I found Nelson Marans' letter "Chemistry not so appealing," which details the obstacles facing potential chemists, to be very disheartening (C&EN, June 6, page 3). Even after being in the pharmaceutical industry for several years, we are still compelled by senior management to further our education in order to qualify for better positions. Having an A.A.S. in chemical technology has proven to be quite beneficial to me, as I yet remain several courses shy of a B.S. degree. I can't imagine the challenge that I would probably face if I had to move to another company, even though I have a very solid background. I can only hope that Marans is more wrong than right, so that many aspiring chemists can experience a bright future in a changing industry.
Sunny days ahead?
In "Expanding Solar Energy Globally," Mitch Jacoby summarizes a recent workshop by the Department of Energy to "identify basic research priorities" to "revitalize and redefine a solar energy research program" (C&EN, May 30, page 35).
In 1973 at the Mitre Corporation (a federally funded R&D center, now Mitretek Systems Inc.), I received a call from the National Science Foundation asking me to conduct a study under the recently authorized "Research Aimed at National Needs" program. The study was to develop a research program to foster the use of solar energy. My report, "Energy Use and Climate," NSF-RA-N-75-052, was published in April 1975 (NSF Contract # C-938).
This was the first U.S. government report stating that "the use of solar energy instead of 'stored' energy sources (both fossil and nuclear) would avoid the problem of ... global temperature increase." I included forecasts of world energy use from 1975 to 2100 and the consequent possible atmospheric temperature rise globally and at the poles. My conclusion was that the use of fossil fuels would have to be sharply curtailed by 2025 and eliminated by 2100 to avoid temperature increases of 2 to 3 °C globally and 10 °C at the poles. The world is rapidly moving toward those numbers, as has been amply observed. I was interested to read in the article that Nathan S. Lewis said at the DOE workshop that "to maintain CO2 levels at 350 ppm (about 25 ppm lower than today's value), all carbon-emitting energy sources would need to be abolished within 45 years."
I was amazed and saddened to read that the research priorities discussed in the article by panels focused on solar electric, solar fuels, and cross-cutting issues, which had been identified since 1975 by NSF and later by DOE and have been actively pursued ever since. Despite the billions of dollars invested, we have essentially lost 30 years in implementation of significant amounts of solar energy production. Solar electric and solar fuels are still too expensive relative to fossil fuels except for isolated applications. Unless we wait until global warming is fully apparent to everyone on Earth, the only way to make solar energy cost-effective is to legislate a carbon tax or other method to sharply curtail the use of fossil fuels.
Richard S. Greeley
St. Davids, Pa.
I am currently employed by a major global photovoltaic (PV) manufacturer and would like to make a few comments on some of the statistics cited in Jacoby's article. PV power is currently only two to three times the cost of coal or other conventionally generated electricity when you factor in transmission and distribution charges and not just the generation charge. Current PV costs include all three components, since it is generated at point of use.
PV will never be an applicable transportation fuel, except in the remote future when PV may be used to generate hydrogen via electrolysis, which is an inefficient use of electric potential. Coal gasification and liquefaction will be needed for our various transportation fuels until we can generate a new renewable source of power-dense portable fuel, and therefore they should not be burned to produce electricity in the interim.
Novel materials, while they create new ideas and help us understand physics and chemistry in new ways, will not be applicable to solar power in the near term, because all organics and nanomaterials are subject to degradation when exposed to 1 kW per m2 and 60 °C operating conditions, as well as ultraviolet, oxygen, and humidity factors. Biological systems for sunlight capture have the benefit of internal mechanisms of regeneration and protection to survive in full-sun conditions. Those systems that can continuously generate energy in full sun for 25 years are significantly more limited, a time period that is the standard warranty for PV modules produced today.
Most of today's photovoltaic cells are not produced on indium tin oxide at all; in fact, less than 10% use transparent conducting oxides. Crystalline silicon is the material of choice, known for its stability, predictable behavior, and large abundance.
It is a good time to take on the solar energy challenge. Ten percent of what Congress initially approved for the war in Iraq would have doubled the world sales of PV last year (nearly $8 billion) and would have offset the equivalent electricity of installing two more commercial-scale power plants.