A relative value framework: Why do different electricity system technologies have different economic value?
Not Available
Mowers, Matthew (ORCID:0000000198789588)↗
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Capacity value assessments of wind power
This article describes some of the recent research into the capacity value of wind power. With the worldwide increase in wind power during the past several years, there is increasing interest and significance regarding its capacity value because this has a direct influence on the amount of other (nonwind) capacity that is needed. We build on previous reviews from IEEE and IEA W ind T ask 25 a and examine recent work that evaluates the impact of multiple‐year data sets and the impact of interconnected systems on resource adequacy. We also provide examples that explore the use of alternative reliability metrics for wind capacity value calculations. We show how multiple‐year data sets significantly increase the robustness of results compared to single‐year assessments. Assumptions regarding the transmission interconnections play a significant role. To date, results regarding which reliability metric to use for probabilistic capacity valuation show little sensitivity to the metric. WIREs Energy Environ 2017, 6:e226. doi: 10.1002/wene.226 This article is categorized under: Wind Power > Economics and Policy Wind Power > Systems and Infrastructure Energy Infrastructure > Economics and Policy
Milligan, Michael↗
Evaluating the Value of High Spatial Resolution in National Capacity Expansion Models using ReEDS
Power sector capacity expansion models (CEMs) have a broad range of spatial resolutions. This paper uses the Regional Energy Deployment System (ReEDS) model, a long-term national scale electric sector CEM, to evaluate the value of high spatial resolution for CEMs. ReEDS models the United States with 134 load balancing areas (BAs) and captures the variability in existing generation parameters, future technology costs, performance, and resource availability using very high spatial resolution data, especially for wind and solar modeled at 356 resource regions. In this paper we perform planning studies at three different spatial resolutions--native resolution (134 BAs), state-level, and NERC region level--and evaluate how results change under different levels of spatial aggregation in terms of renewable capacity deployment and location, associated transmission builds, and system costs. The results are used to ascertain the value of high geographically resolved models in terms of their impact on relative competitiveness among renewable energy resources.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Substituent effects in a series of 1,7-C[subscript 60](R[subscript F])[subscript 2] compounds (R[subscript F] = CF[subscript 3], C[subscript 2]F[subscript 5], n-C[subscrip 3]F[subscript 7], i-C[subscript 3]F[subscript 7], n-C[subscript 4]F[subscript 9], s-C[subscript 4]F[subscript 9], n-C[subscript 8]F[subscript 17]): electron affinities, reduction potentials and E(LUMO) values are not always correlated
A series of seven structurally-similar compounds with different pairs of R{sub F} groups were prepared, characterized spectroscopically, and studied by electrochemical methods (cyclic and square-wave voltammetry), low-temperature anion photoelectron spectroscopy, and DFT calculations (five of the compounds are reported here for the first time). This is the first time that a set of seven R{sub F} groups have been compared with respect to their relative effects on E{sub 1/2}(0/-), electron affinity (EA), and the DFT-calculated LUMO energy. The compounds, 1,7-C{sub 60}(R{sub F}){sub 2} (R{sub F} = CF{sub 3}, C{sub 2}F{sub 5}, i-C{sub 3}F{sub 7}, n-C{sub 3}F{sub 7}, s-C{sub 4}F{sub 9}, n-C{sub 4}F{sub 9} and n-C{sub 8}F{sub 21}), were found to have statistically different electron affinities (EA), at the {+-}10 meV level of uncertainty, but virtually identical first reduction potentials, at the {+-}10 mV level of uncertainty. The lack of a correlation between EA and E{sub 1/2}(0/-), and between E(LUMO) and E{sub 1/2}(0/-), for such similar compounds is unprecedented and suggests that explanations for differences in figures of merit for materials and/or devices that are based on equating easily measurable E{sub 1/2}(0/-) values with EAs or E(LUMO) values should be viewed with caution. The solubilities of the seven compounds in toluene varied by nearly a factor of six, but in an unpredictable way, with the C{sub 2}F{sub 5} and s-C{sub 4}F{sub 9} compounds being the most soluble and the i-C{sub 3}F{sub 7} compound being the least soluble. The effects of the different R{sub F} groups on EAs, E(LUMO) values, and solubilities should help fluorine chemists choose the right R{sub F} group to design new materials with improved morphological, electronic, optical, and/or magnetic properties.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Contact value relations and density functional theory for the electrical double layer
The recently developed contact-corrected density functional theory is applied to an electric double layer containing a valence and size symmetric electrolyte. The restricted primitive model is used to describe the electrolyte, and a non-polarisable, smooth, planar, uniformly charged hard surface is used to model the electrode. Comparison with Monte Carlo simulation results for this system shows that the theory satisfies the first contact value relation in line with the premise of the approach. Additionally, the theory is found to satisfy the semi-empirical second contact value relation quite closely. This is a welcome result, since no reference is made to this second relation nor is the relation used in the theoretical development. The second contact relation is closely related to the anomalous positive temperature derivative of the double layer capacitance at low temperature, low ion concentration, and low electrode charge, and indeed, the contact-corrected density functional theory predicts this effect.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
