Case Studies of District Cooling Operating and Capital Cost Savings Using Chilled Water and Low Temperature Fluid TES

Transcription

1 Case Studies of District Cooling Operating and Capital Cost Savings Using Chilled Water and Low Temperature Fluid TES John S. Andrepont, President The Cool Solutions Company George Berbari, CEO DC PRO Engineering L.L.C. IDEA Cooling Symposium Dubai, U.A.E. October 29, 2007

2 Outline Thermal Energy Storage (TES) Technology types, and their pros and cons Surveys of TES Use in DC Systems The Numerous Benefits of TES Case Studies of Sensible Heat TES Savings in operating and capital costs Summary Conclusions

3 Nomenclature CHP CHW CHWS/R CW DC HW LTF RTP TES TIC TOU Combined Heat & Power Chilled Water Chilled Water Supply/Return Condenser Water District Cooling Hot Water Low Temperature Fluid Real-Time Pricing Thermal Energy Storage Turbine Inlet Cooling Time-of-Use

4 Types of TES Ice TES (latent heat) Water is converted to ice off-peak; then ice is melted on-peak Conventional or Low Temp CHWS possible (34 to 44 ºF typical) Chilled Water (CHW) TES (sensible heat) An insulated tank with cooler denser CHWS stratified below warmer less dense CHWR Conventional CHWS temps (39 to 42 ºF typ.) Low Temp Fluid (LTF) TES (SoCool ) Similar to CHW TES, but using fluid <39 ºF Lower supply temp (30 to 36 ºF typical)

5 Inherent Characteristics of TES Ice CHW LTF Volume good poor fair Footprint good fair good Modularity excell poor good Economy-of-Scale fair excell good Energy Efficiency fair excell good Low Temp Capability good poor excell Ease of Retrofit fair excell good Rapid Charge/Dischrg Capability fair good good Simplicity and Reliability fair excell good Can Site Remotely from Chillers poor excell excell Dual-use as Fire Protection poor excell poor

6 Highlights of Surveys - TES in DC Campus DC Thermal Utility DC Time period through 2005 through 2006 Total DC-TES: No. of TES 159 (124 sites) 106 TES capacity 1,808,408 T-hrs 2,610,815 T-hrs Average per DC system: TES capacity 14,584 Ton-hrs 24,630 Ton-hrs cooling shift 2,083 Tons 3,519 Tons electric shift 1.6 MW 2.6 MW

7 Highlights of Surveys - TES in DC Campus DC Utility DC Chronologic: ,000 T-hrs 24,500 T-hrs ,300 T-hrs 102,533 T-hrs ,127 T-hrs 509,373 T-hrs ,024 T-hrs 879,048 T-hrs ,000 T-hrs 828,169 T-hrs Rapid growth apparent in and beyond, including non-u.s. markets (e.g. Mid-east, E. Asia)

8 Highlights of Surveys - TES in DC Campus DC Utility DC Geographic: U.S. 1,677,048 T-hrs 1,883,347 T-hrs non-u.s. 131,360 T-hrs 730,000 T-hrs TES Technology: Sensible Heat 1,418,479 T-hrs 1,697,983 T-hrs (CHW & LTF) 78% 65% Latent Heat 389,929 T-hrs 912,832 T-hrs (Ice) 22% 35%

9 Traditional Benefit of TES Peak Load Management Reduce peak cooling demand Reduce (or eliminate) on-peak cooling demand Reduce on-peak electric demand costs Shift cooling use from on-peak to off-peak Reduce time-of-day electric energy costs Net Result: operating energy cost savings

10 Secondary Benefits of TES Secondary Applicable Benefits of TES TES Types Peak demand mgmt / oper cost saving all TES Balances thermal & elec for CHP econ all TES On-site effic y (night cond.; no low load) all TES Source fuel and emission reductions all TES Improved flexibility of opers & maint all TES Emergency back-up cooling all TES

11 More Secondary Benefits of TES Secondary Applicable Benefits of TES TES Types Emergency condenser water make-up CHW TES Expanded free cooling capability CHW TES Fire protection water storage CHW TES Skyline advertising (using tall tanks) CHW or LTF Smaller district pipe (w/ satellite TES) CHW or LTF Less pump (& fan) HP (low temp supply)ice or LTF Water treatment (corrosion & microbio) LTF TES

