Time filter

Source Type

Albany, NY, United States

AWS Truepower, LLC is a renewable energy consulting company. It is headquartered in Albany, with offices in Denver, Brazil, Spain, Canada, and India.It offers a variety of services supporting renewable energy project development, and operations for offshore wind energy, onshore wind energy, and solar. These include resource mapping, energy assessment, project engineering, due diligence, performance evaluation, data monitoring, data collection, and power production forecasting. The company's general clients are developers, investors, governments and institutions. Wikipedia.

Montornes A.,University of Barcelona | Montornes A.,Aws Truepower | Codina B.,University of Barcelona | Zack J.W.,MESO Inc.
Atmospheric Chemistry and Physics | Year: 2015

Although ozone is an atmospheric gas with high spatial and temporal variability, mesoscale numerical weather prediction (NWP) models simplify the specification of ozone concentrations used in their shortwave schemes by using a few ozone profiles. In this paper, a two-part study is presented: (i) an evaluation of the quality of the ozone profiles provided for use with the shortwave schemes in the Advanced Research version of the Weather Research and Forecasting (WRF-ARW) model and (ii) an assessment of the impact of deficiencies in those profiles on the performance of model simulations of direct solar radiation. The first part compares simplified data sets used to specify the total ozone column in six schemes (i.e., Goddard, New Goddard, RRTMG, CAM, GFDL and Fu-Liou-Gu) with the Multi-Sensor Reanalysis data set during the period 1979-2008 examining the latitudinal, longitudinal and seasonal limitations in the ozone profile specifications of each parameterization. The results indicate that the maximum deviations are over the poles and show prominent longitudinal patterns in the departures due to the lack of representation of the patterns associated with the Brewer-Dobson circulation and the quasi-stationary features forced by the land-sea distribution, respectively. In the second part, the bias in the simulated direct solar radiation due to these deviations from the simplified spatial and temporal representation of the ozone distribution is analyzed for the New Goddard and CAM schemes using the Beer-Lambert-Bouguer law and for the GFDL using empirical equations. For radiative applications those simplifications introduce spatial and temporal biases with near-zero departures over the tropics throughout the year and increasing poleward with a maximum in the high middle latitudes during the winter of each hemisphere. © Author(s) 2015.

Molinari J.,Albany State University | Frank J.,Aws Truepower | Vollaro D.,Albany State University
Monthly Weather Review | Year: 2013

Tropical Storm Edouard (2002) experienced episodic outbreaks of convection downshear within the storm core in the presence of 11-15 m s-1 of ambient vertical wind shear. These outbreaks lasted 2-6 h and were followed by long periods with no deep convection. Flights from U.S. Air Force reconnaissance aircraft within the boundary layer were used to investigate the cause of one such oscillation. Low equivalent potential temperature θe air filled the boundary layer as convection ceased, creating a 4-6-K deficit in θe within the convective region. Soundings within 110 km of the center were supportive of convective downdrafts, with midlevel relative humidity below 15% and large downdraft CAPE. Deep convection ceased within 75 km of the center for more than 8 h. Tangential velocity reached hurricane force locally during the convective outbreak, then became nearly symmetric after convection stopped, arguably as a result of axisymmetrization, and the storm weakened. Nevertheless, the corresponding lack of convective downdrafts during this period allowed surface heat and moisture fluxes to produce substantial increases in boundary layer entropy. A new burst of convection followed. Consistent with recent papers it is argued that tropical cyclone intensification and decay can be understood as a competition between surface heat and moisture fluxes ("fuel") and lowentropy downdrafts into the boundary layer ("antifuel"). © 2013 American Meteorological Society.

Xia Y.,National Oceanic and Atmospheric Administration | Xia Y.,EMC | Mitchell K.,National Oceanic and Atmospheric Administration | Ek M.,National Oceanic and Atmospheric Administration | And 11 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2012

