Commercial Grid Research Articles

Dosimetric characterization for GRID collimator-based spatially fractionated radiation therapy: Dosimetric parameter acquisition and machine interchangeability investigation.

The purpose of this study is to characterize the dosimetric properties of a commercial brass GRID collimator for high energy photon beams including 15 and 10 MV. Then, the difference in dosimetric parameters of GRID beams among different energies and linacs was evaluated. A water tank scanning system was used to acquire the dosimetric parameters, including the percentage depth dose (PDD), beam profiles, peak to valley dose ratios (PVDRs), and output factors (OFs). The profiles at various depths were measured at 100cm source to surface distance (SSD), and field sizes of 10×10 cm2 and 20×20 cm2 on three linacs. The PVDRs and OFs were measured and compared with the treatment planning system (TPS) calculations. Compared with the open beam data, there were noticeable changes in PDDs of GRID fields across all the energies. The GRID fields demonstrated a maximal of 3mm shift in dmax (Truebeam STX, 15MV, 10×10 cm2). The PVDR decreased as beam energy increases. The difference in PVDRs between Trilogy and Truebeam STx using 6MV and 15MV was 1.5%±4.0% and 2.1%±4.3%, respectively. However, two Truebeam linacs demonstrated less than 2% difference in PVDRs. The OF of the GRID field was dependent on the energy and field size. The measured PDDs, PVDRs, and OFs agreed with the TPS calculations within 3% difference. The TPS calculations agreed with the measurements when using 1mm calculation resolution. The dosimetric characteristics of high-energy GRID fields, especially PVDR, significantly differ from those of low-energy GRID fields. Two Truebeam machines are interchangeable for GRID therapy, while a pronounced difference was observed between Truebeam and Trilogy. A series of empirical equations and reference look-up tables for GRID therapy can be generated to facilitate clinical applications.

Battery Energy Storage Systems: A Review of Energy Management Systems and Health Metrics

With increasing concerns about climate change, there is a transition from high-carbon-emitting fuels to green energy resources in various applications including household, commercial, transportation, and electric grid applications. Even though renewable energy resources are receiving traction for being carbon-neutral, their availability is intermittent. To address this issue to achieve extensive application, the integration of energy storage systems in conjunction with these resources is becoming a recommended practice. Additionally, in the transportation sector, the increased demand for EVs requires the development of energy storage systems that can deliver energy for rigorous driving cycles, with lithium-ion-based batteries emerging as the superior choice for energy storage due to their high power and energy densities, length of their life cycle, low self-discharge rates, and reasonable cost. As a result, battery energy storage systems (BESSs) are becoming a primary energy storage system. The high-performance demand on these BESS can have severe negative effects on their internal operations such as heating and catching on fire when operating in overcharge or undercharge states. Reduced efficiency and poor charge storage result in the battery operating at higher temperatures. To mitigate early battery degradation, battery management systems (BMSs) have been devised to enhance battery life and ensure normal operation under safe operating conditions. Some BMSs are capable of determining precise state estimations to ensure safe battery operation and reduce hazards. Precise estimation of battery health is computed by evaluating several metrics and is a central factor in effective battery management systems. In this scenario, the accurate estimation of the health indicators (HIs) of the battery becomes even more important within the framework of a BMS. This paper provides a comprehensive review and discussion of battery management systems and different health indicators for BESSs, with suitable classification based on key characteristics.

Beam quality and the mystery behind the lower percentage depth dose in grid radiation therapy

