Engineers Will Demonstrate New System To Prevent Power Failures, Purdue News/Science Daily 
Abstract: A team of engineers led by a Purdue
University researcher will demonstrate a new system in April that
aims to avert power failures by automatically adapting to the
daily fluctuations in electricity consumption.
The system might be especially helpful in easing problems
associated with electricity shortages and utility deregulation. It
would precisely predict and monitor electricity consumption for
each customer from one hour to the next, also making it possible
to charge higher rates for those placing the greatest strain on
the power grid during times of peak demand.(…)
"When there is a shortage of electricity and one customer
wants to heat up his Jacuzzi, he should be paying more," Tsoukalas
said. "An essential element of our approach is to modify the
behavior of customers for the well-being of the entire
system."
Work on the new system, called TELOS, for Transmission
Entities with Learning Capabilities and On-Line Self-Healing, is
headed by Tsoukalas. He is one of 23 researchers in the Consortium
for the Intelligent Management of the Electric Power Grid.
TELOS is said to be a "self-healing" system because it
automatically adjusts to new conditions. It is designed to prevent
power failures by anticipating the quickly changing demands of
industrial, commercial and residential electric customers. The
system would accurately predict power needs for the coming day and
then automatically meet those demands by better managing
electricity distribution and supplementing the grid with power
from small natural gas or diesel generators, which would kick on
when needed. (…)
Members of the consortium include engineers and graduate
students from Purdue University; Commonwealth Edison Co., a
utility serving northern Illinois; the University of Tennessee;
Fisk University; the Tennessee Valley Authority, the nation's
largest public power company; and the Electric Power Research
Institute, an organization of electric utilities.(…)
Fuzzy logic systems work by evaluating the overall accuracy,
instead of the fine precision, of a solution to a problem. The
human brain uses the same sort of approach to make effective
decisions.(…)
In a similar way, mathematical models can be used to predict
future changes in electricity demands by evaluating the present
usage in the context of environmental factors and historical
patterns. Such a system might reason along the following lines:
"The weather is getting warmer, it's the middle of summer and the
humidity is increasing. Therefore, when historical consumption
patterns are considered, we should expect the demand to rise by so
much in the next hour."
Utility company workers currently perform the prediction
role. They begin the day by trying to anticipate what the power
demand will be over the next several hours in the entire grid.
However, different parts of the service area sometimes have their
own distinctive microclimates that affect electricity use.
Therefore, engineers are aiming to break the service area into
LAGs.
TELOS is scheduled to be completed by the end of 2001 and to
be operating in 2003 on a trial basis in the Commonwealth Edison
and Tennessee Valley Authority service areas. If it works, TELOS
will be available for use on a national level, Tsoukalas
said.
Heat Vent" In Pacific Cloud Cover Could Diminish Greenhouse Warming, NASA/Science Daily
Abstract: The tropical Pacific Ocean may be able to
open a "vent" in its heat-trapping cirrus cloud cover and release
enough energy into space to significantly diminish the projected
climate warming caused by a buildup of greenhouse gases in the
atmosphere.
If confirmed by further research, this newly discovered
effect - which is not seen in current climate prediction models -
could significantly reduce estimates of future climate warming.
Scientists from NASA's Goddard Space Flight Center in Greenbelt,
Md., and the Massachusetts Institute of Technology present their
findings in the March 2001 issue of the Bulletin of the American
Meteorological Society.
"High clouds over the western tropical Pacific Ocean seem to
systematically decrease when sea surface temperatures are higher,"
says Arthur Y. Hou of Goddard's Data Assimilation Office. Hou and
co-authors Ming-Dah Chou of Goddard's Climate and Radiation Branch
and Richard S. Lindzen of MIT analyzed satellite observations over
the vast ocean region, which stretches from Australia and Japan
nearly to the Hawaiian Islands. (…)
The study compares detailed daily observations of cloud
cover from Japan's GMS-5 Geostationary Meteorological Satellite
with sea surface temperature data from the U. S. National Weather
Service's National Centers for Environmental Prediction over a
20-month period (January 1998 to August 1999). The researchers
found that cumulus cloud towers produced less cirrus clouds when
they moved over warmer ocean regions. For each degree Celsius rise
in ocean surface temperature, the ratio of cirrus cloud area to
cumulus cloud area over the ocean dropped 17-27 percent. The
observed range of surface temperatures beneath the clouds varied
by 6.3 degrees Fahrenheit (3.5 degees C).
The authors propose that higher ocean surface temperatures
directly cause the decline in cirrus clouds by changing the
dynamics of cloud formation and rainfall. Cirrus clouds -
high-altitude clouds of ice crystals - typically form as a
byproduct of the life cycle of cumulus towers created by rising
updrafts of heated, moist air. As these cumulus convective clouds
grow taller, cloud water droplets collide and combine into
raindrops and fall out of the cloud or continue to rise until they
freeze into ice crystals and form cirrus clouds.
"With warmer sea surface temperatures beneath the cloud, the
coalescence process that produces precipitation becomes more
efficient," explains Lindzen. "More of the cloud droplets form
raindrops and fewer are left in the cloud to form ice crystals. As
a result, the area of cirrus cloud is reduced."
Clouds play a critical and complicated role in regulating
the temperature of the Earth. Thick, bright, watery clouds like
cumulus shield the atmosphere from incoming solar radiation by
reflecting much of it back into space. Thin, icy cirrus clouds are
poor sunshields but very efficient insulators that trap energy
rising from the Earth's warmed surface. A decrease in cirrus cloud
area would have a cooling effect by allowing more heat energy, or
infrared radiation, to leave the planet.
If this "iris effect" is found to be a general process
active in tropical oceans around the world, the Earth may be much
less sensitive to the warming effects of such influences as rising
greenhouse gas concentrations in the atmosphere. The researchers
estimate that this effect could cut by two-thirds the projected
increase in global temperatures initiated by a doubling of carbon
dioxide in the atmosphere.
