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Full-Text Articles in Physical Sciences and Mathematics

Economic Analysis Of A Brackish Water Photovoltaic-Operated (Bwro-Pv) Desalination System, Ali Al-Karaghouli, Lawrence L. Kazmerski Oct 2010

Economic Analysis Of A Brackish Water Photovoltaic-Operated (Bwro-Pv) Desalination System, Ali Al-Karaghouli, Lawrence L. Kazmerski

Publications (E)

The photovoltaic (PV)-powered reverse-osmosis (RO) desalination system is considered one of the most promising technologies in producing fresh water from both brackish and sea water, especially for small systems located in remote areas. We analyze the economic viability of a small PV-operated RO system with a capacity of 5 m3/day used to desalinate brackish water of 4000 ppm total dissolve solids, which is proposed to be installed in a remote area of the Babylon governorate in the middle of Iraq; this area possesses excellent insolation throughout the year. Our analysis predicts very good economic and environmental benefits of …


User's Guide To Mbc3: Multi-Blade Coordinate Transformation Code For 3-Bladed Wind Turbine, G. S. Bir Sep 2010

User's Guide To Mbc3: Multi-Blade Coordinate Transformation Code For 3-Bladed Wind Turbine, G. S. Bir

Publications (E)

The dynamics of wind turbine rotor blades are conventionally expressed in rotating frames attached to the individual blades. The tower-nacelle subsystem though, sees the combined effect of all rotor blades, not the individual blades. Also, the rotor responds as a whole to excitations such as aerodynamic gusts, control inputs, and tower-nacelle motion—all of which occur in a nonrotating frame. Multi-blade coordinate transformation (MBC) helps integrate the dynamics of individual blades and express them in a fixed (nonrotating) frame. MBC involves two steps: transforming the rotating degrees of freedom and transforming the equations of motion. Reference 1 details the MBC operation. …


Green Power Marketing In The United States: A Status Report (2009 Data), Lori Bird, Jenny Sumner Sep 2010

Green Power Marketing In The United States: A Status Report (2009 Data), Lori Bird, Jenny Sumner

Publications (E)

This report documents green power marketing activities and trends in the United States. Aggregate green power sales data for all voluntary purchase markets across the United States are presented for 2009. The data presented in this report are based primarily on figures provided to NREL by utilities and independent renewable energy marketers. Because data cannot be obtained from all market participants, the estimates presented here likely represent an underestimate of the market size. Key trends identified in this year’s report include:
• In 2009, total retail sales of renewable energy in voluntary markets exceeded 30 million MWh, an increase of …


Further Developments On The Geothermal System Scoping Model, Mark Antkowiak, Rosemary Sargent, Jesse W. Geiger Jul 2010

Further Developments On The Geothermal System Scoping Model, Mark Antkowiak, Rosemary Sargent, Jesse W. Geiger

Publications (E)

The fields of well construction and engineering, power plant construction and engineering, and reservoir engineering often proceed independently of one another. Yet the subsystems of a geothermal plant with which each of these fields is concerned need to be integrated in order to create a viable geothermal power system and make enhanced (or engineered) geothermal systems (EGS) a technical and an economic reality. Furthermore, each of these subsystems need to be examined in the context of the overall power system to aid with plant construction, and–more salient to the U.S. Department of Energy–to help determine best investment of research dollars. …


Photovoltaics (Pv) As An Eligible Measure In Residential Pace Programs: Benefits And Challenges, Jason Coughlin Jun 2010

Photovoltaics (Pv) As An Eligible Measure In Residential Pace Programs: Benefits And Challenges, Jason Coughlin

Publications (E)

Property Assessed Clean Energy (PACE) financing is one of several new financial models broadening access to clean energy by addressing the barrier of initial capital cost. The majority of the PACE programs in the market today include PV as an eligible measure. PV appeals to homeowners as a way to reduce utility bills, self-generate sustainable power, increase energy independence and demonstrate a commitment to the environment. If substantial state incentives for PV exist, PV projects can be economic under PACE, especially when partnered with good net metering policies. At the same time, PV is expensive relative to other eligible measures …


