| Cogeneration
Project
Thinking Inside the Box in Wisconsin
by
Elaine Schmidt There's no way to fit a behemoth of a power cogeneration
plant into a newly constructed building.
|
And so you put the equipment in place and build the enclosing structure
around it, which is the approach taken on the $180 million West Campus Cogeneration
Facility under construction on the University of Wisconsin campus in Madison.
"If
you build an office building, you build the shell and then bring the furniture
in," said Don Peterson, project manager for Madison Gas and Electric. "But
we couldn't do that here."
Crews began driving piles and pouring foundations
in fall 2003 for the system of piles and pile caps connected by concrete grade
beams that the facility sits on. The power generation equipment was set in place
during winter 2004, and the plant is expected to be commercial in mid to late
spring.
The process of setting equipment in place and building around it
is not as simple as it sounds, given the size and weight of the power-generation
equipment. With just one of the steam turbines weighing at 242,000 lbs., the equipment
required special handling.
The large pieces of generating equipment were
brought into downtown Madison via rail and loaded onto 120-ft.-long heavy-haul
trucks. To avoid traffic and pedestrian snarls, the trucks were escorted to the
site by police during overnight hours while the student population was on Christmas
break.
A 300-ton crane was used to lift the equipment into place.
And
because of the extreme weight loads, a temporary bridge had to be installed over
the existing Willow Creek Bridge on the Observatory Drive delivery route.
Has
Joint Ownership The cogeneration facility, which is jointly owned by MGE
and the state of Wisconsin, will have a capacity of 150 MW of electricity, 20,000
tons of chilled water and 500,000 lb./hr. of steam. It will provide heating and
cooling for the university campus and electricity for customers of MGE.
Cogeneration
is the simultaneous production of electricity and thermal energy.
The
residual thermal energy generated in the process of producing electrical energy,
which is wasted in most electrical generation facilities, is used in the production
of steam heat.
"This is not really an unusual project, although it
is unusual for Wisconsin," Peterson said. "There are some of these plants
in other parts of the country."
He added that rising energy prices
have increased interest in cogeneration.
Despite campus conservation measures
that have saved enough electricity to power 2,500 homes and ongoing MGE programs
to help customers reduce electric usage, Madison's population and business growth
and a societal growth in technology use are creating increased power demand. In
addition, new classroom and research structures on the campus are adding to the
burden.
Overcoming Logistical Nightmares Putting
a plant in the middle of such a high-use area required careful logistical planning
and sensitive design considerations.
"Normally a plant like this would
be built out on a site away from a town or city and have no enclosure around it,"
said Jim Moravec of Potter Lawson Inc. of Madison, the plant's design consultant.
He said that the units are normally intended to be freestanding, but the Madison
enclosure was needed to allay concerns about noise from the plant disrupting the
neighborhood as well as aesthetic concerns about the plant's visual impact.
There
was one other problem: Building in the middle of downtown Madison meant there
was no rural-site luxury of space. The plant sits on a 4.5-acre site.
"Probably
one of the most challenging parts of the project is that we don't have any sizable
laydown area," Peterson said. "So we have had to take just-in-time delivery
on everything. In addition we have had the logistics of getting parts not only
from Wisconsin but also from Austria, France, Texas, New York, Minnesota - basically
from all over the world - and getting them there at the right time.
"We
have to make sure nothing comes in a day or two early - or we have to store it
- or a day or two late - or we have 300 guys standing around with nothing to do." Making
It Fit The size of the facility, in proportion to the small
site and neighboring structures and streets, was a big design issue. The building's
height varies from spot to spot, with the cooling towers reaching to 117 ft.,
or about 12 stories.
It is located at Walnut Street and Herrick Drive,
beside the Walnut Street Heating Plant and across from several university greenhouses.
"We
worked with the engineers to create a palate of materials to break down the mass
of the building and create a more friendly scale," Moravec said. "We
had little flexibility in the size of the components of the facility, which were
set by engineering constraints."
He said placement of the components
on the site was determined by the shadows the components would cast.
"We
did extensive, three-dimensional shadow studies for different times of the day
and times of the year to determine the impact on the greenhouses across the street,"
he said. In the end, the shadow studies may have been unnecessary because the
university has decided to build new greenhouses outside the shadow-impacted areas.
Moravec
added that in addition to working with the project engineers, his firm worked
with the university's architects and landscape groups to create a workable structure.
"The
outside of the building is all precast ribbed panels or thin-set brick set into
precast," Moravec said. The choice of thin-set brick was dictated by a combination
of economics, no laydown space and the difficulty of erecting scaffolding on the
site for traditional brickwork.
But the biggest task is installing the
enormous amount of piping required for a plant. In all, the project has 94,608
lin. ft. of piping, some of it up 72 in. in diameter. That translates into almost
18 mi. of piping.
Conservation efforts on the project were not limited
to the end goal of creating a high-efficiency energy plant. With the help of WasteCap
Wisconsin, 717,000 lbs. of metal and 288,000 lbs. of concrete have been recycled
from the site. Some of the refuse came from a pre-existing foundation onsite and
some from the routine cleaning of concrete trucks.
| 
print this page
e-mail this page