A dual model HU conversion from MRI intensity values within and outside of bone segment for MRI-based radiotherapy treatment planning of prostate cancer
Purpose: The lack of electron density information in magnetic resonance images (MRI) poses a major challenge for MRI-based radiotherapy treatment planning (RTP). In this study the authors convert MRI intensity values into Hounsfield units (HUs) in the male pelvis and thus enable accurate MRI-based RTP for prostate cancer patients with varying tissue anatomy and body fat contents. Methods: T{sub 1}/T{sub 2}*-weighted MRI intensity values and standard computed tomography (CT) image HUs in the male pelvis were analyzed using image data of 10 prostate cancer patients. The collected data were utilized to generate a dual model HU conversion technique from MRI intensity values of the single image set separately within and outside of contoured pelvic bones. Within the bone segment local MRI intensity values were converted to HUs by applying a second-order polynomial model. This model was tuned for each patient by two patient-specific adjustments: MR signal normalization to correct shifts in absolute intensity level and application of a cutoff value to accurately represent low density bony tissue HUs. For soft tissues, such as fat and muscle, located outside of the bone contours, a threshold-based segmentation method without requirements for any patient-specific adjustments was introduced to convert MRI intensity values into HUs. The dual model HU conversion technique was implemented by constructing pseudo-CT images for 10 other prostate cancer patients. The feasibility of these images for RTP was evaluated by comparing HUs in the generated pseudo-CT images with those in standard CT images, and by determining deviations in MRI-based dose distributions compared to those in CT images with 7-field intensity modulated radiation therapy (IMRT) with the anisotropic analytical algorithm and 360° volumetric-modulated arc therapy (VMAT) with the Voxel Monte Carlo algorithm. Results: The average HU differences between the constructed pseudo-CT images and standard CT images of each test patient ranged from −2 to 5 HUs and from 22 to 78 HUs in soft and bony tissues, respectively. The average local absolute value differences were 11 HUs in soft tissues and 99 HUs in bones. The planning target volume doses (volumes 95%, 50%, 5%) in the pseudo-CT images were within 0.8% compared to those in CT images in all of the 20 treatment plans. The average deviation was 0.3%. With all the test patients over 94% (IMRT) and 92% (VMAT) of dose points within body (lower than 10% of maximum dose suppressed) passed the 1 mm and 1% 2D gamma index criterion. The statistical tests (t- and F-tests) showed significantly improved (p ≤ 0.05) HU and dose calculation accuracies with the soft tissue conversion method instead of homogeneous representation of these tissues in MRI-based RTP images. Conclusions: This study indicates that it is possible to construct high quality pseudo-CT images by converting the intensity values of a single MRI series into HUs in the male pelvis, and to use these images for accurate MRI-based prostate RTP dose calculations.
62 RADIOLOGY AND NUCLEAR MEDICINE↗
Data Challenges in Estimating the Capacity Value of Solar Photovoltaics
We examine the robustness of solar capacity-value estimates to three important data issues. The first is the sensitivity to using hourly averaged as opposed to subhourly solar-insolation data. The second is the sensitivity to errors in recording and interpreting load data. The third is the sensitivity to using modeled as opposed to measured solar-insolation data. We demonstrate that capacity-value estimates of solar are sensitive to all three of these factors, with potentially large errors in the capacity-value estimate in a particular year. If multiple years of data are available, the biases introduced by using hourly averaged solar-insolation can be smoothed out. Multiple years of data will not necessarily address the other data-related issues that we examine. Our analysis calls into question the accuracy of a number of solar capacity-value estimates relying exclusively on modeled solar-insolation data that are reported in the literature (including our own previous works). Our analysis also suggests that multiple years' historical data should be used for remunerating solar generators for their capacity value in organized wholesale electricity markets.
14 SOLAR ENERGY↗
Key-value store with internal key-value storage interface
A key-value store is provided having one or more key-value storage interfaces. A key-value store on at least one compute node comprises a memory for storing a plurality of key-value pairs; and an abstract storage interface comprising a software interface module that communicates with at least one persistent storage device providing a key-value interface for persistent storage of one or more of the plurality of key-value pairs, wherein the software interface module provides the one or more key-value pairs to the at least one persistent storage device in a key-value format. The abstract storage interface optionally processes one or more batch operations on the plurality of key-value pairs. A distributed embodiment for a partitioned key-value store is also provided.
