CHILLED WATER THERMAL ENERGY STORAGE NEW MEXICO

Transcription

1 CHILLED WATER THERMAL ENERGY STORAGE NEW MEXICO

2 HELLO

3 Do you own a Thermal Energy Storage Tank?

4 Energy Storage Energy is stored during off-peak periods, then distributed during peak periods. Examples of energy storage systems: Batteries in a mobile phone Hot water heaters The human body Thermal Energy Storage (TES) Tanks

5 U.S. Electric Grid

6 SOLAR WIND NUCLEAR COAL HYDRO NATURAL GAS BIOGAS Generation and Transmission ELECTRIC GRID Distribution and Consumption RESIDENTIAL COMMERCIAL HOSPITALS & Central Utility Plant AIRPORTS & Central Utility Plant SCHOOLS & Central Utility Plant

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8 as more intermittent renewable power (wind and solar) is added to the grid more energy storage will be required to smooth out the electric load

9 Examples of Large Scale Energy Storage Technologies Pumped Hydro Battery Compressed Air Flywheel Thermal Energy Storage (TES)

10 Comparison of Energy Storage Options Energy Storage Tech Useful Capital Costs Technology Maturity Eff (%) Life (Yrs.) ($/kwh) Pumped Hydro mature Na-S Batteries mature Lead-acid Batteries mature Li-Ion Batteries new Flywheels demo Compressed Air demo Chilled Water TES mature * TES has the lowest initial cost and longest useful life

11 SOLAR WIND NUCLEAR COAL HYDRO NATURAL GAS BIOGAS Generation and Transmission ELECTRIC GRID Distribution and Consumption RESIDENTIAL COMMERCIAL HOSPITALS & Central Utility Plant AIRPORTS & Central Utility Plant SCHOOLS & Central Utility Plant

12 Central Utility Plant Equipment

13 Chilled Water District Cooling Systems

14 Chilled Water Systems with Thermal Energy Storage (TES) The TES tank is like a big battery

15 Thermal Energy Storage (TES) Ice Storage Stores thermal energy in an ice phase Requires smaller footprint Modular for ease of expansion Stratified Chilled Water Stores thermal energy in the chilled water phase Economical in larger applications (>3,000 ton-hrs) Simple to operate & maintain

16 TES Tank Applications College Campuses Edinburg, TX - UT Cypress, CA College Orlando, FL - UCF Government and Municipalities Lackland AFB, TX Danville, PA - Geisinger San Antonio, TX - Airport Ashburn, VA DFP Raleigh, NC Front Royal, VA - Dominion Private Industry, Power Plants, and Data Centers

17 TES with Chilled Water District Cooling Systems TES tank is like a big battery

18 Chilled Water TES Concept

19 Stratified Chilled Water

20 Daily Operation of a TES Tank

21 Stratification of the Chilled Water 1 Hour into the Discharge Cycle Thermocline

22 Some of the Benefits of TES Tanks Energy Cost Savings and Incentives kw Savings permanent electric demand reduction kwh Savings reduces consumption for cooling Incentives from the utility one time rebate for a TES project Cost Avoidance when expanding the campus or replacing a chiller, instead of adding another chiller, install a TES tank Mission Critical Back-up Reservoir of chilled water ensures no downtime Dual purpose fire water storage tank

23 Electric Load Profile LOAD PROFILE WITHOUT TES

24 Electric Load Profile LOAD PROFILE WITHOUT TES LOAD PROFILE WITH TES Load Reduction With TES: permanent electric load shift from peak periods to off-peak periods energy reduction by taking advantage of cooler ambient conditions at nighttime and running chillers at their optimum conditions

25 Public Service Company of NM Utility Rate On-Peak Off-Peak Large Power TOU $25.43/kW $18.27/kW $0.030/kWh $0.016/kWh Large Power (>3,000kW) $24.23/kW $15.59/kW $0.013/kWh $0.007/kWh Large Power (>8,000kW) $18.90/kW $11.47/kW $0.033/kWh $0.015/kWh Incentives Peak Shaver Program

26 Cost Avoidance Campus Expansion Projects Instead of adding more chillers, pumps, & condensing equipment Utilize the excess cooling capacity of the existing central plant equipment, and add a TES tank Lowers the initial capital cost & reduces O&M

27 Mission Critical Back-up Reservoir of cold water for cooling servers in case data center chillers go offline unexpectedly Dual purpose TES and fire water storage tank can lower insurance premiums

28 CASE STUDY #1

29 Orlando, FL University of Central Florida Project Drivers: Major expansion Energy cost containment Scope of Work: New 3.0 MG TES tank with 26,200 ton-hrs of energy storage capacity New CHW pumps, piping, and control strategy

30 Orlando, FL University of Central Florida Project Results: Estimated annual energy cost savings of over $700,000 Rebate from the utility company of $637,000

