Welcome Bluegrass ASHRAE Chapter Annual Spring Seminar
Power Demand 101 Britney Thompson, CEM Energy Engineer An Equal Opportunity University
Power Demand 101 Outline Campus Power Overview Defining Demand Demand Management Strategies Common Pitfalls Questions
Campus Power Overview University of Kentucky
University of Kentucky Campus Power Stats Electricity Cost Distribution of UK TOD Electricity Bill 0.09% Basic Service Charge ($) 12.70% Energy Charge ($) 6.90% Peak Demand as billed ($) 310,000,000 KWH 70 MW peak demand $20 million annual cost 28.5 % 8.52% 13.08% 58.71% Intermediate Demand as billed ($) Base Demand as billed ($) Taxes, Fees & Other 12-Month Total History of Electricity Charges Energy Costs $ 11,815,112.16 Total Demand Costs $ 5,735,699.02 Peak Demand (kva) $ 2,631,813.11 Intermediate Demand (kva) $ 1,714,906.54 Base Demand (kva) $ 1,388,979.37
An Equal Opportunity University 3 Substations 70 MW peak usage, 17+ miles of electric duct bank
History of Demand at UK
Defining Demand
Understanding Demand Energy consumption is measured in kilowatthours (kwh) Demand is measured in kilowatts (kw) or kilovolt-amperes (kva) Measurement is sampled every 15 minutes Highest 15-minute interval per billing period is used to set the demand charge Customer pays based on when the power is used Cost recovery mechanism for transmission and distribution infrastructure Could be 30-50% of electricity bill
The Checkout Lane Dilemma
Common Types of Rates Rates without Demand Fees Residential General Service: Less than 50kw Rates with Demand Fees Power Service: 50kw to 250kw Primary Secondary Time-of-Day Service: More than 250kw Primary Secondary Wholesale or Transmission Customers Not common in regulated market like KY
Residential Service No Demand Charge Slightly higher Energy Charge per kwh
Residential Service
Power Service One demand charge year round, all day Low energy charge per kwh
Power Service Secondary
Time of Day Primary Three demand levels each day, two different seasonal times Low energy charge per kwh
Time of Day Primary Summer Months: Peak: 1pm to Intermediate: 10am 7pm to 10pm Base Period: All Hours - 12am to 12am $4.26/kVA $2.76/kVA $1.71/kVA
Time of Day Primary
Watch Out for Minimums!
Demand Management Strategies
Blindfolded Tetris
16 kw peak 148 kwh used 6a 12p 6p 9p m
Take off the blindfold 148 kwh used 11 kw peak 6a 12p 6p 9p m
Use Your Building Automation Systems Campus Facility Management System: The Delta Room
Delta Room = Data, Data, Data Data Overload: 202,778 Points/Objects Monitored 106.6 million rows of data 971 Supply Fans Monitored Major Savings: Utility Bills Environmental Care Equipment Maintenance Programming Strategies: Duty Cycling Load Reset Night Cycle Optimum Start-Stop An Equal Opportunity University
UK White Hall Classroom Building 300kw 200kw 100kw Wednesday Thursday Friday Saturday Sunday Monday Tuesday
Load Duration Curve Courtesy Eric Wilson, Harshaw Trane
Demand Response Events Fayette County Public Schools Commercial Demand Management Programs Pays $25/kw average reduced over all events, up to 20 per summer 2,000 kw reduced = $50,000 Courtesy Logan Poteat, FCPS
Additional Strategies Thermal Storage Combined Heat & Power
Common Demand Pitfalls
Improper Sizing Oversizing a transformer can cost you every month Contracts are in place to ensure utility company recovers cost of infrastructure Be mindful of renovations Your power load may drop Your contract might charge you minimums
Improper Building Automation Use Turning everything on at once might set your demand for an entire month or year In the morning After power outage Don t Set It and Forget It
The Utility Company is Always Watching It only takes 15 minutes to set a peak for the month or even year Minimums look at highest billed demand over last 11 months
Power Demand 101 Review Campus Power Overview Defining Demand Demand Management Strategies Common Pitfalls Questions
Questions? Britney Thompson, Energy Engineer University of Kentucky britney.thompson@uky.edu Phone: 859-257-4171 Twitter: @EnergyUKY
Energy Storage for a Cooler Future Earl C. Rudolph CALMAC Manufacturing Corp. Maumee, OH Erudolph@calmac.com 38
Cool Storage The storage solution is: NOT so much about rates and rebates It is About: Right Sizing Cooling Systems Safety factor, Redundancy Sustainable (LEED) Design Emergency Cooling Lowering cooling costs 20% 40% Conserving cooling tower capacity Reducing Connected Load Reducing Pollution
Thermal Energy Storage For Off-Peak Cooling What is it? How does it work? Why is it Green? Other Green Advantages Applications/Case Studies
Off Peak Cooling Applications Schools Churches Community Homes Military Bases Offices Retail Stores Chiller Replacements Remodels & Additions Banquet Halls Theaters / Arenas /Auditoriums Hospitals / Surgical Centers Convention Centers Data Warehouses
Reduces electricity costs Demand and energy charges Smaller cooling equipment Smaller electrical service Less mechanical room space Meet increased loads without adding new cooling capacity Less maintenance Lower replacement costs
Decrease energy use Operate cooling equipment at best efficiency Eliminate inefficient part-load operation Take advantage of cooler nighttime temperatures Reduce distribution energy
Reduce source energy and emissions More efficient off-peak power generation Reduced transmission and distribution losses RP-991 showed attractive reductions in source energy using storage Ice storage up to 14% Emissions Efficiency
Increase operational flexibility Backup cooling source Adapt to changing electric rates Take advantage of dynamic electric rates Add dispatch options for central cool-heat-power plants Redundancy Rates Energy Storage Building Usage
Future Buildings will Need Storage = Coal and Oil can be stored for when we need it. = Clean Energy only good when wind blows or sun glows.
