Champions of Photovoltaics Technology

The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found that certain materials would produce small amounts of electric current when exposed to light. In 1905, Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic technology is based, for which he later won a Nobel prize in physics. The first photovoltaic module was built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity as it was too expensive to gain widespread use. In the 1960s, the space industry began to make the first serious use of the technology to provide power aboard spacecraft. Through the space programs, the technology advanced, its reliability was established, and the cost began to decline. During the energy crisis in the 1970s, photovoltaic technology gained recognition as a source of power for non-space applications.

In this section, we salute a few of the technologists that have made this incredible journey possible, and those who have more recently joined the incredible worldwide effort that is making PV a viable competitor to existing power generating technologies.

To get a better understanding of what today’s top technologists see as the key drivers and challenges in PV today, we asked them to answer take a few questions about the major trends in the photovoltaics/solar power industry today, and key challenges facing the industry not only in terms of technology, but in economics and politics as well.

Charlie Gay, Applied Materials

Charlie Gay was named president of Applied Solar and chairman of the Applied Solar Council at Applied Materials, Inc. in 2009. Gay is also a co-founder of the Greenstar Foundation, an organization that delivers solar power and internet access for health, education and microenterprise projects to small villages in the developing world. Greenstar has been recognized for its innovation by the World Bank, the Stockholm Challenge, the Technology Empowerment Network and the Tech Museum Awards.

Gay began his career in 1975 designing solar power system components for communications satellites at Spectrolab, Inc. and later joined ARCO Solar, where he established the research and development program and led the commercialization of single crystal silicon and thin film technologies. In 1990, Gay became president and chief operating officer of Siemens Solar Industries and from 1994 to 1997, he served as director of the U.S. Department of Energy’s National Renewable Energy Laboratory, the world’s leading laboratory for energy efficiency and renewable energy research and technology. In 1997, Gay served as president and chief executive officer of ASE Americas, Inc., and in 2001 became chairman of the advisory board at SunPower Corporation.

Gay has a doctorate degree in physical chemistry from the University of California, Riverside. He holds numerous patents for solar cell and module construction and is the recipient of the Gold Medal for Achievement from the World Renewable Energy Congress.

We asked Gay to answer take a few questions about what he saw as the major trends in the photovoltaics/solar power industry today, and key challenges facing the industry in terms of technology as well as economics and politics. Here’s what he said:

“As you know, I’ve been in this industry for 35 years, and I’ve seen a lot of promising starts that didn’t amount to much. This time is different: we’ve entered the zone of inflection and LCOE is competitive to gas-firing plants at 15 cents kWh, with more than 50% drop in just the last three years. It’s very, very gratifying to watch this transpire.

“Moving forward, the industry will continue to drive down cost-per-watt, largely through increasing the conversion efficiency and reducing manufacturing costs. As we advance efficiencies, we need to tighten integration of equipment, materials and process. To do this will require greater sophistication and automation for line balancing yield management, materials handling and integrated MES.

“Meanwhile, a lot has been written about China as a producer of PV wafers, cells and modules. It’s a trend we are watching unfold this year, with over 80% of new orders originating in Asia, dominated by China. They are also becoming a leading consumer of solar PV energy as the Chinese government has been active in putting a policy framework in place to emerge as a #1 consumption market.” Gay said.

As far as major technical challenges facing the photovoltaics industry moving forward, Gay said these are primarily associated with the need for higher efficiencies and increased manufacturing productivity.

“Regarding conversion efficiencies, most roadmaps are being implemented on a continuum of technical improvements. Today, using screen printing technology, innovative double printing techniques are making contact lines ever finer, minimizing the amount of light blocked from getting into the solar cell. We’ve also entered the stage of expanding the use of selective emitters, some of which are facilitated by screen printing and by new materials for forming the junction.

“We’re also seeing the back of the cell receive more attention for various kinds of back contact configurations where more reflective metallization is possible through simplified back etching of cells, and the high reflectance properties of using aluminum.

“As we strive to improve efficiency, another area being looked at is minimizing surface recombination. Surface recombination of course happens on the front and the back of the solar cell, and we’re developing unique solutions that allow optimal processing for both front and to back properties where the different conductivity types require different film properties.