Grid therapy recently has been picking momentum due to favorable outcomes in bulky tumors. This is being termed as Spatially Fractionated Radiation Therapy (SFRT) and lattice therapy. SFRT can be performed with specially designed blocks made with brass or cerrobend with repeated holes or using multi-leaf collimators where dosimetry is uncertain. The dosimetric challenge in grid therapy is the mystery behind the lower percentage depth dose (PDD) in grid fields. The knowledge about the beam quality, indexed by TPR20/10 (Tissue Phantom Ratio), is also necessary for absolute dosimetry of grid fields. Since the grid may change the quality of the primary photons, a new kq,q0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathbf{k}}_{\\mathbf{q},{\\mathbf{q}}_{0}}$$\\end{document} should be evaluated for absolute dosimetry of grid fields. A Monte Carlo (MC) approach is provided to resolving the dosimetric issues. Using 6 MV beam from a linear accelerator, MC simulation was performed using MCNPX code. Additionally, a commercial grid therapy device was used to simulate the grid fields. Beam parameters were validated with MC model for output factor, depth of maximum dose, PDDs, dose profiles, and TPR20/10. The electron and photon spectra were also compared between open and grid fields. The dmax is the same for open and grid fields. The PDD with grid is lower (~ 10%) than the open field. The difference in TPR20/10 of open and grid fields is observable (~ 5%). Accordingly, TPR20/10 is still a good index for the beam quality in grid fields and consequently choose the correct kq,q0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\mathbf{k}}_{\\mathbf{q},{\\mathbf{q}}_{0}}$$\\end{document} in measurements. The output factors for grid fields are 0.2 lower compared to open fields. The lower depth dose with grid therapy is due to lower depth fluence with scatter radiation but it does not impact the dosimetry as the calibration parameters are insensitive to the effective beam energies. Thus, standard dosimetry in open beam based on international protocol could be used.

Three-dimensional surface lattice plasmon resonance effect from plasmonic inclined nanostructures via one-step stencil lithography

Abstract Plasmonic nanostructures allow the manipulation and confinement of optical fields on the sub-wavelength scale. The local field enhancement and environmentally sensitive resonance characteristics provided by these nanostructures are of high importance for biological and chemical sensing. Recently, surface lattice plasmon resonance (SLR) research has attracted much interest because of its superior quality factor (Q-factor) compared to that of localized surface plasmon resonances (LSPR), which is facilitated by resonant plasmonic mode coupling between individual nanostructures over a large area. This advantage can be further enhanced by utilizing asymmetric 3D structures rather than low-height (typically height < ∼60 nm) structure arrays, which results in stronger coupling due to an increased mode volume. However, fabricating 3D, high-aspect ratio, symmetry-breaking structures is a complex and challenging process even with state-of-the-art fabrication technology. Here, we report a plasmonic metasurface of 3D inclined structures produced via commercial TEM grid–based stencil lithography with a Q-factor of 101.6, a refractive index sensitivity of 291 nm/RIU, and a figure of merit (FOM) of 44.7 in the visible wavelength range at a refractive index of 1.5 by utilizing the 3D SLR enhancement effect, which exceeds the performance of most LSPR systems (Q < ∼10). The symmetry-breaking 3D inclined structures that are fabricated by electron beam evaporation at an angle increase the polarizability of the metasurface and the directionality of the diffractively scattered radiative field responsible for SLR mode coupling. Additionally, we explore the role of spatial coherence in facilitating the SLR effect and thus a high-Q plasmonic response from the nanostructures. Our work demonstrates the feasibility of producing 3D inclined structure arrays with pronounced SLR enhancement for high biological sensitivity by utilizing the previously unexplored inclined stencil lithography, which opens the way to fabricate highly sensitive plasmonic metasurfaces with this novel simple technique.

Techno-economic feasibility analysis of a commercial grid-connected photovoltaic plant with battery energy storage-achieving a net zero energy system

Grid connected Photovoltaic (PV) plants with battery energy storage system, are being increasingly utilised worldwide for grid stability and sustainable electricity supplies. In this context, a comprehensive feasibility analysis of a grid connected photovoltaic plant with energy storage, is presented as a case study in India. A novel smart net-zero energy management system is developed to reduce grid and fossil fuel-based backup electricity consumption during power outages and peak load shaving by controlling peak load demand A life cycle cost-benefit and levelized cost of energy (LCoE) analysis, is presented for five optimised photovoltaic plants with battery energy storage systems, with and without net metering regimes. The Solar Labs and PVSyst softwares are used for system planning and energy generation estimation followed by HOMER grid software and Excel sheet-based financial models for system optimisation and cost-benefit analysis. The sensitivity analysis is carried out considering most sensitive parameters to identify the best option. The results found a 200 kWp photovoltaic plant with 250-kWh battery energy storage system with net metering, as the best-optimised option with energy generation cost of INR 4.21/kWh, with 6.15 years payback period. The study results can be followed for sustainable solar power generation for commercial grid connected PV power plants worldwide.