Utilization Rate Utilization Rate = Output / Nameplate Capacity Nuclear Coal Wind Solar Good Location Great Location 99% 90% 20% 15% 99% 90% 40% 25% 48
USA Utility Load* Factors 70 65 60 55 50 1955 1965 1975 1985 1995 2005 *Load Factor = Avg. Load Peak Load
K W ASHRAE 90.1 Base Building Non-Storage Electrical Profile 2000 1800 1600 1400 1200 1000 800 600 400 200 0 Cooling Pumps Fans Lighting Base Load Peak Load 2000 kw Avg. Load 1050 kw Total kwh = 28,000/day (Load Factor = 53%)
Design 30% better than 90.1 Non-Storage Electrical Profile Peak Load 1500 kw Avg. Load 800 kw Total kwh = 19,200/day (Load Factor = 53%)
Off Peak Cooling (OPC) Electrical Profile K W 2000 1800 1600 1400 1200 1000 800 600 400 200 0 Charging Storage 40% Peak Load Reduction 600 kw Shed Pumps Fans Lighting Base Load Peak Load 900kW Avg. Load 800kW Total kwh = 19,200/day (Load Factor = 88%)
Power continues to be less expensive at Night because of Generation Load Factor 4 Buildings x 1 Megawatt = 4 Megawatts 8,000 MW-h Sold 5 Buildings with TES @ 0.8 MW = 4 Megawatts 10,000 MW-h Sold!
Thermal Energy Storage For Off-Peak Cooling What is it? How does it work?
Partial Ice Storage System Similar to Chilled Water System Added: Blending Valve Diverting Valve Ice Tank(s) (No Moving Parts) Controls Heat Transfer Fluid Temperature Control Valves
SERIES FLOW CHILLER UPSTREAM Charging with Cooling Back Pressure Regulating Valve 58F 26F-22F V1 32-28F V2 Air Handlers 42F
SERIES FLOW CHILLER UPSTREAM Cooling Chiller Only 42F-58F Back Pressure Regulating Valve 42F-50F V1 42F 58F V2 Air Handlers P 42F
SERIES FLOW CHILLER UPSTREAM Chiller & Ice Cooling 42F-58F Back Pressure Regulating Valve 42F-50F 58F V1 42F 32F-42F V2 Air Handlers 42F
Stable Electric Rates Edison Electric Institute stated that the only form of Energy that has stayed the same cost or gone down in last 30 to 40 years has been Off-Peak Electricity
Keep It Simple (KIS) Simple Reliable Saves Money Chilled Water Reset..
Tons Tons Tons Chiller Return LCWT Setting Temperature Cool Day 55 Cool Day 50 Warm Day 50 Warm Day 55 Hot Humid Day 45 Hot Humid Day 60 100 90 80 70 60 50 40 30 20 10 0 100 90 80 70 60 50 40 30 20 10 0 ICE MAKING ICE MAKING FULL STORAGE ICE DISCHARGING Noon PARTIAL STORAGE Ice Priority ICE DISCHARGING Noon CHILLER PARTIAL STORAGE 100 Temperature Control Valves 90 80 70 60 50 40 30 20 10 0 ICE MAKING ICE DISCHARGING CHILLER Noon
Thermal Storage Tank Ice-on-Coil Internal Melt Tank Expansion Chamber Insulation Heat Exchanger
Thermal Energy Storage For Off-Peak Cooling What is it? How does it work? Why is it Green?
