the capability for 1) recharging the energy storage systems (ESSs) from the grid systems, including renewable energy sources such as wind, solar, etc., 2) off grid systems recharging the ESSs from dc grid systems, 3) grid recharging of electric vehicles (EVs), and 4) off grid recharging of EVs from ESSs. The unique aspect of the method is the use of multi-interface power electronic converter for the grid and ESSs and EVs that can support a range of applications with ac / dc and dc / dc energy conversion ability in a single converter system. The key enabling technology to achieve these functionalities is Oak Ridge Converter (ORC) with polyphase coupler coil system both developed at ORNL. This new technology enables higher power density WPT systems while allowing the coils to interface from ac grid at 60 Hz frequency or dc source directly merging with 85 kHz operating frequency of switching component. The experimental results of the proposed system are presented for 20 kW output power with the system overall efficiency around 95.4% from dc source and 93% overall efficiency from ac grid achieving 9-10% current total harmonic distortion (THD) and 0.98-0.99 power factor (PF).
Performance test data on high data rate storage system engineering models, and modifications to Nimbus ground stations
A description is given of a pulse-width-modulated buck-boost converter designed to interface a 500 Wh inertial energy storage system operating from 70 to 140 VDC to a constant bus of 150 VDC. Implementation of hysteresis feedback control provides excellent voltage regulation. The design is based on a 300-Wh, 94 percent Wh efficient prototype and is currently being optimized to yield 97 percent overall watt-hour efficiency.
A neural network controller has been developed to accommodate disturbances and nonlinearities and improve the robustness of a magnetically suspended flywheel energy storage system. The controller is trained using the back propagation-through-time technique incorporated with a time-averaging scheme. The resulting nonlinear neural network controller improves system performance by adapting flywheel stiffness and damping based on operating speed. In addition, a hybrid multi-layered neural network controller is developed off-line which is capable of improving system performance even further. All of the research presented in this paper was implemented via a magnetic bearing computer simulation. However, careful attention was paid to developing a practical methodology which will make future application to the actual bearing system fairly straightforward.
This is the modeling data (input/output files of TOUGHREACT 4.10) used to simulate the reactive transport processes of the Aquifer Thermal Energy Storage (ATES) operations at Stockton University, NJ. Readme.txt lists all the files. TOUGHREACT 4.10 requires to reproduce the modeling output. The modeling data in this submission is related to the Aquifer Injection for Energy Storage purposes outlined in "Reactive Transport Modeling of Aquifer Thermal Energy Storage System at Stockton, NJ During Seasonal Operations".
This paper is a discussion of the safety and cost of underground high-pressure air and gas storage systems based on recent experience with a high-pressure air system installed at Moffett Field, California. The system described used threaded and coupled oil well casings installed vertically to a depth of 1200 ft. Maximum pressure was 3000 psi and capacity was 500,000 lb of air. A failure mode analysis is presented, and it is shown that underground storage offers advantages in avoiding catastrophic consequences from pressure vessel failure. Certain problems such as corrosion, fatigue, and electrolysis are discussed in terms of the economic life of such vessels. A cost analysis shows that where favorable drilling conditions exist, the cost of underground high-pressure storage is approximately one-quarter that of equivalent aboveground storage.
Energy, environmental, and economic challenges are spurring more widespread consideration and use of energy storage systems (ESSs), which in turn are driving increased development of new ways to store energy electrochemically, mechanically, and thermally. These new methods necessitate an increased focus on ensuring that public health, safety, and welfare are not adversely affected—something that has been addressed for many years through codes, standards, and regulations (CSR5)1. CSRs provide requirements that establish a basis for determining if an ESS is safe, whether electrochemical, mechanical, or thermal and regardless of the range of ESS applications, energy capacities, physical sizes, location, or number installed at any given site. The key to achieving desired safety goals, as memorialized through CSRs, is through documenting and validating compliance with applicable CSRs. The process of documenting and validating compliance, which is a key component to the initial approval as well as continuing acceptance of an ESS installation, is generally called conformity assessment.