Examination Of The Regional Supply And Demand Balance For Renewable Electricity In The United States Through 2015: Projecting From 2009 Through 2015 (Revised), Lori Bird, David Hurlbut, Pearl Donohoo, Karlynn Cory, Claire Kreycik Jun 2010

Examination Of The Regional Supply And Demand Balance For Renewable Electricity In The United States Through 2015: Projecting From 2009 Through 2015 (Revised), Lori Bird, David Hurlbut, Pearl Donohoo, Karlynn Cory, Claire Kreycik

Publications (E)

This report examines the balance between the demand and supply of new renewable electricity in the United States on a regional basis through 2015. It expands on a 2007 NREL study (Swezey et al. 2007) that assessed the supply and demand balance on a national basis. As with the earlier study, this analysis relies on estimates of renewable energy supplies compared to demand for renewable energy generation needed to meet existing state renewable portfolio standard (RPS) policies in 28 states, as well as demand by consumers who voluntarily purchase renewable energy. However, it does not address demand by utilities that …


Wind Energy Workforce Development: A Roadmap To A Sustainable Wind Industry, Ian Baring-Gould, Marguerite Kelly May 2010

Wind Energy Workforce Development: A Roadmap To A Sustainable Wind Industry, Ian Baring-Gould, Marguerite Kelly

Publications (E)

As the United States moves toward greatly expanded wind energy use, the need for skilled workers at all industry levels has been repeatedly identified as a critical issue. Additionally, if the industry and nation wish to capitalize on this rapid industry growth by becoming a major international green technology exporter, reversing current educational trends away from science, engineering, and technical skills must be achieved.

This poster provides an overview of the educational infrastructure and expected industry needs through a discussion of the activities to train workers while addressing issues for each of the education sectors, leading to the development of …


Voluntary Green Power Market Forecast Through 2015, Lori Bird, Ed Holt, Jenny Sumner, Claire Kreycik May 2010

Voluntary Green Power Market Forecast Through 2015, Lori Bird, Ed Holt, Jenny Sumner, Claire Kreycik

Publications (E)

Voluntary markets for renewable energy in which consumers purchase renewable energy from their electricity providers or from renewable energy certificate (REC) marketers have existed for more than a decade. Going forward, various factors will influence the development of these markets, including potential climate policies, state and federal renewable portfolio standards (RPS), renewable energy prices, the level of consumer interest in purchasing green power, and the interest on the part of utilities in offering new green options and in continuing to promote existing programs.

This report presents estimates of voluntary market demand for renewable energy or green power through 2015. The …


Solar Power And The Electric Grid, Energy Analysis, Nrel Energy Analysis Mar 2010

Solar Power And The Electric Grid, Energy Analysis, Nrel Energy Analysis

Publications (E)

In today’s electricity generation system, different resources make different contributions to the electricity grid. This fact sheet illustrates the roles of distributed and centralized renewable energy technologies, particularly solar power, and how they will contribute to the future electricity system. The advantages of a diversified mix of power generation systems are highlighted.


Barrier Coatings For Thin Film Solar Cells: Final Subcontract Report, L. C. Olsen Mar 2010

Barrier Coatings For Thin Film Solar Cells: Final Subcontract Report, L. C. Olsen

Publications (E)

This program has involved investigations of the stability of CdTe and copper-indium-gallium-diselenide (CIGS) solar cells under damp heat conditions and effects of barrier coatings. CdTe and CIGS cells were subjected to environmental conditions characterized by 60ºC and 90% relative humidity (60/90), and to some extent 85ºC and 85 % relative humidity (85/85). Barrier coating technology developed at PNNL for OLEDs was used to investigate approaches to encapsulation of the two types of thin film solar cells. Moisture barriers consisting of multi-layer coatings involving alternating layers of polymer and aluminum oxide were deposited directly onto the front surface of CIGS cells …


Development Of Regional Wind Resource And Wind Plant Output Datasets: Final Subcontract Report, 3tier Mar 2010

Development Of Regional Wind Resource And Wind Plant Output Datasets: Final Subcontract Report, 3tier

Publications (E)

This is the Final Report for the project “Development of Regional Wind Resource and Wind Plant Output Datasets“(NREL subcontract number: AAM-8-77556-01 under prime contract number: DE-AC36-99GO10337). The report covers the period of the contract from October 15, 2007 through March 15, 2009. The final delivered outcomes of this project include:

• This report detailing the work produced.