97 MATHEMATICS AND COMPUTING↗
Potential Economic Values of Low-Vapor-Pressure Gasoline-Range Bio-Blendstocks: Property Estimation, and Blending Optimization
Adding non-traditional blendstocks derived from biomass into gasoline has gained renewed interest since it will reduce greenhouse gas emissions and potentially enhance fuel properties and boost engine efficiencies. A competitive bio-blendstock candidate should have either lower prices or superior properties or both relative to conventional gasoline blending components. Gasoline is a mixture of hundreds compounds specified by properties rather than compositions. The addition of bio-blendstocks, most likely oxygenates, will modify the property mixing rules due to the non-ideal interactions between polar and nonpolar components. This paper presents an equation-of-state-based model for predicting Reid vapor pressure, reduced order non-linear property blending models for computing key properties of final gasoline products, and a blending optimization approach to identify key economic drivers. This paper also evaluates the economic values of bio-blendstocks to petroleum refiners using those models. In additional to ethanol, six low-vapor-pressure bio-blendstock candidates were evaluated: i-propanol, n-propanol, i-butanol, diisobutylene, cyclopentanone, and a mixture of furans. Reid vapor pressure, distillation temperatures, and octane numbers were identified as the key economic drivers of adding bio-blendstock. The economic values of those bio-blendstocks range from 2.22 to 4.00 US dollar per gasoline gallon equivalent in 2013 to 2017 5-year averaged price basis. The bio-blendstocks with higher octane numbers may have higher economic values. The uncertainties in property predictions may lead to roughly 15% deviation in the economic value evaluation.
Jiang, Yuan↗
Assigning value to energy storage systems at multiple points in an electrical grid
The ability to define the potential value that energy storage systems (ESS) could generate through various applications in electric power systems, and an understanding of how these values change due to variations in locations, ESS performance and parameters, market structure, utility structures, and valuation methodologies is highly important in advancing ESS deployment. This paper presents the outcome of an effort to assign benefits values, or more precisely ranges of values, to major ESS applications, and summarize and evaluate the capabilities of several available tools currently used to estimate value for specific ESS deployments.
energy storage valuation, balducci, energy storage↗
Precise $\textit{Q}$-value measurements of 112,113 Ag and 115 Cd with the Canadian Penning trap for evaluation of potential ultralow $\textit{Q}$-value $\textit{β}$ decays
Background: An ultralow $\textit{Q}$-value $\textit{β}$ decay can occur from a parent nuclide to an excited nuclear state in the daughter such that $Q_{\text{UL}}$ 1 keV. These decay processes are of interest for nuclear $\textit{β}$-decay theory and as potential candidates in neutrino mass determination experiments. To date, only one ultralow $\textit{Q}$-value $\textit{β}$ decay has been observed—that of 115 In with $Q_β$ = 147(10) eV. A number of other potential candidates exist, but improved mass measurements are necessary to determine if these decay channels are energetically allowed and, in fact, ultralow. Purpose: To perform precise $\textit{β}$-decay $\textit{Q}$-value measurements of 112,113 Ag and 115 Cd and to use them in combination with nuclear energy level data for the daughter isotopes 112,113 Cd and 115 In to determine if the potential ultralow $\textit{Q}$-value $\textit{β}$-decay branches of 112,113 Ag and 115 Cd are energetically allowed and 1 keV. Method: The Canadian Penning Trap at Argonne National Laboratory was used to measure the cyclotron frequency ratios of singly charged 112,113 Ag and 115 Cd ions with respect to their daughters 112,113 Cd and 115 In. From these measurements, the ground-state to ground-state $\textit{β}$-decay $\textit{Q}$ values were obtained. Results: The 112 Ag → 112 Cd, 113 Ag → 113 Cd, and 115 Cd → 115 In $\textit{β}$-decay $\textit{Q}$ values were measured to be $Q_β$( 112 Ag) = 3990.16(22) keV, $Q_β$( 113 Ag) = 2085.7(4.6) keV, and $Q_β$( 115 Cd) = 1451.36(34) keV. These results were compared to energies of excited states in 112 Cd at 3997.75(14) keV, 113 Cd at 2015.6(2.5) and 2080(10) keV, and 115 In at 1448.787(9) keV, resulting in precise $Q_{\text{UL}}$ values for the potential decay channels of –7.59(26) keV, 6(11) keV, and 2.57(34) keV, respectively. Conclusion: The potential ultralow $\textit{Q}$-value decays of 112 Ag and 115 Cd have been ruled out. 113 Ag is still a possible candidate until a more precise measurement of the 2080(10) keV, 1/2+ state of 113 Cd is available. In the course of this work we have found the ground state mass of 113 Ag reported in the 2020 Atomic Mass Evaluation [Wang et al., Chin. Phys. C 45, 030003 (2021)] to be lower than our measurement by 69(17) keV (a 4σ discrepancy).
