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DOE OSTI2018

U.S. Solar Photovoltaic System Cost Benchmark: Q1 2018

NREL has been modeling U.S. photovoltaic (PV) system costs since 2009. This report benchmarks costs of U.S. solar PV for residential, commercial, and utility-scale systems built in the first quarter of 2018 (Q1 2018). Our methodology includes bottom-up accounting for all system and project-development costs incurred when installing residential, commercial, and utility-scale systems, and it models the capital costs for such systems.

14 SOLAR ENERGY↗

DOE OSTI2018

2018 U.S. Utility-Scale Photovoltaics-Plus-Energy Storage System Costs Benchmark

Market growth for utility-scale photovoltaic (PV) systems has been rapid for several years. Today, with the cost reductions of energy storage technologies, the combining PV and energy storage has become feasible and beneficial, especially for the areas that have only PV standalone systems and need to shift the peak load to meet electricity demand in the evening. Overall, 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 system-level bottom-up cost modeling approach. We use this model to benchmark PV-plus-storage installation system cost and identify the cost difference for AC- and DC-coupled systems and duration variation. Finally, we assess the cost reduction opportunities of colocating PV systems with energy storage systems in order to indicate the possible economic impacts of the PV-plus-storage configuration and help future research and development (R&D) effects in the context of U.S. energy storage policymaking.

14 SOLAR ENERGY↗

DOE OSTI2018

Integrated Multi Scale Data Analytics and Machine Learning for the Grid; Benchmarking Algorithms and Data Quality Analysis

Machine Learning and Data Analytics are terms which are utilized now ubiquitously throughout grid analytics forums, as a potential solution to the growing big data challenges for the distribution grid. As sensors become inexpensive and common, and communication networks grow, the analytics themselves must adapt and enable consumers and providers to visualize and utilize the data provided effectively. Machine learning is one of the techniques proposed in order to manage this data deluge. This report is a subset of the work in this activity, funded through the DOE Grid Modernization Initiative, to summarize the benchmarking and review of data quality impact on the algorithm sets being developed within each use case area.

42 ENGINEERING↗

DOE OSTI2019

Crystalline Silicon Photovoltaic Module Manufacturing Costs and Sustainable Pricing: 1H 2018 Benchmark and Cost Reduction Road Map

In this paper we provide an overview of the accounting methods and most recent input data used within NREL's bottom-up crystalline silicon (c-Si) solar photovoltaic (PV) module supply chain cost models. The costs accounting framework that is detailed in this paper provides a methodology to prepare bottom-up c-Si PV supply chain cost models in accordance with the U.S. Generally Accepted Accounting Principles (GAAP) and the International Financial Reporting Standards (IFRS). For the polysilicon, ingot, wafer, cell conversion, and module assembly steps of the c-Si supply chain, we outline what is relevant for calculations of the costs of goods sold (consisting of the materials, labor, electricity, maintenance, and depreciation of capital equipment); as well as the additional operating expenses of research and development (R&D); and sales, general, and business administration (S, G, &A). This 2017 benchmark analysis is applied to current state-of-the-art manufacturing sites located within the United States, China, Taiwan, South Korea, Malaysia, the Philippines, and Germany. Primarily due to country-dependent labor and electricity rates, tax rates, and cost-of-capital considerations, we calculate differences in minimum sustainable pricing for all of these countries. In this paper we also include technical descriptions and bottom-up cost model results for several emerging c-Si technologies including larger Czochralski (Cz) ingots, kerfless wafers, reduced silicon utilization by thinner wafers and advanced diamond wire wafering, new encapsulants and backsheets, shingled cells, and the cell architectures passivated emitter and rear cells (PERC), bifacial passivated emitter and rear totally diffused (PERT) cells, bifacial heterojunction intrinsic thin layer (HIT) cells, and interdigitated all back-contact cells (IBC).

14 SOLAR ENERGY↗

DOE OSTI2019

LANL ARM Benchmarking Efforts

This report gives an overview of LANL ARM benchmarking efforts, mini-app performance characteristics, ASC/IC app performance resutls, and ARM future technologies.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2019

Benchmarking Wind Power Operating Costs in the United States: Results from a Survey of Wind Industry Experts

