Wind turbine gearboxes are not always meeting 20-year design life. Premature failure of gearboxes increases cost of energy, turbine downtime, unplanned maintenance, gearbox replacement and rebuild, and increased warranty reserves. The problem is widespread, affects most Original Equipment Manufacturers, and is not caused by manufacturing practices. There is a need to improve gearbox reliability and reduce turbine downtime. The topics of this presentation are: GRC (Gearbox Reliability Collaborative) technical approach; Gearbox failure database; Recorded incidents summary; Top failure modes for bearings; Top failure modes for gears; GRC test gearbox; Bearing nomenclature; Test history; Real damage; Gear sets; Bearings; Observations; and Summary. 5 refs.

This presentation describes how you could conceivably allocate variability and reserve requirements, including how to allocate aggregation benefits. Conclusions of this presentation are: (1) Aggregation provides benefits because individual requirements are not 100% correlated; (2) Method needed to allocate reduced requirement among participants; (3) Differences between allocation results are subtle - (a) Not immediately obvious which method is 'better'; (b) Many are numerically 'correct', they sum to the physical requirement; (c) Many are not 'fair', Results depend on sub-aggregation and/or the order individuals are included; and (4) Vector allocation method is simple and fair.

Additional variability and uncertainty increase reserve requirements. In this light, this presentation discusses how use of generation reserves can be optimized for managing variability and uncertainty. Conclusions of this presentation are: (1) Provided a method for calculating additional reserve requirements due to wind and solar production; (2) Method is based on statistical analysis of historical time series data; (3) Reserves are dynamic, produced for each hour; (4) Reserve time series are calculated from and synchronized to simulation data; (5) PROMOD can not model directly, but workarounds exist for regulation and spin; and (6) Other production modeling packages have varying capability for reserves modeling.

This presentation describes how you economically manage integration costs of storage and variable generation.

This presentation details the Gearbox Reliability Collaborative Condition Monitoring program at NREL.

This presentation offers new data and statistical analysis of ramping, solar power, and weather patterns in operational systems.

This presentation looks at three aspects of the second use of PEV batteries: Competitive technology, revenue streams, and supply and demand.

An estimate of the total and recoverable geopressured geothermal resource of the fairways in the Wilcox and Frio formations is made using the current data available. The flow rate of water and methane for wells located in the geopressured geothermal fairways is simulated over a 20-year period utilizing the TOUGH2 Reservoir Simulator and research data. The model incorporates relative permeability, capillary pressure, rock compressibility, and leakage from the bounding shale layers. The simulations show that permeability, porosity, pressure, sandstone thickness, well spacing, and gas saturation in the sandstone have a significant impact on the percent of energy recovered. The results also predict lower average well production flow rates and a significantly higher production of natural gas relative to water than in previous studies done from 1975 to 1980. Previous studies underestimate the amount of methane produced with hot brine. Based on the work completed in this study, multiphase flow processes and reservoir boundary conditions greatly influence the total quantity of the fluid produced as well as the ratio of gas and water in the produced fluid.

This presentation describes how a new wholesale electricity market for energy imbalance ancillary services could be implemented and operated. Some conclusions of this presentation are: (1) Method for calculating additional reserve requirements due to wind and solar production; (2) EIM results in substantial reduction in reserves requirements and ramping demand; (3) Reduced participation reduces benefits for all but reduces the benefits to non-participants the most; (4) Full participation leads to maximum benefit across the Western Interconnection, up to 42% of total reserve requirement; and (5) Regional EIM implementations have smaller but substantial benefits.

This presentation offers new data and statistical analysis of wind power forecasting errors in operational systems.