ItemProduction of advanced gaseous biomethane transport fuel in an integrated circular bioenergy system(Environmental Protection Agency, 2023-04) Kang, Xihui; Lin, Richen; Wu, Benteng; Dobson, Alan; Murphy, Jerry D.; Environmental Protection AgencyThis report proposes an anaerobic digestion (AD)-centred integrated circular bioeconomy system for the production of advanced fuels (biomethane or biomethanol), medium-chain fatty acids (such as caproic acid), biofertiliser and biochar (with potential application for negative emission technology). ItemUsing model selection and reduction to develop an empirical model to predict energy consumption of a CNC machine(Springer Nature Switzerland AG, 2022-10-17) Morris, Liam; Clancy, Rose; Hryshchenko, Andriy; O’Sullivan, Dominic; Bruton, Ken; Margaria, Tiziana; Steffen, Bernhard; Horizon 2020With an ever growing need to reduce energy consumption in the manufacturing industry, process users need to become more aware on how production impacts energy consumption. Computer numerically controlled (CNC) machining tools are a common manufacturing apparatus, and they are known to be energy inefficient. This paper describes the development of an empirical energy consumption model of a CNC with the aim of predicting energy consumption based on the number of parts processed by the machine. The model can then be deployed as part of a decision support (DS) platform, aiding process users to reduce consumption and minimise waste. In using the Calibrated Model Method, the data undergoes initial preparation followed by exploratory data analysis and subsequent model development via iteration. During this analysis, relationships between parameters are explored to find which have the most significant on energy consumption. A training set of 191 datapoints yielded a linear correlation coefficient of 0.95, between the power consumption and total units produced. RMSE, MAPE and MBE validation test yielded results of 0.198, 6.4% and 2.66% respectively. ItemEV specific time-of-use rates analysis for workplace charging(Institute of Electrical and Electronics Engineers (IEEE), 2021-08-02) Kucuksari, Sadik; Erdogan, Nuh; Sustainable Energy Authority of IrelandEV specific time-of-use rate plans have been recently introduced by several utilities to overcome the demand charge issue that is the main barrier impeding EV growth in the commercial and industrial sector. This study analyses two EV specific TOU rates in place from a customer and the grid perspectives. The analysis relies on a developed optimal cost model with coordinated charging strategies that minimizes the total cost of a workplace charging station over its lifetime. From a customer perspective, it is shown that the cost benefits are not always achievable and depends on the rates provided. From the grid perspective, the peak demand is found to be increased. Thus, the EV specific rates may not always provide an efficient use of the grid assets. ItemLooking for a simplified approach for the propagation of systematic uncertainty in the motion response of a floater(IOP Publishing, 2022-11) Gueydon, S.; Lyden, Eoin; Judge, Frances M.; O'Shea, Michael; Murphy, Jimmy; Horizon 2020This new research considers the 3 main motions of the moored floater (surge, heave and pitch) in head waves and it explores ways to estimate the systematic uncertainties on the RAOs, and 2 other metrics for these signals. Based on linear hydrostatics and the linear potential flow theory, simple relations can be found that bind the main characteristics of a floater. These relations are transformed using linear algebra to express how uncertainty bias on the main characteristics of the tested system can be propagated to the motion responses of the floater. Thanks to this approach, variations of the mooring stiffness, position of the centre of mass, radia of gyration can be represented through simple formulations that allow to very effectively assess their impact of the motion RAOs and other metrics. This approach is verified by comparing simulation and test results of the semisubmersible of the MARINET2 floating wind round robin campaign to approximations deduced from these theoretical relations. ItemCombined current and wind simulation for floating offshore wind turbines(IOP Publishing, 2022) Otter, Aldert; Desmond, C.; Flannery, Brian; Murphy, Jimmy; Science Foundation IrelandThis paper describes the validation of a novel method to simulate current loading on a floating offshore wind turbine model. A dynamic winch actuator is used to emulate the drag force of current on the platform of the model with a Software in the Loop application. Current loads are combined with wave- and wind loads. The results of experiments with physical current are validated against the results of experiments with simulated current. A method to simulate wave-current interactions is also described. The results show that the winch actuator can reliably emulate current induced drag forces in comparison with physical current under various combinations of environmental loads. Experimental repeatability of the response of the platform is shown to be superior when using simulated- rather than physical current.