• 30 validation reports for the purpose of tuning the mesoscale models.

• The numerical weather prediction (NWP) simulations for 2004-2006 in NetCDF format with a spatial resolution of one arc-minute and a temporal resolution of ten minutes.

• 30,544 original sites and …


Preliminary Investigation Of Methods For Correcting For Variations In Solar Spectrum Under Clear Skies, B. Marion Mar 2010

Preliminary Investigation Of Methods For Correcting For Variations In Solar Spectrum Under Clear Skies, B. Marion

Publications (E)

Two types of methods were evaluated for correcting the short-circuit current of photovoltaic (PV) modules for variations in the solar spectrum under clear skies: (1) empirical relationships based on air mass, and (2) use of spectral irradiance models and PV module spectral response data. Methods of the first type were the Sandia absolute air-mass function, or f(AM(a)), and the CREST air-mass function, or f(AM). The second type used SEDES2 and SMARTS spectral irradiance models. The methods were evaluated using data recorded during June, September, and December 2008 at the National Renewable Energy Laboratory and during June 2008 at the Florida …


Solar Eclipse Monitoring For Solar Energy Applications Using The Solar And Moon Position Algorithms, Ibrahim Reda Mar 2010

Solar Eclipse Monitoring For Solar Energy Applications Using The Solar And Moon Position Algorithms, Ibrahim Reda

Publications (E)

This report includes a procedure for implementing an algorithm (described by Jean Meeus [1]) to calculate the Moon’s zenith angle with uncertainty of ±0.001° and azimuth angle with uncertainty of ±0.003°. The step-by-step format presented here simplifies the complicated steps Meeus describes to calculate the Moon’s position, and focuses on the Moon instead of the planets and stars. It also introduces some changes to accommodate for solar radiation applications. These include changing the direction of measuring azimuth angles from north and eastward instead of from south and eastward, and the direction of measuring the observer’s geographical longitude to be measured …


Consortia Focused On Photovoltaic R&D, Manufacturing, And Testing: A Review Of Existing Models And Structures, Charlie Coggeshall, Robert M. Margolis Mar 2010

Consortia Focused On Photovoltaic R&D, Manufacturing, And Testing: A Review Of Existing Models And Structures, Charlie Coggeshall, Robert M. Margolis

Publications (E)

As the U.S. Department of Energy's (DOE's) Solar Energy Technologies Program prepares to initiate a new cost-shared research and development (R&D) effort on photovoltaic (PV) manufacturing, it is useful to review the experience to date with consortia focused on PV R&D, manufacturing, and testing. Information was gathered for this report by conducting interviews and accessing Web sites of 14 U.S. consortia and four European consortia, each with either a primary focus on or an emerging interest in PV technology R&D, manufacturing, or testing. Additional input was collected from several workshops held by the DOE and National Academy of Sciences (NAS) …


The Value Of Concentrating Solar Power And Thermal Energy Storage, Ramteen Sioshansi, Paul Denholm Feb 2010

The Value Of Concentrating Solar Power And Thermal Energy Storage, Ramteen Sioshansi, Paul Denholm

Publications (E)

This paper examines the value of concentrating solar power (CSP) and thermal energy storage (TES) in four regions in the southwestern United States. Our analysis shows that TES can increase the value of CSP by allowing more thermal energy from a CSP plant’s solar field to be used, by allowing a CSP plant to accommodate a larger solar field, and by allowing CSP generation to be shifted to hours with higher energy prices. We analyze the sensitivity of CSP value to a number of factors, including the optimization period, price and solar forecasting, ancillary service sales, capacity value and dry …


Doe Request For Information (Rfi) De-Foa-0000153 Pv Manufacturing Initiative: Summary Report, National Renewable Energy Laboratory Feb 2010

Doe Request For Information (Rfi) De-Foa-0000153 Pv Manufacturing Initiative: Summary Report, National Renewable Energy Laboratory

Publications (E)

Clean Cities hosts a collection of tools on the exploring concepts for a “PV Manufacturing Initiative” to facilitate the development of a strong photovoltaic (PV) manufacturing industry in the United States. As an integral part this effort, and to inform the creation of a new funding opportunity in this area, DOE sought feedback from the PV industry.