12 A Surprising Benefit of TES Surprise Benefits of TES Capital cost savings vs no TES during: 1. new construction 2. major renovation Applicable TES Types CHW, LTF, or Ice w/ LoTemp Air Big capital savings vs no TES during: 1. new construction 2. retrofit expansions 3. chiller plant rehab Large applications of CHW or LTF

13 The Value of Load Shaping Reality: elec cost and value vary with time. Day-night variation is very significant. Energy providers do feel those variations, even when selling via flat rate $/kwh. Consumer can use TES to shape demand to be an attractive buyer, at lower $/kwh. Or, TES can maximize value w/ other rates: demand, TOU, RTP, or market purchases. (Expect TOU rates to come to the GCC.)

14 Modest Footprint of TES m 2 /Ton CHW Plant (typical, rule-of thumb) 0.15 Very compact modern CHW plant ,000 T-hr CHW tank, Doha (or 36,000 T-hr as SoCool LTF) ,000 T-hr LTF tank, Chicago ,000 T-hr CHW tank, Riyadh CHW & LTF TES do not need big footprint. And they can be remote from chiller plant.

15 Efficiency & Emission Benefits On-site energy efficiency Inherent inefficiencies of TES can be small: e.g. ambient heat gain + extra pumping energy Inherent efficiencies of TES can be larger: night condensing + no low load ops (+ more free cool) Some TES document 5 to 15% less annual kwh/t-h Source power plant efficiency & emissions TES shifts the power plant that is on the margin : From on-peak = high fuel use & high emissions To off-peak = low fuel use & low emissions Fuel, SO 2, NO X, CO 2 often reduced 15 to 20% or more!

16 TES is best available energy storage utility-scale supply-side demand-side sodium-sulf. CHW TES CHW TES battery turbine cool DC utility Location W. Virginia Saudi Arabia Florida Year in operation Peak shaving 1.2 MW 48 MW 15 MW Energy storage 7.2 MWh 288 MWh 120 MWh Projected life 15 years 30+ years 30+ years Utilization efficiency 90% near 100% near 100% Classification pioneering commercial commercial Unit capital cost unreported $65/kW $200/kW (per unit storage) unreported $11/kWh $25/kWh

17 Climaespaço District Cooling Utility Lisbon, Portugal 1997 new construction Reduced chiller plant by 5,687 T (50%) 39,800 T-hrs of CHW TES (partial shift) Load mgmt: 5,687 T and 4 MW Operating Saving: $1.16 million/yr Capital Saving: $2.5 million (31%) TES improved economics of CHP (cogen).

18 University of Alberta University Campus Alberta, Canada 2005 retrofit capacity expansion Avoided 6,300 T satellite chiller plant 60,000 T-hrs of CHW TES (partial shift) Load mgmt: 7,200 T and 5.8 MW Operating Saving: ~$600,000/yr (12%) Capital Saving: $4 million (30%) TES also aids CHW distribution network. TES can convert to LTF, for 70% increase.

19 60,000 T-hrs CHW TES at 41 ºF (102,000 T-hrs LTF TES at 32 ºF) 7.9 million gals Alberta, Canada

20 Chrysler Motors Corporate R&D Campus Michigan, USA 1990 new construction (200,000 m 2 ) Reduced chiller plant by 6,300 T (36%) 68,000 T-hrs of CHW TES (partial shift) Load mgmt: 7,600 T and 5.3 MW Operating Saving: $1 million/yr Capital Saving: $3.6 million TES also provides fire protection.

21 Dallas/Fort Worth Int l Airport Airport Cooling Network Texas, USA 2003 new CHW plant, airport expansion Enhanced plant capacity by >15,000 T 90,000 T-hrs of Low Temp Fluid (LTF) TES Load mgmt: up to 25,000 T and 17.4 MW Operating Saving: cut on-peak dmnd 85% Capital Saving: $6 million LTF aids CHW distribution and water trtmt.

