The University Campus as a Living Laboratory for Sustainability:
Application of Smart Integrated Membrane Systems Technology
for Treatment and Recycling of Cooling Tower Water at the UCLA Cogeneration Plant
Nurit Katz, Chief Sustainability Officer
Steve Olsen, Chief Financial Officer and Vice Chancellor, Finance, Budget and Capital Programs
Lewis Rosman, Director
of Energy Services at
UCLA Facilities
Management and
Professor Yoram Cohen,
look over the cooling
towers at the UCLA
Cogeneration Plant
UCLA Cogeneration Plant
The UCLA Cogeneration Plant is a 44MW natural gas fired
plant that utilizes the waste heat from electrical power
generation to generate steam and chilled water for the
campus. The plant provides approximately 70% of the
electricity and almost all the heating and cooling for the
campus. Roughly 5% of the gas used at the plant is biogas
from a local landfill. The power provided from the plant
results in approximately half the greenhouse gas
emissions of power from the local utility.
Water Action Plan
The Cogen cooling tower water filtration project is one of
five key projects in UCLA’s Water Action Plan, a plan to
reduce per capita potable water consumption 20% by
2020. The other four initiatives and their respective
water savings are:
• Artificial turf on the intramural field:
6.4 million gallons per year
• Satellite Wastewater Treatment Plant (in feasibility
study):
144 million gallons per year
• Housing Fixxture Replacements:
4.3 million gallons per year
• Tiverton Greywater Pilot:
190,000 gallons per year
Professors Yoram
Cohen and Panagiotis
Christofides and their
team of grad students
with the groundbreaking Com2RO
system, a smart
water-cleaning
system.
Introduction
UCLA is a living laboratory for sustainability. The physical campus operations
provide a demonstration ground for new clean technologies, and research,
education, and operations are integrated in innovative ways. The UCLA
Cogeneration Plant cooling towers require around 60,000 to 100,000 gallons of
water loss daily in order to control mineral scaling and salinity. In 2011, UCLA
Facilities Management partnered with the UCLA Water Technology Research
Center to pilot a UCLA developed smart water filtration system to treat the
blow down water and recycle it. The pilot was successful and now the
technology will be permanently installed through a commercial installation
resulting in significant water conservation and savings for the University.
Economic Analysis
Assumptions
Feed water capacity:
135 gpm
Water recovery rate:
75%
City water cost:
10.72/kgal ($8.02/HCF)
Estimated water savings: 17.3 million gallons/year
Estimated savings from retiring prior RO system service contract:
$48,000/yr (starting in year 2)
Estimate average annual electricity cost: $15,272
Technology
The mission of the Water Technology Research Center (WaTeR)
is to advance technologies of water production in order to
develop new and economical alternative sources of potable,
irrigation, and consumptive water uses. The Com2RO can handle
the Cogen’s blowdown water because of the combination of
ultra filtration and reverse osmosis designed primarily for
removing dissolved salts- water passes through the reverse
osmosis while the dissolved salt ions are repelled — but the RO
membranes would choke on larger particles. Ultra filtration
steps in ahead of the osmosis to remove micro-organisms and
other particles larger than salts. The system is smart in that it
can shift for different kinds of water and be controlled remotely.
Estimated Savings
Year 1
Year 2
Year 3
Year 4
Year 5
Expenditure
-$70,039
-$70,039
-$70,039
-$70,039
-$70,039
Savings
$233,936
$233,936
$233,936
$233,936
$233,936
Yearly Total
Savings
$163,897
$163,897
$163,897
$163,897
$163,897
Cumulative
Savings
-$100,355
$63,542
$227,439
$391,336
$555,233
Cooling Tower
WQ
F
Evaporation (E)
& Windage (W, cCW)
Cooling Water (CW, cCW)
Steam from
Turbine
Make-up
Water
(M, cM)
Cooling Tower
Blowdown (D, cCW)
Condensate
to Boiler
Process Supervisory Controller & Optimizer
SIMS
Estimated Project Payback Period: 1.6 Years
Estimated Project 5-yr Internal Rate of Return (IRR): 58%
Other
Uses
(e.g., Boiler)
Recycled Water (P, cP )
Concentrate (C, cC)