Navid Goudarzi

PHM based predictive maintenance optimization for offshore wind farms

In this paper, a simulation-based real options analysis (ROA) approach is applied to valuate the predictive maintenance options created by PHM for multiple turbines in offshore wind farms managed under outcome-based contracts known as power purchase agreements (PPAs). When a remaining useful life (RUL) is predicted for a subsystem in a single turbine, a predictive maintenance option is triggered. If predictive maintenance is implemented before the subsystem or turbine fails, the option is exercised; if the predictive maintenance is not implemented and the subsystem or turbine runs to failure, the option expires and the option value is zero. The time-history cost avoidance and cumulative revenue paths are simulated considering the uncertainties in wind and the RUL predictions. By valuating a series of European real options based on all possible predictive maintenance opportunities, the maintenance opportunity with the maximum value can be obtained. In a wind farm, there may be multiple turbines concurrently indicating RULs. To model multiple turbines managed via an outcome-based contract (PPA), the cumulative revenue and cost avoidance for each turbine depends on the operational state of the other turbines in the farm, the amount of energy that has been delivered and will be delivered by the whole farm. A case study is presented that determines the optimum predictive maintenance opportunity for a farm under a PPA, the optimum predictive maintenance opportunity for the same farm managed via an as-delivered contract, and the optimum predictive maintenance opportunities for individual turbines managed independently.

CFD and Control Analysis of a Smart Hybrid Vertical Axis Wind Turbine

Wind energy has become a dominant source of renewable energy during the past decade. Current hybrid wind turbines are primarily designed and manufactured based on a combination of aerodynamic prope ...

Computational Fluid Dynamics Methods for Wind Turbines Performance Analysis

Improving the energy efficiency of wind turbines and capacity factor of wind farms is a continuous research subject in recent years. While the maximum energy conversion efficiency of different wind harnessing machines has a range from 0.59 to 0.70, actual commercial-scale efficiency of these machines is less than 0.5 in the current optimum designs. To improve this value, wind harnessing machine designs with improved efficiency and reliability values in wind farms with high capacity factors in both onshore and offshore applications are needed.

Product-Service Systems Under Availability-Based Contracts: Maintenance Optimization and Concurrent System and Contract Design

Product-service systems (PSSs) are the result of a shifting business focus from designing and selling physical products, to selling a system consisting of products and services in an ongoing relationship with the customer that fulfills customer satisfaction. A PSS contract can take several forms (e.g., fixed price, capability-contract, and availability-based). The focus of this chapter is on PSSs that use availability-based contracts. In these cases the customer does not purchase the product, instead they purchase the utility of the product and the availability of service in order to obtain a lower cost while still meeting their needs. This chapter addresses the optimization of system maintenance activities, and the concurrent design of the PSS and the contract.

An Introduction to Flow Field Analysis Models for Wind Harnessing Machines

Even though wind turbine industry is a mature technology, it fails in standalone power systems, especially in low wind speed regimes. Vertical axis wind turbine (VAWT)/unconventional configurations have shown a great potential for generating electricity in an expanded range of operation in residential, commercial, and off-grid property applications. Their low power coefficient values and high cost of energy at different wind speeds should be improved through more comprehensive studies. In this work, novel wind harnessing configurations to fill some of the existing wind turbine performance gaps are reviewed and compared. A number of flow field analysis models for wind harnessing machines is explored. The results show the strength of VAWTs compared to conventional horizontal axis wind turbines. Also, it introduces appropriate models for flow field analysis of VAWTs/unconventional wind harnessing machines to obtain an enhanced aerodynamic performance, to the greatest extent for both onshore and offshore applications. Finally, new designs to further expand the operational range of wind harnessing machines at a lower cost are proposed.Copyright

Cost Performance Tradeoff Study of Power Generation From Wind

Health and environmental consequences of conventional fossil fuels are drawing more interest in expanding the use of renewable energy sources. The primary challenges in supplying the required electricity from wind are the variability, uncertainty, and the cost of electric power generation. An earlier paper presented the results of a system concept tradeoff using one-year wind/load data from Pennsylvania New Jersey Maryland Interconnection LLC (PJM). While one year results showed a wind plus natural gas system can reduce CO2 emission as much as 50% below that of an all-natural gas system with only a modest increase in system cost, typical power generation modeling extends to three years. In this work, the developed model is employed to estimate the magnitude of cost versus performance using three-year wind/load data at PJM in the United States and EirGrid in Ireland, and cost estimations published by the Energy Information Agency. The year to year variation at each region is studied and compared with each other. Also, the curtailment curve obtained from three years wind/load data is compared with that from one year to access the variance. The grid-scale storage parameter variations are studied to estimate the generation cost with storage as a function of emission levels.© 2015 ASME