22 90,000 T-hrs LTF TES at 36 ºF 6.0 million gals Dallas/Fort Worth, Texas

23 OUCooling District Cooling Utility Florida, USA 2002 new DC, for conv. ctr. expansion Avoided 10,000 T chiller plant addition 160,000 T-hrs of CHW TES (near full shift) Load mgmt: 20,860 T and 16.6 MW Operating Saving: over $500,000/yr Capital Saving: >$5 million (TES<$200/T) TES can convert to LTF, for 56% increase.

24 160,000 T-hrs CHW TES at 40 ºF (250,000 T-hrs LTF TES at 32 ºF) 17.6 million gals Orlando, Florida

25 Saudi Electricity Company (SEC) Turbine Inlet Cooling (TIC) Riyadh, KSA 2005 new TIC, for existing gas turbines Reduced chiller plant by 20,000 T (65%) 193,000 T-hrs of CHW TES (full shift) Load mgmt: 31,000 T and over 30 MW Operating Saving: over 30 MW Capital Saving: well over $10 million TES-TIC increases net power output 30%, when utility needs it most (6 hrs/day)

26 193,000 T-hrs CHW TES at 45.5 ºF 7.9 million gals Riyadh, Saudi Arabia

27 Field Data - Fully Charged TES Tank

28 Field Data - Fully Discharged Tank

29 Major GCC TES Tanks Capacity T Current (Ton-Hour) ( F) Status Project Location <10,000 ~ Completed Kingdom Centre Riyadh, KSA 15, Completed T2 Abu Dhabi, UAE 2 x15, Completed T3 Abu Dhabi, UAE 15, Completed T4 Abu Dhabi, UAE 15, Completed T6 Abu Dhabi, UAE 25, Completed T5 Abu Dhabi, UAE 18, Completed Dhafra Air Base Abu Dhabi, UAE 15, Completed GIC Abu Dhabi, UAE 41, Completed DIP Plant 6 Dubai, UAE 2 x 41, Construction DIP Plant 3 Dubai, UAE 2 x 38, Construction Motor City Dubai, UAE 40, Construction Danet Abu Dhabi Abu Dhabi, UAE 13, Construction Worker s Village Abu Dhabi, UAE 32, Design Building Material City Abu Dhabi, UAE

30 Major GCC TES Tanks Capacity T Current (Ton-Hour) ( F) Status Project Location 32, Design Al Reef Down Town Abu Dhabi, UAE 25, Construction Al Rashid Mall Khobar, KSA 193, Completed SEC Riyadh, KSA 28, Completed West Bay Plant 1 Doha, Qatar 20, Construction West Bay Plant 2 Doha, Qatar 730,000 Ton-Hr and growing.

31 Summary of Savings Examples TES Capacity Oper Svg Capital Svg Type (Ton-hrs) Location (millions) (millions) CHW 15,000 U.A.E. Unknown $1.5 CHW 28,000* Qatar Unknown $2.2 CHW 39,800 Portugal $1.16/yr $2.5 CHW 60,000* Canada $0.6/yr $4 CHW 68,000 U.S.A. >$1/yr $3.6 LTF 90,000 U.S.A MW $6 CHW 160,000* U.S.A. >$0.5/yr >$5 CHW 193,000 K.S.A. >30 MW >$10 * pre-designed to expand (40-70%) from CHW to LTF

32 Conclusions Sensible (CHW and LTF) TES (in large applications) will reduce operating costs and capital costs. Very large applications yield multi-million $ savings. Examples cover a broad range of applications: TES serving 2,000 to tens-of-thousands of Tons Industrial, hi-tech, institutional, airport, DC, TIC, etc. Locales from US & Canada to Europe, Asia and GCC Arid & humid climates; long & short summers To capture savings, use sensible heat TES with: 1. New construction or retro expansions or rehab s 2. Chillers sized to peak day average load (not peak load) 3. Maximized CHW supply-to-return Delta T

33 Questions / Discussion? Or for a copy of this info, contact: John S. Andrepont The Cool Solutions Company [email protected] tel: George Berbari DC PRO Engineering [email protected] tel: +971-(0)