December 2004 - Materials Science Institute - University of Oregon

SA 50
(business leader of the year)
Peter Cartwright
Chair and CEO
Calpine Corporation, San Jose, Calif.
Committed his company to energy sources that reduce carbon emissions.
In May, Peter Cartwright announced that his company, the
electric utility Calpine, would invest only in plants that emit
no more carbon per unit of generated electricity than is characteristic
of plants fi red with natural gas, the low-carbon fossil
fuel par excellence. Calpine’s policy requires it to reduce future
plants’ carbon dioxide emissions to 850 pounds per megawatthour,
down from its already record-low level of about 900
pounds. The average fossil-fuel plant in the U.S. emits about
1,900 pounds.
The company’s commitment sets a precedent not only for other
utilities but also for policymakers. The Bush administration
has favored the development of coal-fi red plants, which produce
much more carbon per watt than other energy sources.
Cartwright, 74, was trained as an engineer and worked in the
energy industry for some 30 years before founding Calpine in
1984 with $1 million in seed money. Since then, he has built it
into a leading energy fi rm, with 3,000 employees and 22,000
megawatts of generating capacity. In the process, it has earned
one of the best environmental records in the business, in part
through a reliance on natural gas and geothermal steam, in
which it has a bigger stake than any other company. In recent
years, it has carried out a $187-million project to use treated
wastewater to recharge the gradually diminishing reservoirs of
geysers feeding its plant near San Francisco, making it apparently
the largest geothermal generating plant in the world.
Calpine wrings every last erg of energy from gas by combining
several cycles of generation. Gas burns in a turbine that drives
a generator; exhaust gases then heat water into steam, which
drives a second turbine and generator; remaining heat is then
vented in cooling towers. The company has even investigated
salvaging something from that waste heat, by using the carbonrich
exhaust to warm and fertilize greenhouses. Cartwright recommends
that the U.S. replace many coal-fi red plants and all
single-cycle gas-fi red plants with the combined-cycle system.
Calpine has garnered one of the best environmental records
in the electric-utility business through a program that relies
CORPORATION
on geothermal steam and natural gas; the latter is used to
power a plant in Edinburg, Tex. (above). CALPINE
52 SCIENTIFIC AMERICAN DECEMBER 2004
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