Smart home energy management and power trading optimization using an enhanced manta ray foraging optimization

This paper proposes a plan to manage energy consumption in residential areas using the demand response method, which allows electricity users to contribute to the reliability of the power system by controlling their usage. Due to the growing population, the residential sector consumes a significant amount of energy, and the objectives of this study are to lower electricity costs and the peak to average ratio, as well as reduce the amount of imported electricity from the grid. The study aims to maximize profit by properly utilizing renewable energy sources and addressing energy trading. The manta ray foraging optimization (MRFO) and long term memory MRFO (LMMRFO) algorithms are used to solve this problem. Firstly, the validation of the proposed LMMRFO technique is confirmed by seven benchmark functions and compared its results with the results of the well-known optimization algorithms including hunter prey optimization, gorilla troops optimizer, beluga whale optimization, and the original MRFO algorithm. Then, the performance of the LMMRFO is checked on the optimization of smart home energy management. In the suggested approach, a smart home decides whether to purchase or sell electricity from the commercial grid based on the cost, demand, and production of electricity from its own microgrid, which consists of a wind turbine and solar panels. Energy storage systems support the stable and dependable functioning of the power system since the solar panel and wind turbine only occasionally produce electricity. Through various case studies, the proposed plan is tested and found to be effective in reducing electricity costs and the peak to average ratio while maximizing profit. Furthermore, a comparative study is conducted to demonstrate the legality and effectiveness of LMMRFO and MRFO.

Demonstration Test of Triaxial Superconducting Cable System Installed in Commercial Chemical Plant Grid

A triaxial high-temperature superconducting (HTS) cable for practical cable systems was installed in the chemical plant of a private company (BASF Japan), and a large-scale demonstration test was performed. An HTS (REBa2Cu3O7-d) triaxial cable with a length of 200 m was used, and it was laid at a height of approximately 6 m above the ground and cooled using circulating liquid nitrogen. The test was performed from November 2020 to September 2021. In this paper, we report the results of the demonstration test and the energy-saving effects of the cable system.

Development of high-performance zinc-ion batteries: Issues, mitigation strategies, and perspectives

Zn-ion batteries (ZIBs) continue to attract attention for commercial grid storage systems and as alternatives to lithium-ion batteries owing to their safety, environmental friendliness, relatively high volumetric energy density, material availability, and lower production cost. Unfortunately, issues such as dendrite formation at the anode, cathode dissolution, and parasitic side reactions (such as hydrogen evolution and corrosion reactions) continue to plague this battery technology, thus hindering its practical application. In this review, we provide an in-depth understanding of the current issues that affect zinc-ion batteries and comprehensively discuss the issues affecting zinc anodes, cathodes, and electrolytes. Further, the current research focusing on mitigating these issues has been scrutinized. This review article presents recent perspectives on zinc-ion batteries regarding factors such as environmental friendliness, cost of development, and enhancing the cycle life of zinc-ion batteries to guide the future development of high-performance zinc-ion batteries.

Design of a gsm-based remotely operated electrical energy management system

Electrical energy is a scarce resource in most developing countries. This has prompted numerous research into ways in which commercially deployed wireless communication technologies can be used to monitor, control and manage such energy. Analysis of many of such electrical energy management systems reveal inherent complexities in their deployment and operation. This has therefore motivated the proposal of a remotely operated electrical energy management system (ROEEMS). The proposed system is designed to manage electrical energy from three different sources such as commercial grid, photovoltaic arrays, and portable generator, and give an output depending on requirements of its operator. ROEEMS has been designed to overcome some challenges in existing systems such as system complexity and security demands (as is typical of Internet and server-based systems). The proposed design allows ROEEMS to achieve a truly remote operation mode while requiring limited operator skills and a comparatively reduced cost of installation and operation.

Experimental characterization of a commercial wire grid polarizer as a polarizing beam splitter at 1.55 µm wavelength

A commercially available wire grid plate polarizer (Meadowlark IR VersaLight) is experimentally characterized for use as a polarizing beam splitter with variable incidence angles up to ± 50°. Five elements of this type are tested, and found to have an average pass-state transmittance of approximately 94% ± 2% for incidence angles up to ±30° and a block-state reflectance of approximately 92% ± 2% for all measured incidence angles. Polarizer orientation (with compensating adjustment of input linear polarization state) and propagation direction through the device were each found to cause no more than a 2% difference of transmission/reflection efficiency for incidence angles up to ±30°. Overall, this device was found to demonstrate high efficiency in both pass state transmittance and block state reflectance over a range of incidence angles and polarizer orientations, confirming its usability as a versatile polarizing beam splitter.

