Seminar Archive Summaries

Solar Energy Mini-Series: Solar PV Manufacturing -- U.S. Competitiveness in a Global Industry

Alan Goodrich, National Renewable Energy Laboratory

Monday, October 10, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All

Over the past five years, solar Photovoltaic (PV) module shipments from China and Taiwan has grown from 6% to 54% global market share, while the U.S. has slipped from 9% to 6% market share. Chinese PV companies have gained an international pole position, in part, by achieving the industry’s lowest silicon module manufacturing cost. There is also a clear strategic effort on the part of the Chinese government to drive an expansion into the high technology enterprises of the future, like solar PV by offering strong state support for export industries such as solar PV component manufacturing. Over the long term, however, there are many challenges facing the Chinese PV industry that will impact its ability to sustain its dominant position.

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American Public Opinion on Climate Change and Its Impact on Voting in Congressional and Presidential Elections: New Evidence from State and National Surveys

Jon Krosnick, Department of Communication, Stanford University

Monday, October 3, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All

In recent years, observers have speculated that the American public has become increasingly skeptical about the existence and potential threat of climate change and that the public desire for action by government on this issue has declined. In this talk, Jon Krosnick will present new survey evidence tracking public opinion in the nation and in Massachusetts to explore what changes have occurred in the entire population and in population subgroups. In addition, Dr. Krosnick will present the results of a new study examining whether candidates' positions on climate change policy have influenced their electoral success, using three methods of investigation: (1) analysis of the relation of candidate website statements on climate with the victory rates of Congressional candidates in 2010, (2) experiments embedded in surveys describing a hypothetical candidate running for a Senate seat, and (3) a statistical analysis predicting votes in the 2008 U.S. Presidential election using data collected from survey respondents before and after the election. The findings paint a portrait of the likely role of climate change in the upcoming elections.

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Solar Energy Mini-Series: The Opto-Electronic Physics That Just Broke the Efficiency Record in Solar Cells

Eli Yablonovitch, Electrical Engineering & Computer Sciences Dept., University of California-Berkeley

Monday, September 26, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All

The solar cell field is changing. We are finally approaching the Shockley-Queisser (SQ) limit for single junction solar cell ~33.5% efficiency under the standard solar spectrum. Previously, the record had been stuck at 25.1%, during 1990-2007. Why then the 8% discrepancy between the theoretical limit 33.5% versus the previously achieved efficiency?

It is usual to blame material quality. But in the case of GaAs double heterostructures, the material is almost ideal with an internal fluorescence yield of >99%. This deepens the puzzle as to why the full theoretical SQ efficiency was not achieved?

Counter-intuitively, efficient external fluorescence is a necessity for approaching the ultimate limits. Now new efficiency records are being broken. Alta Devices has reached 28.2%. A great Solar Cell also needs to be a great Light Emitting Diode.

Scenarios of the Global Climate Energy System

Keywan Riahi, Senior Research Scholar and Acting Leader of the Energy Program, International Institute for Applied Systems Analysis (IIASA)

Monday, May 23, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All

More than 300 energy experts collaborated over the last four years on the Global Energy Assessment (GEA). The Report, forthcoming in Summer 2011, aims at providing the technical and scientific basis for the evaluation of social, economic, technological, and environmental challenges linked to energy. This talk focuses on findings of the GEA energy scenario analysis. The scenarios explore transformative changes of the energy system in order to meet a range of sustainability objectives. Specifically, they assesses technical measures, policies, and related costs and benefits for providing almost universal access to affordable clean cooking fuel and electricity for the poor, limiting air pollution and health damages from energy use, improving energy security throughout the world, and limiting climate change to below 2C compared to preindustrial levels. Results from the scenario analysis indicate that the transformation towards ambitious sustainability objectives is technically possible, and that alternative combinations of resources, technologies, and policies are conceivable to attain the objectives. Three illustrative pathways (GEA-Supply, GEA-Mix, and GEA-Efficiency) are selected from a large ensemble of possible transformations. They depict salient branching points for policy implementation and highlight different degrees of freedom and routes to the sustainability objectives.

Powering the World for all Purposes With Wind, Water, and Sunlight

Mark Z. Jacobson, Department of Civil & Environmental Engineering, Stanford University

Monday, May 16, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All

This talk discusses a plan to power 100% of the world’s energy for all purposes with wind, water, and sunlight (WWS) within the next 20-40 years. The talk starts by reviewing and ranking major proposed energy-related solutions to global warming, air pollution mortality, and energy security while considering other impacts of the proposed solutions, such as on water supply, land use, resource availability, reliability, wildlife, and catastrophic risk. It then evaluates a scenario for powering the world on the energy options determined to be the best while also considering materials, transmission infrastructure, costs, and politics. The study concludes that powering the world with wind, water, and solar technologies, which are found to be the best when all factors are considered, is technically feasible but politically challenging. Relevant papers can be found at

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The Graduate School of Business' Knight Management Center: LEED + PV

Kathleen Kavanaugh, Program Director, Stanford Graduate School of Business

Bhima Sheridan, Jon Biegenzahn, and Ben Tarbell, Solar City 

Wednesday, May 11, 2011 | 04:15 PM - 05:15 PM | | Free and Open to All

Please note different time and location: Wednesday 5/11, 4:15-5:15pm at Knight Management Center C106


An interactive presentation on the design and implementation of the Graduate School of Business' goals for sustainability at it's new Knight Management Center campus.  Kathleen Kavanaugh, LEED AP and Program Director at the Knight Management Center will discuss the vision for the campus, which is seeking LEED Platinum certification from the United States Green Building Council.  Bhima Sheridan will talk about Solar City's approach to engineering the photovoltaic system and integrating it with the building's energy efficient design.  Jon Biegenzahn will talk about the project development process at Stanford including construction coordination challenges and involving campus stakeholders.


