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.
Akhavan A.,Aws Truepower |
Rajabipour F.,Pennsylvania State University
Journal of Materials in Civil Engineering | Year: 2017
Cracks in concrete accelerate mass transport and shorten the service life of structures. In this study, cracks were physically simulated using a Plexiglas parallel-plate setup with adjustable distance between the plates (to achieve various crack widths) and with two distinct crack wall roughness values. Transport properties of such simulated cracks were measured and linked to crack geometry. Saturated permeability and ion diffusion coefficient of cracks were measured using constant head permeability test, electrical migration test, and electrical impedance spectroscopy. The results showed that the permeability coefficient of a crack is highly dependent on the crack width square, and to a lesser extent, on the crack tortuosity and wall surface roughness. The result of migration and impedance tests showed that crack diffusivity is only slightly affected by crack width and only for cracks tighter than 90 μm. Generally, crack diffusivity was found to be similar to the pore solution diffusivity, multiplied by a crack connectivity coefficient (βcr); the latter can be measured from an electrical conductivity test. © 2017 American Society of Civil Engineers.
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.
Agency: European Commission | Branch: FP7 | Program: CP | Phase: OCEAN.2011-1 | Award Amount: 6.45M | Year: 2012
The rational exploitation of oceans space and resources is increasingly seen as crucial to enhance European competitiveness in key areas such as Renewable Energy and Aquaculture. The H2OCEAN consortium aims at developing an innovative design for an economically and environmentally sustainable multi-use open-sea platform. The H2OCEAN platform will harvest wind and wave power, using part of the energy on-site for multiple applications including a multi-trophic aquaculture farm, and convert on-site the excess energy into hydrogen that can be stored and shipped to shore as green energy carrier. The project builds on already on-going R&D and commercial activities of a partnership involving European leading industrial and academic partners from 5 countries within the fields of renewable energy, fish farming, hydrogen generation, maritime transports and related research disciplines. The unique feature of the H2OCEAN concept, besides the integration of different activities into a shared multi-use platform, lies in the novel approach for the transmission of offshore-generated renewable electrical energy through hydrogen. This concept allows effective transport and storage the energy decoupling energy production and consumption, thus avoiding the grid imbalance problem inherent to current offshore renewable energy systems. Additionally, this concept also circumvents the need for a cable transmission system which takes up a significant investment share for offshore energy generation infrastructures, increasing the price of energy. The envisaged integrated concept will permit to take advantage of several synergies between the activities within the platform significantly boosting the Environmental, Social and Economic potential impact of new maritime activities, increasing employment and strengthening European competitiveness in key economic areas.
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.
Beaucage P.,Aws Truepower |
Brower M.C.,Aws Truepower |
Tensen J.,Aws Truepower
Wind Energy | Year: 2014
A wide range of numerical wind flow models are available to simulate atmospheric flows. For wind resource mapping, the traditional approach has been to rely on linear Jackson-Hunt type wind flow models. Mesoscale numerical weather prediction (NWP) models coupled to linear wind flow models have been in use since the end of the 1990s. In the last few years, computational fluid dynamics (CFD) methods, in particular Reynolds-averaged Navier-Stokes (RANS) models, have entered the mainstream, whereas more advanced CFD models such as large-eddy simulations (LES) have been explored in research but remain computationally intensive. The present study aims to evaluate the ability of four numerical models to predict the variation in mean wind speed across sites with a wide range of terrain complexities, surface characteristics and wind climates. The four are (1) Jackson-Hunt type model, (2) CFD/RANS model, (3) coupled NWP and mass-consistent model and (4) coupled NWP and LES model. The wind flow model predictions are compared against high-quality observations from a total of 26 meteorological masts in four project areas. The coupled NWP model and NWP-LES model produced the lowest root mean square error (RMSE) as measured between the predicted and observed mean wind speeds. The RMSE for the linear Jackson-Hunt type model was 29% greater than the coupled NWP models and for the RANS model 58% greater than the coupled NWP models. The key advantage of the coupled NWP models appears to be their ability to simulate the unsteadiness of the flow as well as phenomena due to atmospheric stability and other thermal effects. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.
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.
Hale E.,PNE Wind United States Inc. |
Fusina L.,Aws Truepower |
Brower M.,Aws Truepower
Wind Energy | Year: 2012
Over 50,000 NRG Systems #40 anemometers manufactured between May 2006 and December 2008 are potentially affected by a self-excited vibratory phenomenon termed dry friction whip (DFW). Affected anemometers can report wind speeds that are lower than true speeds by up to several percent. An analysis of post-deployment wind tunnel calibration tests on 99 anemometers manufactured in this period found that about 85% were affected by the problem. The mean wind speed bias between 4 and 16 m s -1 for most of the anemometers compared with pre-deployment tests ranged from -1.5% to -3.0%, and for some, the bias was as large as -6.5%. This finding was confirmed by field tests carried out for a mostly different sample of 53 potentially affected anemometers deployed in pairs with WindSensor P2546A or Vector A100LK anemometers. The field tests further indicated that the problem tends to worsen over time and varies with wind speed. However, the pattern of response varies greatly among anemometers. Based on this research, a method of adjusting data from NRG #40 anemometers manufactured in this period is proposed. The adjustments eliminate the mean bias in the field test data set, although significant scatter remains. Copyright © 2011 John Wiley & Sons, Ltd.
Schnitzer M.,Aws Truepower |
Johnson P.,Aws Truepower |
Thuman C.,Aws Truepower |
Freeman J.,Aws Truepower
Conference Record of the IEEE Photovoltaic Specialists Conference | Year: 2012
One of the most critical inputs to a photovoltaic (PV) energy model is the solar data set, which establishes the site's irradiance and weather variability. For long-term energy estimates, the solar data set is expected to represent the long-term climatological conditions on-site. While modeled solar data sets are available, the quality of these data vary by data source as well as regionally. The result of using a poor quality solar input data set is higher uncertainty in the energy production estimated from the model; conversely, a more accurate solar input data set can improve the confidence in the energy production estimate. As the solar industry begins to recognize the value of increasing confidence in PV performance modeling predictions, an increased focus on quality input solar data for PV energy estimation models is expected. Publicly available data sources were evaluated with respect to their suitability as input data for PV energy estimation. These included modeled data sources, publicly, available reference station data, and site-specific measured data. The results of a research study conducted at nine locations throughout the United States show that both the magnitude and the distribution of input solar data sets affect energy. The value of on-site solar data collection and its ability to reduce uncertainty from between 2% to 5% is presented, as demonstrated from a case study from a site in the United States Desert Southwest. © 2012 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.
Agency: GTR | Branch: Innovate UK | Program: | Phase: Innovation Voucher | Award Amount: 5.00K | Year: 2014
Bringing water to life - an innovative idea with the aim of overcoming the challenges of the effects of climate change and global warming on the supply of useable water. We aim to develop and harness existing technology to artificially release or tap into the massive reserve of the earths available water resource held in the atmosphere and direct this into environments where it is most needed. Our idea will revolutionise the availability of future water supplies; moving away from the politicised, commercialmanagement of water consumption to creating new and unrestricted sustainable reserves.