Design and test of a novel 1kw Stirling engine generator

This paper describes a practical design of a novel Stirling engine generator and 1kW machine test data. This machine’s configuration is a 4 cylinder double acting Stirling engine coupled with a Halback PM generator in line. This machine operates on the Stirling thermodynamic cycle and electromagnetic cycle established in 19th century by Carnot and Faraday. This machine’s unique function is bidirectional exchanging between thermal energy and electric power, as a same rotating direction of a same shaft. And the shaft speed can be controlled by three phases voltage source PWM inverter during both function such as the motor cooler mode and the engine generator mode. So, this unit can generate an electricity by using to many kinds of external heat source. As the heat source temperature changes as the shaft speed changes for the amount of absorbed heat changing in order to keep a cylinder temperature (700 ℃) and a heater tube temperature (<770 ℃). Consequently, the unit will achieve a highest efficiency keeping as a creep rapture strength limit level of the heater tubes. This unit has achieved 1.1 kW effective electric power, and 20.1% efficiency using LPG fuel, and 23.7 % thermal energy to electrical energy. This unit can connect to a commercial AC grid line by another inverter and, also connect a high voltage battery and a solar cell on the high voltage DC bus line in the PWM inverter.

Energy-Efficient Hybrid Powered Cloud Radio Access Network (C-RAN) for 5G

Owing to the ever-increasing energy consumption, energy efficiency (EE) is an important parameter for next generation 5G network. The Cloud Radio Access Network (C-RAN) is a viable solution for tackling 5G network problems in an energy-efficient manner. Integrating renewable energy with C-RAN can be a powerful tool for reducing operating costs and carbon dioxide emission. But, the regional unpredictability and intermittency nature of renewable energy can result in energy outages and worsening the service quality. As a consequence, the most reliable way is to combine commercial grid supplies with renewable energy. In this paper, we proposed a network model for the downlink C-RAN with hybrid power supplies. The goal of the proposed hybrid supply with solar and grid energy collaboration is to optimize the use of renewable solar energy by reducing grid Power Consumption (PC) and, most significantly, enhancing energy efficiency and preserving service quality. A comprehensive analysis is performed to evaluate EE performance of the proposed C-RAN under a variety of network settings. The numerical results affirm the proposed C-RAN models establishing a significant improvement in network EE compared to the conventional one.

A Method for Statistical Processing of Magnetic Field Sensor Signals for Non-Invasive Condition Monitoring of Synchronous Generators.

Condition monitoring of synchronous generators through non-invasive methods is widely requested by maintenance teams for not interfering the machine operation. Among the techniques used, external magnetic field monitoring is a recent strategy with great potential for detecting incipient faults. In this context, this paper proposes the application of a simple strategy with low computational cost to process data of external magnetic field time derivative signals for the purposes of condition monitoring and fault detection in synchronous machines. The information of interest is extracted from changes in the magnetic signature of the synchronous generator, obtained from frequency spectra of monitored signals using induction magnetic field sensors. The process forms a set of time series that reflects constructive and operational characteristics of the machine. The Shewhart control chart method is applied for anomaly detection in these time series, allowing the detection of changes in the machine magnetic signature. This method is employed in an algorithm for continuous condition monitoring of synchronous generators, presenting as output a global change indicator for the multivariable problem associated with magnetic signature monitoring. Correlation matrices are used to improve the algorithm response, filtering series with similar variation patterns associated with detected events. The proposed method is validated through tests on an experimental bench that allows the controlled imposition of faults in a synchronous generator. The proposed global change indicator allows the automatic detection of stator and rotor faults with the machine synchronized with the commercial power grid. The proposed methodology is also applied on data obtained from an equipment installed in a 305 MVA synchronous generator of a hydroelectric power plant where the evolution of an incipient fault, i.e., a mechanical vibration fault, has been detected.