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Low Energy Building: European Design & Control

Clas Jacobson, United Technologies Corporation, Building Control Systems

Monday, May 9, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All


Buildings consume nearly 40% of the world’s energy which is significantly more than either the transportation or industrial sectors. Any comprehensive plan to reduce energy usage and carbon emissions and to enhance energy security must include actions to increase energy efficiency in the building sector. This talk will focus on the current understanding of the options available to reduce energy usage in buildings and will highlight the role of a systems approach and controls in increasing energy efficiency. The delivery process for buildings will be used to highlight where energy is lost in the design, construction and operation of buildings and both current approaches and research opportunities will be highlighted for increasing energy efficiency.

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Emerging Electricity Futures

Amory Lovins, Cofounder, Chairman and Chief Scientist, Rocky Mountain Institute

Monday, May 2, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All

Rocky Mountain Institute’s autumn 2011 Reinventing Fire will explore practical pathways for the U.S. to eliminate oil, coal, and nuclear energy by 2050 (and natural gas thereafter), led by business for profit. This ambitious synthesis integrates transportation, buildings, industry, and electricity—the sole sector previewed in this seminar. Four divergent electricity futures are feasible, plausible, surprisingly similar in cost, but very different in risk. Contrasting their technological, financial, operational, carbon, security, and other risks favors renewable futures—whose variability is manageable with little or no bulk storage—and fair competition by distributed resources in netted islandable microgrids. This future maximizes competitive opportunities for rapid innovation and learning, and seems well matched to global market trends and to emerging revolutions in customer choice and utility business models. All four futures require major regulatory reform. At least the first three need significant new transmission, though probably less for renewables than often supposed. Renewables require big shifts in utility culture and operational procedures—especially if grid architecture becomes more granular—and assume continued progress down observed cost learning curves. Renewables, with scale and technology mix modulated by markets and policies, generally hold promise of more robust response to both political obstacles and exogenous shocks than do nonrenewable futures.

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A Smarter Grid and High Penetration Renewables

Juan de Bedout, Ph.D., Global Technology Director, Electrical Technologies and Systems, GE Global Research

GCEP Distinguished Lecturer

Monday, April 25, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All

The last several years have seen a flurry of activity in industry and academia in the Smart Grid space.  The need for a smarter electrical grid in North America stems from emerging challenges in congestion, reliability, safety and renewable energy integration, that may be more cost effectively resolved with advanced controls technology than with bulk infrastructure growth.  Solutions to these problems require system thinking; many technologies need to work together to collectively provide relief.  It is important to note that the problems change dramatically as you migrate to different parts of the world, with every region having unique challenges and opportunities.  This talk will focus on Smart Grid technologies for mature grids such as the one in North America, and will pay special attention to the integration of renewable energy resources.  A brief discussion of the grid in India will be provided for contrast.

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Analysis and Simulation of Gravity Driven Plumes of CO2

TS Ramakrishnan (Rama), Scientific Advisor at Schlumberger-Doll Research , GCEP Distinguished Lecturer

Monday, April 18, 2011 | 04:15 PM - 05:15 PM | NVIDIA Auditorium, Jen-Hsun Huang Engineering Center | Free and Open to All

We shall introduce the audience to the background behind CO2 accumulation, and infrared absorption for an understanding of global warming. Motivated by the requirement of CO2 sequestration, we shall focus on the theoretical analysis of interface evolution between immiscible fluids within a reservoir structure.

We derive the governing equations for the pressure and interface height to leading order, obtained in the limit of a thin gravity tongue and a moderately dipping bed. In the case of a horizontal bed, the interface shape is governed by a nonlinear parabolic equation that admits a similarity solution only for a specific initial condition. The same is true for a slightly dipping bed, but in a moving coordinate system. We show that for the inclined bed two-dimensional problem, in the reference frame moving with the mean gravity induced advection velocity, the interface motion is dictated by a degenerate parabolic equation, different from those previously published. In this case, the late-time behavior of the gravity tongue can be derived analytically through a formal expansion of both the solution and its two moving boundaries. In three dimensions, using a moving coordinate along the dip direction, we obtain an elliptic-parabolic system of PDEs where the fluid pressure and interface height are the two dependent variables. The solution features are identified for different combinations of dimensionless parameters, showing their respective influence on the shape and motion of the interface.

To conclude the presentation, we show illustrative examples of plume accumulation and migration in complex media, in both two and three dimensions.

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