31 CASE STUDY #2

32 Lewisburg, PA Bucknell University Project Drivers: Major expansion Energy cost containment Existing Central Plant Equipment: 4.8 MW gas turbine, 70,000 lbs/hr HRSG 1.2 MW steam turbine generator 2,400 tons electric chillers New Thermal Storage: 0.9 million gallon TES tank with 6,500 ton-hrs of energy storage capacity New controls strategy

33 Peak Demand Reduction with TES Megawatt Reduction Sep-14 2-Sep-13 and the TES tank now provides the additional cooling capacity required for the campus expansion

34 Best Practices

35 To Minimize the TES Tank Size Maximize the Chilled Water ΔT

36 TES Tank Volume (Gallons) Chilled Water ΔT ( F) TES Capacity (Ton-hrs) 5, , , , , , ,000 10,000 1,600,000 1,333,000 1,143,000 1,000, , ,000 15,000 2,400,000 2,000,000 1,715,000 1,500,000 1,333,000 1,200,000 30,000 4,800,000 4,000,000 3,430,000 3,000,000 2,667,000 2,400,000 50,000 8,000,000 6,670,000 5,720,000 5,000,000 4,450,000 4,000, ,000 16,000,000 13,330,000 11,430,000 10,000,000 8,900,000 8,000,000 Increasing the chilled water ΔT, reduces the TES tank size

37 Instrumentation Inside a TES Tank Level Sensor Thermocline Temperature Sensors

38 Instrumentation Temperature Sensors Reputable sensor manufacturer Submersible Can communicate directly to the central plant controls Mounted vertically in the tank every 2 or 3 feet Accuracy should be within ± 0.1 F. Level Sensors Reputable sensor manufacturer Ultrasonic Type mounted on the roof of the tank Pressure Type mounted at the bottom of the tank Can communicate directly to the central plant controls Accuracy should be within ± 0.2 inches

39 Chilled Water Treatment and Filtration Work with a reputable chemical treatment and filtration company who has experience with TES systems Chemically treat the water for rust inhibition and to limit microbial growth Filter the chilled water to eliminate build up of biologicals that can attack chilled water system components

40 Water Level in the TES Tank If possible, dimension and site the tank so that the water level in the tank is above the highest point in the rest of the chilled water system. This will ensure that the chilled water will not overflow out of the tank during de-energized periods. However, if the water level in the tank is below the highest point in the chilled water system, then a heat exchanger can be added to de-couple the tank from the system, or pressure sustaining valves added to prevent overflow.

41 Value-added Benefits of Concrete TES Tanks Lowest life cycle cost (no repainting the interior) Watertight & maintenance-free Tanks can be partially or fully buried Energy efficient design Investment in the local economy Numerous architectural enhancements

42 Concrete vs. Steel Concrete Tanks Lowest life cycle, built with materials that will not degrade over time Can be partially or fully buried No long lead time on materials Over 50% of the cost of the tank is from local labor and suppliers Steel Tanks Maintenance may be required (to repaint the interior walls and underside of roof) Cannot be partially or fully buried Long lead materials Steel plate shipped in from an overseas factory

43 Benefits of a Partially Buried Tank Can be differentially buried into a sloping hillside Reduces the amount of exterior wall insulation that is required, lowering the cost of the tank Minimizes the overall tank height above grade Can reduce the cost of site preparation because tank can be built slightly below grade and at the optimum depth based on soil conditions

44 Benefits of a Fully Buried Tank No exterior insulation required, reducing the cost of the tank Tank is completely out of sight Owner has use of the real estate above the tank

45 TES Tank Design - Elevation Diffuser and distribution piping SS hangers and supports Dome or flat roof.

46 Octagonal diffuser piping Distribution piping TES Tank Design - Plan

47 Anatomy of a Watertight Tank Precast Concrete Corewall Embedded Steel Diaphragm Multiple Layers of Wire Prestressing Seismic Restraints Flexible Floor-wall Connection

48 Flat or Dome Roof TES Tanks Column-supported Free span

49 Custom Designed Diffuser SS Hangers and Hardware Distribution Piping Octagonal Diffuser Piping

50 Exterior Insulation & Finishing System (EIFS)

51 Numerous Enhancement Options

52 Multi-Color

53 Blend in with the Campus

54 Blend in with the Environment

55 Multi-color with Unique Patterns

56 Observation Deck

57 2 x 5.0 MG Tanks Equipment on Roof

58 2.0 MG TES Tank Under a Parking Lot

59 Free TES Tank Renderings

60 Info Required for Sizing & Budgeting XX,XXX ton-hrs of useable cooling capacity XX F chilled water ΔT of the system

61 Info Required for a Firm Price TES tank criteria (ton-hrs, CHW ΔT, CHW flow rate) Above ground, partially buried, fully buried Site limitations work area, max. height Soil conditions geotechnical report Exterior enhancements painted logo, faux brick, etc. Approximate construction start date Special site constraints or schedule requirements

62 Guy Frankenfield Energy Division Manager M (214)