A Novel Solution for Optimized Energy Management Systems Comprising an AC/DC Hybrid Microgrid System for Industries

A novel solution for optimized energy management comprising a microgrid system for industries in Pakistan is proposed. The proposed study considered microgrids based on photovoltaics, wind turbines, power storage systems, and dual-fuel (DF) generators as backup. A heuristic methodology with a cuckoo search algorithm (CSA) is presented for efficient power trading by scheduling machines. The study was conducted to prove that CSA is adaptable and flexible for self-governing choices for the efficient management and scheduling of machines and power trade between the microgrid and commercial grid. A mixed integer linear programming algorithm is introduced to optimize the system design problems that control decision making for the ideal operation management. A real-time pricing scheme is utilized for electricity price figures. The simulation results show the efficient performance of the proposed scheme to maximize profitability, reduction in electricity cost, and peak to average ratio. Furthermore, the proposed optimization technique was compared with a highly in-use strawberry algorithm to prove the supremacy of the proposed technique. The proposed efficient and robust energy management system was implemented in Shafi Dyeing Industry, Faisalabad, to validate the simulated model.

A Dosimetric Parameter Reference Look-Up Table for GRID Collimator-Based Spatially Fractionated Radiation Therapy.

Simple SummaryDose prescription for the inhomogeneous dosing in spatially fractionated radiation therapy (SFRT) is challenging, and further hampered by the inability of several planning systems to incorporate complex SFRT dose patterns. We developed dosing reference tables for an inventory of tumour scenarios and tested their accuracy with water phantom measurements of GRID therapy, delivered by a standard commercial GRID collimator. We find that dose heterogeneity parameters and EUD modeling are consistent across tumour sizes, configurations, and treatment depths. These results suggest that the developed reference tables can be used as a practical clinical resource for clinical decision-making on GRID therapy and to facilitate heterogeneity dose estimates in clinical patients when this commercially available GRID device is used.Computations of heterogeneity dose parameters in GRID therapy remain challenging in many treatment planning systems (TPS). To address this difficulty, we developed reference dose tables for a standard GRID collimator and validate their accuracy. The .decimal Inc. GRID collimator was implemented within the Eclipse TPS. The accuracy of the dose calculation was confirmed in the commissioning process. Representative sets of simulated ellipsoidal tumours ranging from 6–20 cm in diameter at a 3-cm depth; 16-cm ellipsoidal tumours at 3, 6, and 10 cm in depth were studied. All were treated with 6MV photons to a 20 Gy prescription dose at the tumour center. From these, the GRID therapy dosimetric parameters (previously recommended by the Radiosurgery Society white paper) were derived. Differences in D5 through D95 and EUD between different tumour sizes at the same depth were within 5% of the prescription dose. PVDR from profile measurements at the tumour center differed from D10/D90, but D10/D90 variations for the same tumour depths were within 11%. Three approximation equations were developed for calculating EUDs of different prescription doses for three radiosensitivity levels for 3-cm deep tumours. Dosimetric parameters were consistent and predictable across tumour sizes and depths. Our study results support the use of the developed tables as a reference tool for GRID therapy.

Grid-to-rod fretting wear study of SiC/SiC composite accident-tolerant fuel claddings using an autoclave fretting bench test

Grid-to-rod-fretting (GTRF) in pressurized water reactors (PWRs) is known to cause wear and surface damage on the fuel claddings, potentially leading to radioactive leakage. One of the accident-tolerant fuel (ATF) concepts is to use advanced cladding materials that could withstand higher temperatures. This study investigated the wear behavior of candidate silicon carbide (SiC)-based composite claddings with different levels of surface finish in fretting against a commercial ZIRLO alloy grid using a unique bench-scale autoclave GTRF rig. The experiments mimicked the environment in an industrial full-assembly PWR simulator. Fretting tests were conducted with a realistic load (∼0.5 N) in deionized water under a pressure of 20–23 bar at 204 °C for 100 h. While the SiC/SiC composite claddings showed significantly higher wear resistance than the commercial ZIRLO alloy cladding as expected, the smoother versions experienced surprisingly higher wear than the much softer counterface, ZIRLO grid. The wear mechanism of the SiC/SiC cladding was attributed to the SiC wear debris that was trapped at the fretting interface causing both 3-body and 2-body (embedded into the grid surface) abrasion of the cladding. Rougher SiC/SiC claddings had less material loss but caused more wear on the ZIRLO grid. Pre-oxidized ZIRLO grid showed better compatibility with the SiC/SiC cladding to protect both the cladding and grid as a result of reduced wear debris trapping.

