Completed Projects: Technical Research

Evaluating the Solar Energy Potential of the Department of Defense
The GW Solar Institute has focused on developing an objective and systematic approach to determining the solar energy potential of large organizations. One key focus area of this effort was developing a multi-criteria decision model for solar implementation on Defense Department bases in the US. The results across the 200 sampled US military bases identified 34.2 million MWh per year of fossil energy consumption and 28.5 million metric tons per year of CO2 emissions that could be offset by solar energy technologies at a cost of $82.2 billion, requiring only 0.82% of the total land area of the sampled bases. These results were published in the Fall 2011 issue of Environmental Practice, the quarterly journal of the National Association of Environmental Professionals. The lead author, Ariel Castillo, also provided important technical guidance in the development of the “Department of Defense Energy Security Act” (DoDESA), which was introduced in the 111th Congress and later reintroduced in the 112th Congress.

Large-Scale Solar Deployment Models
Institute-funded research in the School of Engineering and Applied Sciences, conducted by doctoral student Steve Burns and his co-investigator, Professor Jonathan Deason, resulted in the development of a linear optimization model to evaluate multiple electricity transmission scenarios associated with transitioning the nation to a renewable energy based electric power generating grid. The research, presented at the Solar Symposium in 2009 and 2012, identifies key pathways and obstacles for the United States should it look to power the electric grid primarily with solar. Importantly, the research uncovered that significant cost-savings could be achieved for ratepayers by avoiding regional transmission upgrades and focusing on reducing regulatory obstacles that would needlessly delay development of major cross-country transmission lines.

Analyzing the Cost and Performance of Photovoltaic Technologies
One of the Institute’s most important research efforts involved the drafting and the coordination of peer review of a major chapter of the DOE’s SunShot Vision Study. The SunShot Vision Study represented a major effort by the DOE to develop a far more aggressive deployment approach for solar energy to serve U.S. electricity needs. A key study chapter entitled “Photovoltaics: Technologies, Cost, and Performance,” relied on the Institute’s studies of the interplay between improved module efficiency and balance of system costs to highlight the productive future R&D directions for PV technologies. This work was conducted under a subcontract to the National Renewable Energy Laboratory.

Defining the Impact of Tellurium Supply on Cadmium Telluride Photovoltaics
Another significant research project involved an analysis of how potential reductions in the thickness of the cadmium telluride (CdTe) layer in thin film solar modules and enhanced tellurium (Te) recovery could substantially boost the projected manufacturing potential of CdTe solar modules. This research was stimulated by the needs of the DOE SunShot Vision and was published in the May 7, 2010 issue of Science magazine.

Improving Assessment of the Air Emissions Reduction Benefits of Solar Energy
In the spring of 2010, the GW Solar Institute’s former Co-Director, Debra Jacobson, published an article on potential of solar energy to reduce air pollution in the inaugural edition of The George Washington University Journal of Energy and Environmental Law, which was subsequently republished in the Yale School of Forestry and Environmental Studies in a report of the work of the REIL Project, a leading international renewable energy network. The article, which was co-authored with Colin High of Resources Systems Group, was titled “U.S. Policy Action Necessary to Assure Accurate Assessment of the Air Emissions Reduction Benefits of Increased Use of Energy Efficiency and Renewable Energy Technology.” The publication analyzes three common methodologies used by states and Federal agencies to quantify air emission reductions from increased use of energy efficiency and renewable energy technologies, including solar photovoltaics. The law review article finds that the major emissions reductions calculator, eGRID, understates the carbon dioxide and nitrogen oxide emission reduction benefits of PV in two regional power markets by approximately 65% to 165%. The research results were provided to the Climate Registry, the U.S. Environmental Protection Agency, and the DOE to underscore these serious issues. In addition, the co-authors provided the article to the White House Council of Environmental Quality to assist in the development of a GHG reporting protocol for Federal agencies.

Researching Improved Processes for Hydrogen Conversion
In 2010, Professor Stuart Licht of the GW Department of Chemistry completed research funded by the Solar Institute that explored the economics of a novel hybrid method for the centralized production of hydrogen gas. This method, called Solar Thermal Electrochemical Photo (STEP), uses concentrating PV electricity and solar thermal energy to substantially reduce the cost of generating hydrogen gas to a cost equivalent to that of gasoline at $2.60 per gallon. An article describing the foundation for this work was published in the Journal of Physical Chemistry,and the results of this research were published in the International Journal of Hydrogen Energy and a publication detailing advances in this research was published in the Journal of Physical Chemistry Letters.

Refining the Solar Grand Plan
In 2008 and 2009, the Institute’s Director authored and co-authored several papers that expanded on the Solar Grand Plan that was first publicized by former Institute Director Ken Zweibel and two co-authors in a groundbreaking article in Scientific American in January 2008. These recent papers elaborated on the details of the Grand Plan with respect to the engineering and economics of the interconnected system of storage and transmission that would support the distribution of low-cost solar electricity from the Southwest to other regions of the country. This analysis was published in Sun and Wind EnergyEnergy Policy, Progress in Photovoltaics: Research and Applications, and presented at the annual IEEE PV Specialists Conference – a meeting of the world’s leading PV professionals. The IEEE meeting was especially valuable because it provided the Institute with a means of updating key PV technology experts about the global impact of solar.