Utility-scale photovoltaics (PV) system market growth has been rapid for several years. Today, with the cost reductions of energy storage technologies, the application of combing PV and energy storage has become feasible and beneficial, especially for the areas that only have PV standalone systems and need to shift the peak load to meet the evening electricity demand. Overall, the utility-scale PV plus energy storage systems can provide dispatchable energy and reliable capacity. This study details cost factors, including labor costs, material costs, overhead, and permitting costs using a systemlevel bottom-up cost modeling approach. We use this model to benchmark PV plus storage installation system cost and identify cost difference for AC and DC coupled systems and duration variation. Finally, we assess the cost reduction opportunities of co-locating PV system with energy storage system in order to indicate the possible economic impacts of PV plus storage configuration and help future research and development (R&D) effects in the context of U.S. energy storage policymaking.
This report documents the test plans, including detailed duty cycles, used in evaluating the technical performance of five energy storage systems (ESSs) sponsored by the Washington State Clean Energy Fund (CEF). These ESSs were installed at three participating utilities’ (Avista, Snohomish Public Utility District or SnoPUD, and Puget Sound Energy or PSE) designated sites. Under each test plan, a number of baseline and use case tests are defined. This report documents the test plan for each utility, including duty cycles, data and performance reporting requirements. Baseline tests defined in this report mainly focus on determining an initial or reference performance for each ESS, which may be compared with the performance at any later time to assess the state of health of the ESS. Parameter values of a given ESS obtained from baseline tests are applied for different modeling purposes and use case tests. The stored energy capacity test is the first test conducted in the baseline test program, which generates data to calculate round trip efficiency (RTE). The response time and ramp rate tests provide the time required for an ESS to change from zero to full charging/discharging rate and hence the ramp rate, which is important in understanding ESS performance for applications calling for fast response. Internal resistance testing of ESS cells is also conducted in conjunction with the response time and ramp rate tests. Finally, the baseline tests include frequency regulation (FR) and peak shaving (PS) tests based on real-world duty cycles. Upon completion of the baseline tests, use case tests are conducted at each of the storage sites with duty cycles developed to meet the site-specific criteria and conditions. The use cases are grouped according to their intended target benefits within the electric infrastructure topology (e.g., transmission versus distribution). Although an ESS may be located on the low-voltage side of a substation that provides power to a distribution feeder, a use case that addresses bulk power services could still be provided and would be grouped under the transmission or bulk-power benefits. Use cases for ESS applications deep into the distribution circuit would be categorized under the distribution system cases.
In this paper, the system designs for hydrogen storage using chemical hydrogen materials in an 80 kWe fuel cell, light-duty vehicle are described. Ammonia borane and alane are used for these designs to represent the general classes of exothermic and endothermic materials. The designs are then compared to the USDRIVE/DOE developed set of system level targets for on-board storage. While most of the DOE targets are predicted to be achieved based on the modeling, the system gravimetric and volumetric densities were more challenging and became the focus of this work. The resulting system evaluation determined that the slurry is majority of the system mass. Only modest reductions in the system mass can be expected with improvements in the balance of plant components. Most of the gravimetric improvements will require developing materials with higher inherent storage capacity or by increasing the solids loading of the chemical hydrogen storage material in the slurry.
Oxidation-reduction couples in concentrated solutions separated by appropriate ion selective membranes were considered as an attractive approach to bulk electrical energy storage. A key problem is the development of the membrane. Several promising types of anionic membranes are discussed which were developed and evaluated for redox energy storage systems. The copolymers of ethyleneglycoldimethacrylate with either 2-vinylpyridine or vinylbenzl chloride gave stable resistance values compared to the copolymer of vinylbenzlchloride and divinylbenzene which served as the baseline membrane. A polyvinylchloride film aminated with tetraethylenepentamine had a low resistance but a high ion transfer rate. A slurry coated vinylpyridine had the lowest ion transfer rate. All these membranes functioned well in laboratory cells at ambient temperatures with the acidic chloride oxidant/reductant system, Fe 3, Fe 2/Ti 3, Ti 4.