District Energy - 2011 3rd Quarter

also helps reduce peaks on the grid during
the hottest times of the day. In addition, TES
enhances reliability, since it can be brought
into service quickly and uses approximately
10 percent of the equivalent emergency
power it would take to operate a chiller.
Chilled water leaves the tank at
42 degrees F and enters the distribution
system through a 60-inch pipe. After it
has been used in the buildings for cooling,
the water travels back through the dis-
tribution system, returning to the tank at
approximately 58 F. At night, electric cen-
trifugal chillers cool the returned water
back to 42 F for the next day’s use.
For these reasons, the new TES tank
was one of the first projects TECO com-
pleted. To facilitate cost-effective use of the
available land, the tank was designed at
150-ft high, which makes it the tallest TES
tank in the world.
Courtesy Burns & McDonnell.
Inside TECO’s Operations Support Facility, the state-of-the-art control room allows the district energy plant
operator to better manage the integrated utility systems serving the world’s largest medical center.
operations. The space is hardened to ensure
structural and operational integrity are main-
tained during severe weather conditions.
Operations Support Facility
TECO’s growth resulted in a need to
provide environmentally controlled space
to warehouse sensitive parts and materials,
space for training operators and mainte-
nance personnel, and secure areas for plant
operations. To address these needs, TECO
added 29,000 sq ft of new building space
to its existing Operations Support Facility.
The addition includes a new state-of-the-
art control room that features 24 flat-screen
monitors where staff can track system per-
formance and site security and oversee daily
CHP System
Wanting to generate thermal energy
as efficiently as possible, TECO added
CHP to help squeeze maximum energy
from every British thermal unit of fuel con-
sumed. The technology has provided the
additional benefit of improved reliability
and significantly reduces emissions to the
environment.
In a traditional central power delivery
system, only about one-third of every Btu
of fuel consumed is converted into electri-
cal energy; the remaining two-thirds go
up a stack and are wasted. TECO’s 48 MW
CHP plant, by comparison, operates at
approximately 80 percent efficiency – more
than 50 percent improvement over a cen-
tral utility plant fed from the grid – and
with a combined heat rate between 5,500
and 6,700 Btu/k Wh.

Due to campus growth, Burns & McDonnell built a permanent bridge over Brays Bayou to extend utilities to institutions that are expanding on Texas Medical
Center’s mid and south campuses.
14 District Energy / Third Quarter 2011
© 2011 International District Energy Association. ALL RIGHTS RESERVED.
Courtesy Thermal Energy Corp. Photo Paul Howell.