1

Princeton University Facilities Engineering

Environmental & Energy Study Institute

International District Energy Association

District Energy & Combined Heat & Power

at Princeton University

Rayburn House Office Building

Tuesday, April 21, 2009

Ted Borer, PE, CEM, LEEDAP

etborer@princeton.edu

Overview

Campus Energy Demands

E Pl t & Di t i t E S t Energy Plant & District Energy Systems

Combined Heat and Power Production

Plant Economic Dispatch

Historic & Projected Emissions

Opportunitiespp

2

Energy Demands at Princeton

> 150 Buildings

Academic

Research

Administrative

ResidentialResidential

Athletic

Energy Equipment & Peak Demands

Electricity Rating Peak Demand (1) Gas Turbine Generator 15 MW 27 MW( )

Steam Generation (1) Heat Recovery Boiler 180,000 #/hr (2) Auxiliary Boilers 300,000 #/hr 240,000 #/hr

Chilled Water Production (3) Steam Driven Chillers 10 100 Tons (3) Steam-Driven Chillers 10,100 Tons (5) Electric Chillers 10,700 Tons 13,800 Tons

(1) Thermal Storage Tank 40,000 Ton-hours *peak discharge 10,000 tons (peak)

3

Plant Energy Balance

PSEG Electricity

CampusEnergy Users

Gas Turbine&

HRSG

Duct Burner &

Electricity

Natural Gas

#2 Diesel Fuel Oil

Electricity

Steam

Backpressure Turbines

Chilled Water&

Thermal StorageSystems

&HRSG

AuxiliaryBoilers

ChilledWater

Biodiesel Fuel Oil

Campus District Steam System

4

Power T rbine

Fuel & Water

Combined Cycle “Cogeneration”

Gas Turbine

Turbine

Gearbox Electric Generator

Hot exhaust Gas

CO Catalyst

AC ElectricityAir

SteamFeed WaterHeat Recovery Boiler

Exhaust Gas

Princeton Power Demand With Cogen Dispatch To Minimize Cost

18

20

Generation

Campus Demand

6

8

10

12

14

16

Me

ga

wa

tts

.

p

Power Purchase

-2

0

2

4

6

08 Jul 05 08 Jul 05 09 Jul 05 09 Jul 05 10 Jul 05 10 Jul 05 11 Jul 05

5

Princeton Economic Dispatch System

PJM Electric Price Generate/Buy/Mix

ICETEC

NYMEX Fuel Price

Current Campus Loads

Weather Prediction

Production Equipment Efficiency &

Preferred Chiller & Boiler Selections

Preferred Fuel Selections

ICAP & Transmission Warnings

Availability

“Business Rules”

Operating Display & Historical Trends

Live feedback to Icetec

Operator Action

TES Economic Dispatch ScreenTES Economic Dispatch Screen

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THIS Is The Smart Grid

2005 Peak Grid Demand Hour: 27MW

2006 Peak Grid Demand Hour: 2 MW 2006 Peak Grid Demand Hour: 2 MW

This frees 25 MW of system capacity for use elsewhere by the local grid – and saves $$$!

HOW?...

CHP Power Generation

Steam-Driven Cooling

Thermal Storage

Demand-Side Management

Climate Change Legislation

Comparison of Legislative Climate Change Targets in the 110th Congress 1990 - 2050

Princeton Historic % of 1990 CO2

8,000

10,000

12,000

14,000

120%

140%

160%

180%

200%

220%

O2e

U

S E

mis

sio

ns

.Business as UsualBingaman-Specter w/ price CapBingaman-Specter, conditional targetLieberman-McCain and Oliver GilchrestLieberman-Warner draft outlineBingaman-Specter no price capKerry-SnoweSanders-Boxer, WaxmanKyoto ProtocolNJ Executive Order 54 (linear change)

-

2,000

4,000

6,000

0%

20%

40%

60%

80%

100%

1990 2000 2010 2020 2030 2040 2050

Mil

lio

n m

etri

c T

on

s C

O

Legislative source data estmated from World Resources Institute http://www.wri.org/usclimatetargets

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Reduced Chilled Water Use

Princeton University Chilled Water Load Growth

40M

illi

on

s 12

Mil

lio

ns

15

20

25

30

35

Ch

illed

Wat

er U

se (

To

n-H

ou

rs)

6

8

10

amp

us

Flo

or

Are

a (S

q.F

t.)

0

5

10

FY 88

FY 89

FY 90

FY 91

FY 92

FY 93

FY 94

FY 95

FY 96

FY 97

FY 98

FY 99

FY 00

FY 01Fy 0

2Fy 0

3Fy 0

4Fy 0

5Fy 0

6Fy 0

7Fy 0

8

Year

An

nu

al C

-

2

4 Ca

Chilled Water

Bldg Sq.Ft.

Reduced Annual Steam Energy

Princeton University Annual Steam Use

900

1,000

Mil

lio

ns 12

Mil

lio

ns

400

500

600

700

800

900M

An

nu

al S

team

Use

(lb

s)

6

8

10

Mam

pu

s F

loo

r A

rea

(sq

.ft.

)

0

100

200

300

FY 88

FY 89

FY 90

FY 91

FY 92

FY 93

FY 94

FY 95

FY 96

FY 97

FY 98

FY 99

FY 00

FY 01

Fy 02

Fy 03

Fy 04

Fy 05

Fy 06

Fy 07

Fy 08

Fiscal Year

A

-

2

4 Ca

Steam Use

Floor Area

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FY 2008 Summary

Goal: Return to 1990 CO2 emissions by 2020.