This paper draws on a survey of wind industry professionals to clarify trends in the operational expenditures (OpEx) of U.S. land-based wind power plants. The paper also highlights key drivers of those trends. We find that average all-in lifetime OpEx has declined from approximately $\$$80/kW-yr ($\$$35/MWh) for projects built in the late 1990s to a level that is approaching $\$$40/kW-yr ($\$$11/MWh) for projects under construction in 2018. Turbine operations and maintenance (O&M) costs—inclusive of scheduled and unscheduled maintenance—represent the single largest component of overall OpEx and the primary source of cost reductions over the last decade. We observe wide ranges of OpEx over time; for example, survey respondents cite a range in average expected costs for projects commissioned between 2015 and 2018 from $\$$33/kW-yr to $\$$59/kW-yr. Notably, these broad ranges include high levels of variability in both turbine O&M costs and non-turbine OpEx. Potential technical and strategic drivers of this variability are highlighted. We also use historical OpEx learning rates, showing a 9% OpEx reduction for each doubling of global installed wind capacity, to project a further $\$$5–$\$$8/kW-yr (12%–18%) OpEx reduction from 2018 to 2040. When compared with the broader literature, these findings suggest that continued OpEx reductions may contribute 10% or more of the expected reductions in land-based wind’s levelized cost of energy. Moreover, these estimates may understate the importance of OpEx owing to the multiplicative effects through which operational advancements influence not only O&M costs but also component reliability, performance, and plant-level availability—thereby affecting levelized costs though OpEx reduction and by enhancing annual energy production and plant lifetimes. Given the limited quantity and comparability of previously available OpEx data, the data and trends reported here may usefully inform OpEx assumptions used by electric system planners, analysts, modelers, and research and development managers. The results may also provide useful benchmarks to the wind industry, helping developers and asset owners compare their OpEx expectations with historical experience and other industry projections.

17 WIND ENERGY↗

DOE OSTI2019

Big Ten MCNP6 Unstructured Mesh Benchmark

The purpose of this report is to document a benchmarking effort for the MCNP6 Unstructured Mesh (UM) geometry description method applied to a large and fairly complex critical assembly, Big Ten. A secondary goal of this effort is to provide a set of best practices for modeling a critical assembly with the MCNP UM method. Specification of geometry using UM requires creating a mesh from a solid geometry model and there are some important considerations when using this method for criticality problems. These considerations will be discussed along with suggested practices for correctly modeling these types of problems.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2019

Benchmarking Algorithm for Radio Nuclide Identification (BARNI) Literature Review

This is a literature review of published radioisotope identification (ID) methods, and an attempt at systematic organization of the approaches for solving this problem. In addition, there is an overview of the related open and closed source software, and patents related to radioisotope identification. This document is also part of the development plan for BARNI (Benchmarking Algorithm for RadioNuclide Identification) software, since it is meant to be a comparison tool, a summary of radiation ID performance evaluations is also included.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2019

LANL ARM Benchmarking Efforts

Overview of LANL ARM benchmarking efforts; ASC application performance on current ARM systems; ARM future technologies investigations; and external collaborations.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2019

Laghos summary for CTS2 benchmark

Laghos (LAGrangian High-Order Solver) is a miniapp that solves the time-dependent Euler equations of compressible gas dynamics in a moving Lagrangian frame using unstructured highorder finite element spatial discretization and explicit high-order time-stepping. Results and benchmark tarball are for the cts2 version from the CEED/Laghos repository.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2019

Development of Reactor Physics Benchmark Evaluations for Power Burst Facility Experiments

The PBF is an open vessel with a closed loop water cooling system that can handle up to 28MW of heat generation during steady state operations. This project details the facility characteristics relevant to performing simulation benchmarks for the intent of inclusion in the International Reactor Physics Experiment Evaluation Project (IRPhEP).

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2019

Benchmarking Anticipated Wind Project Lifetimes: Results from a Survey of U.S. Wind Industry Professionals

This paper draws on a survey of wind industry professionals to clarify trends in the expected useful life of land-based wind power plants in the United States. The expected useful life of a project affects expectations about its profitability, the timing of possible decommissioning or repowering, and its levelized costs. We find that most wind project developers, sponsors and long-term owners have increased project-life assumptions over time, from a typical term of ~20 years in the early 2000s to ~25 years by the mid-2010s and ~30 years more recently. Current assumptions range from 25 to 40 years, with an average of 29.6 years. The estimated average levelized cost of energy (LCOE) for new wind projects built in 2018 is $\$ $40.4/MWh (real 2018$\$ $), assuming a 20-year project life. With a 25-year useful life and no change in assumed operations and maintenance (O&M) expenditures or wind plant performance over time, LCOE declines by 10%, to $\$ $36.2/MWh, because capital costs are recovered over five additional years of production. At the now-common 30-year assumed life, levelized costs decrease another 7%, to $\$ $33.5/MWh (under the same unaltered assumptions about O&M and performance). Even longer assumed lifetimes lead to further (but diminishing) LCOE reductions—e.g., to $\$ $31.7/MWh and $\$ $30.3/MWh for 35- and 40-year lives, respectively. The data and trends presented here may inform assumptions used by electric system planners, modelers and analysts. The results may also provide useful benchmarks to the wind industry, helping developers and assets owners to compare their expectations with those of their peers.