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Defining Threshold Values of Encapsulant and Backsheet Adhesion for PV Module Reliability
The width-tapered cantilever beam method is used to quantify the debond energy (adhesion) of encapsulant and backsheet structures of 32 modules collected from the field. The collected population of modules contains both those that have remained intact and those with instances of either or both encapsulant and backsheet delamination. From this survey, initial threshold values (an adhesion value above which a module should remain intact throughout its lifetime) for encapsulant and backsheet interfaces are proposed. For encapsulants this value is ~ 160J/m 2 and for backsheets ~ 10J/m 2 . Here, it is expected that these values will continue to be refined and evolve as the width-tapered cantilever beam method gets adopted by the PV industry, and that they may aid in the future improvement of accelerated lifetime tests and the development of new, low-cost materials.
14 SOLAR ENERGY↗
Baseline and Target Values for PV Forecasts: Toward Improved Solar Power Forecasting
Accurate solar power forecasting allows utilities to get the most out of the solar resources on their systems. To truly measure the improvements that any new solar forecasting methods can provide, it is important to first develop (or determine) baseline and target solar forecasting at different spatial and temporal scales. This paper aims to develop baseline and target values for solar forecasting metrics. These were informed by close collaboration with utility and independent system operator partners. The baseline values are established based on state-of-the-art numerical weather prediction models and persistence models. The target values are determined based on the reduction in the amount of reserves that must be held to accommodate the uncertainty of solar power output.
14 SOLAR ENERGY↗
Stationary table CT dosimetry and anomalous scanner-reported values of CTDI{sub vol}
Purpose: Anomalous, scanner-reported values of CTDI{sub vol} for stationary phantom/table protocols (having elevated values of CTDI{sub vol} over 300% higher than the actual dose to the phantom) have been observed; which are well-beyond the typical accuracy expected of CTDI{sub vol} as a phantom dose. Recognition of these outliers as “bad data” is important to users of CT dose index tracking systems (e.g., ACR DIR), and a method for recognition and correction is provided. Methods: Rigorous methods and equations are presented which describe the dose distributions for stationary-table CT. A comparison with formulae for scanner-reported values of CTDI{sub vol} clearly identifies the source of these anomalies. Results: For the stationary table, use of the CTDI{sub 100} formula (applicable to a moving phantom only) overestimates the dose due to extra scatter and also includes an overbeaming correction, both of which are nonexistent when the phantom (or patient) is held stationary. The reported DLP remains robust for the stationary phantom. Conclusions: The CTDI-paradigm does not apply in the case of a stationary phantom and simpler nonintegral equations suffice. A method of correction of the currently reported CTDI{sub vol} using the approach-to-equilibrium formula H(a) and an overbeaming correction factor serves to scale the reported CTDI{sub vol} values to more accurate levels for stationary-table CT, as well as serving as an indicator in the detection of “bad data.”.
62 RADIOLOGY AND NUCLEAR MEDICINE↗
Spectral dilation of L(B,H)-valued measures and its application to stationary dilation for Banach space valued processes
Let B be a Banach space and H and K two Hilbert spaces. The spectral dilation of L(B,H)-valued measures is studied and it is shown that the recent results of Makagon and Salehi (1986) and Rosenberg (1982) on the dilation of L(K,H)-valued measures can be extended to hold for the general Banach space setting of L(B,H)-valued measures. These L(B,H)-valued measures are closely connected to the Banach space valued processes. This connection is recalled and as application of spectral dilation of L(B,H)-valued measures the well known stationary dilation results for scalar valued processes is extended to the case of Banach space valued processes.
Miamee, A. G.↗
Spectral dilation of L(B,H)-valued measures and its application to stationary dilation for Banach space valued processes
Let B be a Banach space and H and K to Hilbert spaces. The spectral dilation of L(B,H)-valued measures is studied and it is shown that the recent results of Makagon and Salehi (1986) and Rosenberg (1982) on the dilation of L(K,H)-valued measures can be extended to hold for the general Banach space setting of L(B,H)-valued measures. These L(B,H)-valued measures are closely connected to the Banach space valued processes. This connection is recalled and as application of spectral dilation of L(B,H)-valued measures the well known stationary dilation results for scalar valued processes is extended to the case of Banach space valued processes.
Miamee, A. G.↗
Estimating the Capacity Value of Concentrating Solar Power Plants With Thermal Energy Storage: A Case Study of the Southwestern United States
Abstract not provided
14 SOLAR ENERGY↗
Impacts of valuing resilience on cost-optimal PV and storage systems for commercial buildings
Not Available
Laws, Nicholas D.↗