Numerical Investigation of Controllable Parameters Effect on Nanofluid Flooding in a Random Pore Generated Porous Medium

This study simulates the enhanced oil recovery process using nanofluids into a microporous medium. To obtain the optimum values that affect this process, design experiments with the general factorial method was performed. Four parameters included type of nanoparticles and the base fluids, diameter, and volume fraction of nanoparticle were considered. The porous medium was created with the commercial grid generation tool and Fluent software was used to solve the governing equations. Comparison of numerical results with the experimental data illustrates that they are in good agreement. In addition, results show that clay nanoparticles with formation water have the greatest impact on the oil recovery factor compared to other nanofluids. Also the nanofluid with higher amounts of nanoparticles in the base fluid and smaller diameter have better performance in improving the oil recovery factor. Therefore, for having the maximum oil recovery factor, the best combination of parameters is clay nanoparticles with 2 nm diameter and 5 vol. % in formation water.

ASSiST - A Superconducting Fault Current Limiter in a Public Electric Power Grid

For installation in the public electric power grid of the city of Augsburg, Germany, a resistive superconducting fault current limiter (SFCL) was designed, constructed, tested and operated in the framework of a partially funded project &#x2018;ASSiST&#x2019;. Right from the beginning, it was agreed to aim for a prolonged operation even after closure of the project. This endeavor has been started due to a fundamental need to limit the prospective fault currents at a feeder point of the grid and in order to create long-term operational experience on a device seamlessly integrated into commercial grid components and switchgear, thus demonstrating a high level of readiness for widespread application. It revealed that the SFCL was of robust design &#x2013; withstanding all electrical tests including a special two-phase fault and sustaining stable cryogenic conditions even during partial outages of the cooling system &#x2013; and that the technology is reducing loss by shunt reactors. Furthermore, due to the control equipment on medium voltage level, valuable insights on grid behavior could be gained. The extended operation for 4 years has clearly shown the performance and robustness of SFCL technology in feeder points on MV level and provides a reference point for further commercialization.

Autoclave grid-to-rod fretting wear evaluation of a candidate cladding coating for accident-tolerant fuel

In pressurized water reactors (PWRs), water flow induced vibrations cause contact and rubbing between the fuel rods and the supporting grid, a phenomenon known as Grid-to-Rod-Fretting (GTRF). GTRF may produce progressive wear damage on the fuel claddings leading to subsequent leakage of radioactive fission products. Various accident-tolerant fuel (ATF) concepts are being developed for higher resistance to the high temperature steam and one approach is to apply a cladding coating. In this study, fretting wear behavior of a candidate Cr-coating was investigated using a unique bench-scale autoclave testing rig mimicking the environment in an industrial full-assembly PWR simulator. The contact was under a realistically low load (~0.5 N) lubricated by deionized water at a temperature of 204 °C under a pressure of 20-23 bars. Results demonstrated that the Cr-coating significantly improved the cladding's wear resistance when tested against a commercial ZIRLO grid with or without pre-oxidization. In addition, the Cr-coating also reduced wear on the non-oxidized ZIRLO grid but slightly increased the wear on the pre-oxidized grid.

Yield measurement is valuable for pricing beef carcasses

Context The most common way of pricing beef carcasses is through a price grid. Most processors make greater profit from higher-quality carcasses, which are those with higher meat yield and eating quality. Aims The aim of this study was to calculate the value of diverse carcasses and compare pricing mechanisms on their ability to discriminate variation in meat yield and predicted eating quality. Methods Hereford cross steer carcasses (153) were boned out to record saleable meat and yield. Six methods were used to calculate carcass price (AU$/kg). All were adjusted to the same average carcass value to allow comparisons, assuming that the overall payment does not change, but comparing the effect of having greater premiums and discounts. The six prices were based on a commercial grid, grid plus eating quality premium, yield of saleable meat only (constant price for all saleable meat), yield with eating quality premium, then the yield prices with optimum (quadratic) weight and fatness penalties based on grid optimums. Key results Measurements of meat quality (eye muscle area and marble score) or saleable meat yield accounted for no variation in the grid price. However, measurement of yield accounted for substantial variation in prices calculated from yield and eating quality. Conclusions The current grids do not encourage high-quality meat production and, assuming that yield and eating quality are important to processors, an actual measurement of yield is crucial to guide processing decisions (e.g. cutting plans) to maximise carcass value and feed market signals back to beef producers. Implications Improved measurement of meat yield is required if carcass prices are to reflect carcass quality or the potential value captured.