This is the second part of a study on continental-scale water and energy flux analysis and validation conducted in phase 2 of the North American Land Data Assimilation System project (NLDAS-2). The first part concentrates on a model-by-model comparison of mean annual and monthly water fluxes, energy fluxes and state variables. In this second part, the focus is on the validation of simulated streamflow from four land surface models (Noah, Mosaic, Sacramento Soil Moisture Accounting (SAC-SMA), and Variable Infiltration Capacity (VIC) models) and their ensemble mean. Comparisons are made against 28-years (1 October 1979-30 September 2007) of United States Geological Survey observed streamflow for 961 small basins and 8 major basins over the conterminous United States (CONUS). Relative bias, anomaly correlation and Nash-Sutcliffe Efficiency (NSE) statistics at daily to annual time scales are used to assess model-simulated streamflow. The Noah (the Mosaic) model overestimates (underestimates) mean annual runoff and underestimates (overestimates) mean annual evapotranspiration. The SAC-SMA and VIC models simulate the mean annual runoff and evapotranspiration well when compared with the observations. The ensemble mean is closer to the mean annual observed streamflow for both the 961 small basins and the 8 major basins than is the mean from any individual model. All of the models, as well as the ensemble mean, have large daily, weekly, monthly, and annual streamflow anomaly correlations for most basins over the CONUS, implying strong simulation skill. However, the daily, weekly, and monthly NSE analysis results are not necessarily encouraging, in particular for daily streamflow. The Noah and Mosaic models are useful (NSE > 0.4) only for about 10% of the 961 small basins, the SAC-SMA and VIC models are useful for about 30% of the 961 small basins, and the ensemble mean is useful for about 42% of the 961 small basins. As the time scale increases, the NSE increases as expected. However, even for monthly streamflow, the ensemble mean is useful for only 75% of the 961 small basins. Copyright 2012 by the American Geophysical Union.

Bergeron T.,INRS - Institute National de la Recherche Scientifique | Bernier M.,INRS - Institute National de la Recherche Scientifique | Chokmani K.,INRS - Institute National de la Recherche Scientifique | Lessard-Fontaine A.,INRS - Institute National de la Recherche Scientifique | And 2 more authors.
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2011

As the number of operational wind scatterometers is getting smaller, other sources of spaceborne sensors are now included in global wind mapping. One of the prominent sensors is the Synthetic Aperture Radar (SAR). Besides serving as a generic scatterometer, SAR systems are the only type of radar systems that can provide sub-km resolution sea surface wind data and offers near shore mapping capability. This unique feature is important for assessing the offshore wind resources. As an important source of renewable energy, offshore wind farms are growing rapidly. Furthermore, recent research shows that the cross-polarization radar backscatter does not seem to saturate in high winds, and provides an excellent supplement for scatterometer wind sensing in storm conditions. The saturation issues of co-polarization radar returns have so far made it difficult to resolve wind speeds beyond roughly 20 m/s, or even less for lower incidence angles. The scope of this paper is to show the potential of RADARSAT-2's polarimetric modes for wind speed retrieval. RADARSAT-2 is the first operational fully polarimetric (HH VV HV VH) C-band satellite. Standard Quad-pol images have been collected in the St. Lawrence Gulf and compared against the Mont-Louis buoy and QuikSCAT scatterometer data. Co-polarization wind speeds were computed with CMOD-5 algorithms. A few polarization ratios were tested to determine the most suitable one for RADARSAT-2's HH polarization mode. For Cross-polarization, two different models were compared. Cross-polarization gives excellent results when wind exceeds 5 m/s. In general, SAR wind retrieval is suitable for resolution of 400 m. © 2008 IEEE.

Spreafico S.,Aws Truepower
Sulphur 2013 29th International Conference and Exhibition | Year: 2013

All sulphuric acid plant managers and operators are aware of what mist eliminators represent in their unit. Generally speaking, mist eliminators work satisfactorily in sulphuric acid applications but after years of operation, problems like pressure drop increase due to plugging, loss of efficiency or reentrainment might be faced by operators. With this paper we would like to summarize in an organic and logic way the main available techniques regarding mist elimination including Wet Electrostatic Precipitators, trying to give some hints on how to minimize those problems and considering where the technology is going in order to improve removal efficiency and mist eliminator reliability. New materials are coming out as an alternative to the existing ones. We think this is the right moment to take into consideration new technical solutions, which could improve the general efficiency of your plant. The first step, which is essential to mist elimination, would be to know the particle size distribution of mist to be removed. It is important to know deeply what is the process involved with mist creation, as mist size and distribution chiefly depends on operating conditions. After mist characterization, the right eliminator could be designed. A second step would be to get aware of actual available technology to best remove identified mist particles. There are a few parameters that have to be checked to do a good design (fiberbed velocity, type of fiberbed bed, materials, presence of dust and so on) which strongly depend on where mist eliminators have to be installed (drying tower, interpass tower or final absorption tower, SO2 purification) and on the operating conditions. The choice of the right parameters could make operators manage their plant easier and at much lower operating and maintenance costs.

Discover hidden collaborations