“Beyond process, there is also a movement toward improving factory automation for better metrology and inspection -- and the capability to make and handle thinner wafers, which helps bring down the direct cost of materials in the use of silicon.

“This next generation of PV solar is really a solutions game that far more complex than just tool making. And it’s precisely why I joined Applied Materials. Applied has the unique perspective and experience to deliver precisely these kind of manufacturing solutions to market, having successfully done the same for both the semiconductor and display industries.

“Now it’s solar’s turn to move from boutique to mainstream. I remember when it took the industry a week to manufacture a single megawatt. Today the industry can crank out a megawatt in 30 minutes,” he said.

What are the major economic/policy/regulation challenges facing the photovoltaics industry moving forward? Gay said a number of specially crafted policies and incentives are needed to create a more robust foundation for growth. “For example, strong government support for renewables in Germany and China has turned these countries into global leaders in this market. However, despite the economic and global policy challenges and uneven progress worldwide in 2009, the market for solar PV grew 60% year-over-year and the outlook for 2010 remains positive. We’re expecting a range of 30-50GW of new manufacturing capacity to be added over the next three years. So we believe that the solar market is still very dynamic and poised to grow,” Gay said.

Daniel M. Kammen, U of California, Berkeley

Daniel M. Kammen is the Distinguished Professor of Energy at the University of California, Berkeley, where he holds appointments in the Energy and Resources Group, the Goldman School of Public Policy, and the department of Nuclear Engineering. Kammen is the founding director of the Renewable and Appropriate Energy Laboratory (RAEL) and the co-Director of the Berkeley Institute of the Environment. In April 2010 Kammen was named by Secretary of State Hilary R. Clinton to be the first Clean Energy Envoy to the Americas.

Kammen received his undergraduate (Cornell A., B. ’84) and graduate (Harvard M. A. ’86, Ph.D. ’88) training is in physics. After postdoctoral work at Caltech and Harvard, Kammen was professor and Chair of the Science, Technology and Environmental Policy at Princeton University in the Woodrow Wilson School of Public and International Affairs from 1993 to 1998.

He then moved to the University of California, Berkeley. Kammen directs research programs on energy supply, transmission, the smart grid and low-carbon energy systems, on the life-cycle impacts of transportation options including electrified vehicles and land-use planning, and on energy for community development in Africa, Asia, and in Latin America. Daniel Kammen is a coordinating lead author for the Intergovernmental Panel on Climate Change (IPCC), which won the Nobel Peace Prize in 2007. Kammen is the co-developer of the Property Assessed Clean Energy (PACE) Financing Model: energy efficiency and solar energy financing plan that permit installation of clean energy systems on residences with no up-front costs. PACE was named by Scientific American as the #1 World Changing Idea of 2009 (co developer with Cisco’s DeVries). Kammen serves on the National Technical Advisory Board of the U. S. Environmental Protection Agency. He hosted the Discovery Channel series ‘Ecopolis, and had appeared on Frontline, NOVA, and twice on ’60 Minutes’. Kammen is the author of over 220 journal publications, 4 books, 30 technical reports, and has testified in front of state and the US House and Senate over 30 times.

Kamen said he’s very excited two trends in the photovoltaics/solar power industry today. “One is the steady push for $/watt parity with fossil fuels, through cost/watt innovations, building integrated cells, and markets that reward peak demand coincidence. The incredible wave of technical innovations in conventional cells, thin-film, and nano-solar technologies make this a very hopeful path,” he said. “The second is a broader push to rationalize energy markets so that rates reflect both externalities (e.g. the REGGI carbon market, and California's soon-to-be-launched one) and actual supply and demand -- real-time pricing -- and both are vital innovations that reward clean energy, and in many ways solar in particular.”

Kammen said the biggest technical challenge facing the industry is low $/watt, not necessarily highest efficiency. “Thin film solar, and nano-solar both show incredible potential, and what is really needed are the sustained research support -- both from the public and private sectors -- to bring these to market,” he explained.

The major economic/policy/regulation challenges facing the photovoltaics industry moving forward? “Clearly we have to overcome the up-front cost barrier, which is why I've been working so hard on PACE financing (see http://rael.berkeley.edu/financing) as this make the up front funds available to break the cost/lifetime logjam
that keeps solar out of everyday energy and construction markets,” Kammen said. “ALL new homes come with a solar option, built into the overall cost.”