This document summarizes the results of the PV Manufacturing Request for Information (RFI), DE-FOA-0000153. (See Attachment 1.) The RFI was posted on http://www.grants.gov on 4 September 2009 and the NREL Web site on 9 September 2009. Respondents were asked to submit RFI inputs …


Updated U.S. Geothermal Supply Curve, Chad Augustine, Katherine R. Young, Arlene Anderson Feb 2010

Updated U.S. Geothermal Supply Curve, Chad Augustine, Katherine R. Young, Arlene Anderson

Publications (E)

This paper documents the approach used to update the U.S. geothermal supply curve. The geothermal supply curve analysis undertaken in this study estimates the supply of electricity generation potential from geothermal resources in the United States and the levelized cost of electricity (LCOE), capital costs, and operating and maintenance costs associated with developing these geothermal resources. The supply curve data are used as input to annual reporting by the U.s. Department of Energy (DOE) under the Government Performance and Results Act of 1993, the DOE portfolio development support processes, and market penetration models in support of other DOE analyses. Supply …


Characterization Of Winds Through The Rotor Plane Using A Phased Array Sodar And Recommendations For Future Work, Regina Anne Deola Feb 2010

Characterization Of Winds Through The Rotor Plane Using A Phased Array Sodar And Recommendations For Future Work, Regina Anne Deola

Publications (E)

Portable remote sensing devices are increasingly needed to cost effectively characterize the meteorology at a potential wind energy site as the size of modern wind turbines increase. A short term project co-locating a Sound Detection and Ranging System (SODAR) with a 200 meter instrumented meteorological tower at the Texas Tech Wind Technology Field Site was performed to collect and summarize wind information through an atmospheric layer typical of utility scale rotor plane depths. Data collected identified large speed shears and directional shears that may lead to unbalanced loads on the rotors. This report identifies suggestions for incorporation of additional data …


Report On The U.S. Doe Geothermal Technologies Program's 2009 Risk Analysis, Katherine R. Young, Chad Augustine, Arlene Anderson Feb 2010

Report On The U.S. Doe Geothermal Technologies Program's 2009 Risk Analysis, Katherine R. Young, Chad Augustine, Arlene Anderson

Publications (E)

The U.S. Department of Energy (DOE) Geothermal Technologies Program (GTP or “the Program”) conducted a detailed risk analysis of their annual research, development, and demonstration (RD&D) portfolio. The Program worked with the National Renewable Energy Laboratory (NREL) to implement a probabilistic risk analysis of the GTP-sponsored RD&D, primarily enhanced geothermal systems (EGS) in accordance with Program budget authority. EGS technologies are in the early stages of development, and GTP-sponsored, multi-year demonstration projects are now underway to demonstrate technical feasibility, reduce risk for industry, and improve EGS best practices. The risk analysis examined estimates of improvement potential for two metric types: …


Wind For Schools: A Wind Powering America Project, National Renewable Energy Laboratory Jan 2010

Wind For Schools: A Wind Powering America Project, National Renewable Energy Laboratory

Publications (E)

Energy is largely taken for granted within our society, but that perception is changing as the economic and environmental impacts of our current energy structure are more widely understood. The U.S. Department of Energy’s (DOE’s) Wind Powering America program sponsors the Wind for Schools Project to raise awareness in rural America about the benefits of wind energy while simultaneously developing a wind energy knowledge base in the United States to educate future leaders of our communities, states, and nation about the importance of renewable energy.