17 WIND ENERGY↗

DOE OSTI2019

Nuclear Data – Benchmarking 19 F(α,n) Yield Data for Nuclear Safeguards

Fluorine compounds of U and Pu are ubiquitous in the nuclear fuel cycle, so F(α,n) neutrons are an important signature and quantitative source term that needs to be understood for physics-based interpretation of nondestructive assay measurements. Historically there have been large differences in the basic nuclear data for this reaction reported by various groups. UF 6 is the most prominent material in the nuclear fuel cycle, with the potential for short-term production into weaponizable form. Verification of bulk quantities, natural feed, depleted tails, and especially low enriched product in cylinders is particularly important. The principal physical measurement is neutron counting. For enriched material, the 19 F(α,n) reaction, driven by 234U, is the dominant source of neutrons. Basic nuclear data, cross sections, needed to calculate the yield, as well as information on the source spectrum for sensitivity studies are sparse and highly discrepant. This limits defensible physics-based performance evaluations. The same applies to holdup and criticality studies in which hydrated uranyl fluoride is the material of interest which accumulates in enrichment facilities. In the future we anticipate that the physics community will have made improved accelerator-based measurements and undertaken a more thorough evaluation and adjustment of all relevant available data. But in the short term, this does not help the safeguards community face the pressing real-world nondestructive assay requirements. To address this need, we have performed quality neutron measurements on UF6 materials using well-known material and high-capability neutron counters. A robust determination of the n/s/g of 234 U in UF 6 was generated along with a scientifically defensible uncertainty analysis. The weighted average value of the neutron yield is 509 n/s/g 234 U with a random uncertainty of approximately 1%. Dominant sources of systematic uncertainty are in the efficiency determination where we incur approximately 1.1% relative standard deviation associated with the 252 Cf reference source and about 0.9% uncertainty coming from the uncertainty in the F(α,n) spectrum. The stated uncertainties are an order of magnitude better than current data based on accelerator data reported in the literature. Aside from being of immediate and direct use by the safeguards community, this result will serve as an enduring integral benchmark for subsequent data evaluations that will need to match it in order to be credible. In addition to yield normalization, safeguards users of F(α,n) data also need guidance of the neutron emission spectrum. We have generated a neutron emission using a modified version of the well-known SOURCES 4C code, updated with new alpha stopping power coefficients, and a blended microscopic cross section data set. The yield and spectra are available in a form that MCNP users can readily use.

36 MATERIALS SCIENCE↗

DOE OSTI2019

MSRE TRANSFORM Model for Thermal-Hydraulic Benchmarking (Status Report)

Over the last several years, there has been renewed interest in the development of molten salt reactor concepts for the next generation of nuclear power plants. The modeling tools used to design these reactors must be validated in order to accurately predict the thermal hydraulic behavior expected during operation. The majority of the practical experience with molten salt reactors comes from the Molten Salt Reactor Experiment (MSRE) that operated at Oak Ridge National Laboratory (ORNL) from 1964 until 1969. The work discussed in this paper uses the design information and experimental data from that period to create and validate a detailed model of the MSRE. Once completed, this model’s performance will be compared to other system analysis codes for thermal hydraulic benchmarking, and their ability to predict the thermal hydraulic performance of molten salt reactor systems will also be compared.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

DOE OSTI2019

Status Report on the MSRE Transform Model for Thermal-Hydraulic Benchmarking

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2019

Documentation Package Supporting Fabrication of Doped UO 2 Samples for MiniFuel Irradiation and Fission Gas Release Benchmarking

The Oak Ridge National Laboratory (ORNL) is looking into the fabrication of high performance UO 2 fuel candidates via the addition of dopants to the UO 2 . The addition of dopants is proposed to cause enlarged grains that will slow down fission gas release from the irradiated fuel pellet candidates. The Cr-doped UO 2 pellets were fabricated from a microspherical feedstock, and enlarged grains were observed during the microstructural characterization. Irradiation under the Miniature Fuel program in the High Flux Isotope Reactor at ORNL will enable the study of irradiation response of such potential fuel candidates and will allow fission gas release benchmarking for these fuel candidates.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2020

