POWER October 2020 - 21

TOP PLANT
that required careful integration, DTE
completed the full project scope between
May 2018 and December 2019-
on schedule and on budget, she said.
The integrated project includes:
Two 14.5-MW Solar Turbine Titan
1. DTE Energy's 34-MWe Dearborn Central
Energy Plant at Ford's Dearborn Research and
Engineering Center integrates a 15,800-ton
central chilled water plant with four 3,200-ton
chillers, one 1,200-ton heat pump chiller, and
one 1,800-ton heat pump chiller each with R1233zd
refrigerant. The facility also includes a
5.3-million-gallon chilled water energy storage
tank, which is designed to help the 900-acre
campus minimize on-peak electrical demand.
Courtesy: DTE Energy/OPN Architects
was selected following Ford's May 2016
request for proposals, helped the company
hash out a number of scenarios
that would best fit Ford's value proposition,
said DTE Business Development
Director Michael Larson. Eventually, in
February 2017, Ford and the DTE entities
settled on a design-build-own-operatemaintain
(DBOOM) contract with DTE
Energy Services, a complex mechanism
that enabled the project's collaborative
delivery. It allowed Ford to assign expertise,
ownership, and performance incentives
to the party it deemed best-suited
to address them to reap the best efficiency
and sustainability benefits.
Meanwhile, it allowed DTE to integrate
its specialized knowledge and efficiently
streamline operability of the generation,
grid, and thermal network to make the
most of the front-of-the-meter case. Under
the definitive agreements executed
in October 2017, DTE Power & Industrial
would build, operate, and maintain the
integrated facility for 30 years; DTE Gas
would fuel it; DTE Electric would own the
CHP plant; and DTE's Power & Industrial
group would own the heating and chilling
plant, while Ford would have the option
to take over operations at the conclusion
of the term.
A Collaborative Technology
Solution
Construction of the project required
as much significant effort and coordination,
noted Mary McVeigh, DTE Engineering
Manager. Because the CEP
was sited in the middle of the active
REC campus (Figure 1), construction
activities needed to be planned carefully
to minimize disruptions. However,
despite the broad technology solution
October 2020 | POWER
130 Gas Turbines. McVeigh also noted
DTE opted to " upsize " the project capacity
from the originally envisioned Mars
100 11.4-MW gas turbines to best utilize
the indoor plant's footprint and leverage
economics of scale.
Rentech Heat Recovery Steam Generators
(HRSGs). The HRSGs, which are
equipped with supplemental firing, are
attached to each turbine but can be bypassed.
When fully fired, the HRSGs can
boost steam output from 70,000 pounds/
hour in turbine exhaust gas mode to approximately
180,000 pounds/hour.
A 5-MW Siemens Steam Turbine.
The steam turbine has " significant turndown
capability to allow for utilization
of excess steam, " said Humphries. The
condenser cooling loop is also designed
for 100F inlet cooling water, which in turn
generates hot water for distribution to
campus, he said.
The Chilled Water Plant. The central
chilled water plant integrates four 3,200ton
duplex Trane chillers. Two additional
chillers, nominally 1,200 ton and 1,800 ton,
are heat pumps that can draw on energy
and distribute hot water and chilled water
through two different means. Humphries
explained: " One, through exchanging Btus
between the chilled water and hot water
systems, which is referred to as 'simultaneous
heating/cooling mode,' and the
other is through integrating a potential future
geothermal field. " The plant, notably, is
also outfitted with steam-to-hot-water heat
exchangers, as well as geothermal-ready
piping connections for 3,000-ton vertical
geothermal heat exchangers.
The plant is capable of distributing
38,500 gallons per minute (gpm) of
chilled water at 42F at 70 psig and 19,500
gpm of 120F water at 85 psig to campus
through supply and return pipes. Also
notable is that the chillers use R-1233zd
refrigerant, which is a fairly new technology
to the U.S., noted Humphries. " It
essentially has a global warming potential
equivalent to carbon dioxide, versus
some of the common refrigerants, which
are on the 50 to 1,500 times scale, " he
said, noting that aspect was one of many
reasons the plant is seeking Leadership
in Energy and Environmental Design
(LEED) Gold certification.
The Thermal Storage Tank. The
chilled water piping system is connected
www.powermag.com
POWER POINTS
Winning Attributes
✔ Designing, building, and operating a
highly efficient and flexible facility
that serves multiple functions,
including to provide power, steam,
and hot and chilled water.
✔ Integrating heating and chilling
facilities, geothermal-ready
infrastructure, and an electricity
peak-shaving thermal energy
storage tank to boost efficiency and
meet sustainability objectives.
✔ Collaborating with Ford and multiple
engineering groups to identify the
best project value proposition.
✔ Innovating a project development
model that can be applied to
other sustainable infrastructure
undertakings.
to a 5.3-million-gallon thermal energy
storage tank, which supplies chilled water
as needed to help the campus shave
peak demand. The storage tank is designed
to supply 5,000 tons of chilled
water for 8 hours, between midmorning
and early evening.
Smooth, Digitally Enhanced
Operations
Asked how the plant has operated to date,
Kevin Siess, DTE Energy plant manager,
told POWER that despite the many novel
component integrations, it is " extremely
stable. " Though CEP experienced a handful
of trips in the first week, it has continued
to run 24 hours a day, monitored by an
operating staff of only six people. The lean
staff's operations and maintenance efforts
are boosted by digital twin technology in
use at the plant that was developed and
customized by Michigan startup Vital Tech
Services, Siess noted. Paired with information
from 3D modeling used to build the
plant, virtual representations of the facility
and its critical equipment have been crucial
to providing monitoring and planning.
" We never stopped running throughout
the pandemic, even when down to a
skeleton crew, and we're trading off two
guys on [12-hour shifts] for seven days
straight, and switching to a different pair
of people to minimize contact and overlap, "
he said. " It was a bit stressful, but
the team did extremely well. " ■
-Sonal Patel is a POWER senior
associate editor.
21
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POWER October 2020

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