The three primary project goals of the Wind for Schools Project are to:

• Engage …


Concentrating Solar Power Commercial Application Study: Reducing Water Consumption Of Concentrating Solar Power Electricity Generation, U.S. Department Of Energy Jan 2010

Concentrating Solar Power Commercial Application Study: Reducing Water Consumption Of Concentrating Solar Power Electricity Generation, U.S. Department Of Energy

Publications (E)

This report discusses potential methods to reduce water consumption associated with CSP. Four main concentrating solar power technologies are described in this report: parabolic troughs, linear Fresnel, power towers, and dish/engine. Parabolic troughs are the most commercially available technology. Linear Fresnel and power tower technologies are presently being planned as commercial plants, but none have yet been built in the U.S. The first three of these technologies use the heat collected from the sun to power conventional Rankine steam cycles, similar to those used for coal and nuclear plants. Steam cycle power plants require cooling to function (cooling is needed …


The Role Of Energy Storage With Renewable Electricity Generation, Paul Denholm, Erik Ela, Brendan Kirby, Michael Milligan Jan 2010

The Role Of Energy Storage With Renewable Electricity Generation, Paul Denholm, Erik Ela, Brendan Kirby, Michael Milligan

Publications (E)

Renewable energy sources, such as wind and solar, have vast potential to reduce dependence on fossil fuels and greenhouse gas emissions in the electric sector. Climate change concerns, state initiatives including renewable portfolio standards, and consumer efforts are resulting in increased deployments of both technologies. Both solar photovoltaics (PV) and wind energy have variable and uncertain (sometimes referred to as “intermittent”) output, which are unlike the dispatchable sources used for the majority of electricity generation in the United States. The variability of these sources has led to concerns regarding the reliability of an electric grid that derives a large fraction …


Analysis Of Hybrid Hydrogen Systems: Final Report, J. Dean, R. Braun, D. Munoz, M. Penev, C. Kinchin Jan 2010

Analysis Of Hybrid Hydrogen Systems: Final Report, J. Dean, R. Braun, D. Munoz, M. Penev, C. Kinchin

Publications (E)

This project examined biomass pathways for hydrogen production and how they can be hybridized to support renewable electricity generation. The project considered many potential hybrid systems before narrowing the focus to two. The systems were studied in detail for process feasibility and economic performance. The best-performing system was estimated to produce hydrogen at a cost ($1.67/kg) within range of the Department of Energy target for central biomass-derived hydrogen production, while also providing value-added energy services to the electric grid.


2008 Solar Technologies Market Report, U.S. Department Of Energy Jan 2010

2008 Solar Technologies Market Report, U.S. Department Of Energy

Publications (E)

This report focuses on the U.S. solar electricity market, including photovoltaic (PV) and concentrating solar power (CSP) technologies. The report provides an overview of global and U.S. installation trends. It also presents production and shipment data, material and supply chain issues, and solar industry employment trends. It also presents cost, price, and performance trends; and discusses policy and market drivers such as recently passed federal legislation, state and local policies, and developments in project financing. The final chapter provides data on private investment trends and near-term market forecasts.


Nrel: A Year In Clean Energy Innovations: A Review Of Nrel's Feature Stories, National Renewable Energy Laboratory Jan 2010

Nrel: A Year In Clean Energy Innovations: A Review Of Nrel's Feature Stories, National Renewable Energy Laboratory

Publications (E)

The National Renewable Energy Laboratory (NREL) is the nation’s primary laboratory for renewable energy and energy efficiency research and development.

NREL’s mission and strategy are focused on advancing the U.S. Department of Energy’s and our nation’s energy goals. The laboratory’s scientists and researchers support critical market objectives to accelerate research from scientific innovations to market-viable alternative energy solutions. At the core of this strategic direction are NREL’s research and technology development competencies. These areas span from understanding renewable resources for energy, to the conversion of these resources to renewable electricity and fuels, and ultimately to the use of renewable electricity …


Green Initiatives, Paul Andricopulos, Ned Thomas Jan 2010

Green Initiatives, Paul Andricopulos, Ned Thomas

Publications (E)

City practices incorporating energy conservation methods.


Wind Powering America: Fy09 Activities Summary, National Renewable Energy Laboratory Jan 2010

Wind Powering America: Fy09 Activities Summary, National Renewable Energy Laboratory

Publications (E)

The Wind Powering America FY09 Activities Summary reflects the accomplishments of state Wind Working Groups, WPA programs at the National Renewable Energy Laboratory, and partner organizations.