Benchmarking Utility-Scale PV Operational Expenses and Project Lifetimes: Results from a Survey of U.S. Solar Industry Professionals

This paper draws on a survey of solar industry professionals and other sources to clarify trends in the expected useful life and operational expenditure (OpEx) of utility-scale photovoltaic (PV) plants in the United States. Solar project developers, sponsors, long-term owners, and consultants have increased project-life assumptions over time, from an average of ~21.5 years in 2007 to ~32.5 years in 2019. Current assumptions range from 25 years to more than 35 years depending on the organization; 17 out of 19 organizations surveyed or reviewed use 30 years or more. Levelized, lifetime OpEx estimates have declined from an average of ~$\$$35/kW DC -yr for projects built in 2007 to an average of ~$\$$17/kW DC -yr in 2019. Across 13 sources, the range in average lifetime OpEx for projects built in 2019 is broad, from $\$$13 to $\$$25/kW DC -yr. Operations and maintenance (O&M) costs—one component of OpEx—have declined precipitously in recent years, to $\$$5-8/kW DC -yr in many cases. Property taxes and land lease costs are highly variable across sites, but on average are—together—of similar magnitude. Other OpEx line items include security, insurance, and asset management. Given 2007-2009 values for not only project life and OpEx but also other drivers of the levelized cost of energy (LCOE, excluding the investment tax credit), the LCOE for utility-scale PV projects built from 2007 through 2009 averaged $\$$305 /MWh. Using 2019 values for all parameters yields an average LCOE of $\$$51 /MWh. The decline in LCOE from $\$$305 /MWh to $\$$51 /MWh was predominantly caused by reductions in up-front expenditures (and, to a much lesser extent, by changes in capacity factors, financing costs, and tax rates), but 9% ($\$$22 /MWh) of the overall decline is due to improvements in project life and OpEx. Project life extensions and OpEx reductions have had similarly sized impacts on LCOE over this period, at $\$$11 /MWh each. Had project life and OpEx not improved over the last decade, LCOE in 2019 would have instead been $\$$73 /MWh—43% higher. Given the limited quantity and comparability of previously available data on these cost drivers, the data and trends presented here may inform assumptions used by electric system planners, modelers, and analysts. The results may also provide useful benchmarks to the solar industry, helping developers and assets owners compare their expectations for project life and OpEx with those of their peers.

14 SOLAR ENERGY↗

DOE OSTI2020

Benchmark Solutions for Radiation Transport in Stochastic Media with Inhomogeneous Material Statistics

Accurately solving implicit Monte Carlo (IMC) thermal photon transport problems with mixed material cells is important in realistic applications. The production IMC package at LLNL treats mixed material cells arising from ALE remap and hydrodynamics using the same approximate model. The new Imp IMC thermal photon transport package currently under development has both a material interface reconstruction (MIR) algorithm and a Levermore-Pomraning (LP) stochastic medium algorithm for treating mixed material cells. Existing stochastic medium algorithms for treating mixed material cells in IMC lack a complete theoretical basis. The IMC LP algorithm implementation has been demonstrated to reproduce published deterministic LP solutions for the particular case of spatially homogeneous material statistics. Realistic simulations will include spatially inhomogeneous material statistics (material mean chord lengths). In a previous investigation, the LP-model for transport in binary stochastic media in rod geometry was generalized to accommodate spatially varying material chord lengths, i.e., the mixing statistics were allowed to be nonhomogeneous. Analytical solutions were obtained and used to produce a verifi cation suite for the Imp IMC Levermore-Pomraning implementation for different spatial variations of the chord lengths. However, the accuracy of the LP model when the mixing statistics are nonhomogeneous has not been assessed and leaves open the question of whether local accuracy is improved or further degraded when chord lengths are not uniform. This shortcoming is rectifi ed here by developing benchmark analytic solutions for transport in binary Markovian stochastic mixtures in rod geometry with nonhomogeneous mixing statistics, using spatially varying chord lengths considered in the previous investigation based on the LP model. Methods for sampling a nonhomogeneous Poisson process (NHPP) are first described and used to construct individual realizations of the binary mixtures in rod geometry. Analytic solutions are then obtained for the forward and backward directed fluxes on a given realization, now viewed as a deterministic medium with alternating layers of the two materials with known interface locations. Finally, material averaged scalar fluxes are obtained using these sampling schemes with spatially linear and quadratic chord lengths and used to assess the accuracy of the previously obtained LP-model results.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