1990 Baseline: 105,000 short tons

FY 2007: 145,000 short tons

FY 2008: 128,000 short tons

12% improvement this year due to:12% improvement this year due to:

Improved energy production and delivery

Repairs & upgrades

Economic dispatch

PSEG accounting correction

2007 & 2008Energy Delivered & CO2 Emissions – Common Units

60 000

70,000

600 000

700,000

20,000

30,000

40,000

50,000

60,000

200,000

300,000

400,000

500,000

600,000

2007 2008

2007 2008

0

10,000

20,000

-

100,000

200,000

Million Btu Million Btu Million Btu Short Tons CO2

Short Tons CO2

Short Tons CO2

Delivered Power

Delivered Steam

Delivered Chilled Water

. Delivered Power

Delivered Steam

Delivered Chilled Water

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2008 vs. 2007 Changes

We purchased less energy but delivered more of it to campus.

Purchased power is ~1/3 of our CO2. PSEG changed CO2 accounting methodology to better reflect the mix of power delivered. That reduced our purchased power emission rate by 16%.

Campus power consumption (outside the plant) was reduced by ~ 5%.

There were 5% more heating & 2% more cooling degree-days ’08 vs.’07

We burned half as much diesel fuel and a little less natural gas.

We reduced thermal losses through repairs, insulation, trap & valve upgrades.

W i d d t f 67% t 83% We improved condensate recovery from 67% to 83%.

We ran the cogeneration system at a higher average efficiency (fewer hours on-line at low efficiency).

We used more “free cooling” and a lower-emission mix of chillers; (1% less steam and 14% more electric).

We used economic dispatch more effectively.

CO2 Reduction Goals

Low Flow Fixtures, 1% Lighting, 9%

HVAC/GSHP, 17%

Utilit Grid Red ctions

Unknown/Future Technology, 25%

Energy Conservation, 8%

Thermal Distribution Improvements, 8%Plant Efficiency, 14%

Biodiesel, 9%

Utility Grid Reductions, 9%

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Ongoing Opportunities

Ground Source Heat Pumps Ground Source Heat Pumps

Backpressure Steam Turbine-Generators

Cogen Plant Efficiency Upgrades

Real-time emissions calculation

CHW-HTW Heat Pumps

Biodiesel

Energy Star & Smart Start Programs

Thank you

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CO2 Emissions by Source

140

150

san

ds

Campus CO2 Emissions

70

80

90

100

110

120

130

rbo

n D

ioxi

de

Em

issi

on

sT

ho

us

-

10

20

30

40

50

60

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Sh

ort

To

ns

Ca

Net electric purchase (PSEG data)

Natural gas combustion

#6 oil combustion

#2 oil combustion

Gasoline combustion

Backpressure Turbine - Generators

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Chilled Water Campus Loop

Warm vapor

Chiller Cooling Tower

Cool ~ 70 F

Cold water To Campus ~ 41 F

Warm water from campus ~ 56 F Hot ~ 90 F

Warm vapor

Warm water from HTX or tank ~ 56° F

Warm

Chilled Water Thermal Storage

Thermal Storage Tank

water from Campus ~ 58° F

Cold water

Chiller Cooling Tower

Hot

Cool

Cold water To HTX or tank ~ 32° F Plate & Frame Heat Exchanger

To Campus ~ 34° F

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TES Tank Stratification

Reducing Cost and Emissions with TES

Purchase daily power at least cost Reduce energy use gy

High efficiency equipment selection Equipment operates at full load design point More efficient: lower night time wet-bulb temperature Reduced transmission losses Lower storage temp increased campus differential

temperature lower pumping energy required

Increase Reliability and Ease of Operation Increase Reliability and Ease of Operation De-coupled production from demand Increase night-time load, reduced daytime load Easier daytime maintenance Reduced peak demand Excellent low-load performance

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Growing Electrical Demand

Princeton University Electrical Use Growth

160 12

Mil

lio

ns

60

80

100

120

140

l Ele

ctri

cal U

sag

e (1

000

Mw

h)

6

8

10

M

amp

us

Flo

or

Are

a (s

q.f

t.)

0

20

40

FY 8

8

FY 8

9

FY 9

0

FY 9

1

FY 9

2

FY 9

3

FY 9

4

FY 9

5

FY 9

6

FY 9

7

FY 9

8

FY 9

9

FY 0

0

FY 0

1

Fy 0

2

Fy 0

3

Fy 0

4

Fy 0

5

Fy 0

6

Fy 0

7

Fy 0

8

Fiscal Year

An

nu

al

-

2

4 Ca

Electric

Floor Area

Campus and CHW Power Use

Princeton University Electrical Usage

160

60

80

100

120

140

cal U

se

(

Mill

ion

Kw

h)

Main Campus Electric

Electric to CHW

Campus Elec w/o ChW Plant

Linear (Main Campus Electric)

0

20

40

FY

79

FY

80

FY

81

FY

82

FY

83

FY

84

FY

85

FY

86

FY

87

FY

88

FY

89

FY

90

FY

91

FY

92

FY

93

FY

94

FY

95

FY

96

FY

97

FY

98

FY

99

FY

00

FY

01

Fy

02

Fy

03

Fy

04

Fy

05

Fy

06

Fy

07

Fy

08

Fiscal Year

Ele

ctri

c

Load increase averages 2.8 M kwh per year as of fy 2002.