Real reasons Off-Peak Cooling is Green: 1. It is much more Energy Efficient to create and deliver a kwh of Electricity at night than during the heat of the day. Research from the California Energy Commission on 2 Cal. Utilities Reports 8 to 34% savings in raw fuel when comparing On and Off Peak Operation! Heat Rates for Base Load Plants ~7,800 Btu/kWh vs. Peaking Plants ~9,400 to 14,000 Btu/kWh 2. The last power plants to come on during peak hours are normally the dirtiest per kw Ashok Gupta (Director of Energy, NRDC) in NY Times article Peak Shifting results in lower emissions because some of the plants used to meet demand peaks are among the dirtiest in the city New CA Report by Greg Kats The Costs and Financial Benefits of Green Buildings states Peak power in CA is twice as dirty as Off Peak Power.
What about LEED? With TES a building will have Smaller refrigeration plant Less refrigeration required Lower probability of refrigerant loss to environment Utilizes base load-generated electricity Improved heat rates by generating at night Use less source and site energy Reduce CO2 emissions Less transmission & distribution losses off-peak Reduces need to build new generation as well as T&D infrastructure
Certified 40 49 points Silver 50 59 points Gold 60 79 points Platinum 80 points and above Sustainable Sites: Water Efficiency: Energy* & Atmosphere: Materials & Resources: Indoor Environment Quality: Base Points Possible 100 Innovation & Design: Regional Priority LEED TM Credits V3 NC 26 points 10 points 35 points 14 points 15 points 6 points 4 points points Indoor Environmental Quality Materials & Resources Energy & Atmosphere Water Efficiency Sustainable Sites *19 Energy Credits are based on ASHRAE 90.1 which is based on Energy COST Reduction
What about LEED? TES accrues points by reducing energy cost over a baseline building (up to 19 possible points in the E&A section credit one) Many LEED certified buildings have TES UC Merced, Merced, CA (GOLD) Bank of America, Troy, MI, Gold, NY, Platinum Hewlett Foundation: Menlo Park, CA (Gold) Fossil Ridge High School, Ft. Collins, CO (Silver)
Thermal Energy Storage For Off-Peak Cooling What is it? How does it work? Why is it Green? Other Green Advantages
Other Green Issues Safety Factors/Redundancy (Over-sizing) It is well documented that oversized chiller plants create less efficient real world operation. Engineers have to protect their licenses Storage is the natural solution
What about Design Safety Factor? 600 500 Design Day Cooling Load Profile Safety Factor (1) 500 ton? or (2) 250 tons? or (2) 300 tons? 400 Tons 300 200 100 0 Time
Safety Capacity on Design Day 600 Max Cooling Profile Conventional Cooling (2) 250 ton chillers Design Day Cooling Load Profile 500 400 Tons 300 200 100 0 Time
Safety Capacity on Design Day Design Day Load Storage System Excess Capacity Conventional System (2) 250 ton chillers Storage System (2) - 145 Ton Chillers 1400 ton-hrs. Storage 600 500 400 Tons 300 200 100 0 Time
Safety Capacity on Design Day Storage Chiller Stored Cooling Storage System Shortfall Storage System 1 (2) 145 Ton Chillers 1,400 ton-hr Storage 600 500 400 Tons 300 200 100 Conventional 1 (2)- 250 Ton Chillers 0 Time
What about the cost? Conventional Chiller Solution: (2) 250 ton chillers x $1500 / ton installed = $ 750,000 Ice Storage Solution: (2) 145 ton chillers x $1750 / ton installed = $ 507,500 1400 ton-hrs ice tanks x $150 / ton-hr installed = 210,000 Ethylene Glycol and controls = 75,000 Total = $ 792,000 Less Cooling Tower, Electrical, smaller piping = - $ 40,000 System Costs are about the same! Too much ice harms the economics
Costs of Storage What s the Installed Cost of a ton of Chiller Plant? $1000/ton,$1200/ton,$1400/ton,$1600/ton,$1800/ton Storage Costs installed ~ $100 to $150 per tonhr Depending on location, application and design For each 1 ton of chiller you reduce you need about 8 to 9 ton-hrs of storage. Costs are about the same
Site Energy Savings Case Study Kraft Headquarters, Chicago, IL. Two 500,000 SQ. ft. buildings in Suburban Chicago First building built late 1980 s Centrifugal chillers 42 chilled water 55 VAV supply air Second building built 1991 Thermal Storage/screw chillers 48 supply air
Site Energy Savings Case Study Kraft Headquarters, Chicago, IL. System Demand KW Annual KWH Annual Bill Ice Storage 2,368 10,114,460 $818,738 Conventional 3,307 11,695,468 $1,011,658 Storage can reduce air conditioning kw-h by up to 14%
Thermal Energy Storage For Off-Peak Cooling What is it? How does it work? Why is it Green? Other Green Advantages Applications/Case Studies
JC Penney Headquarters Plano, Texas
JC Penney World Headquarters 2,800,000 s.f. office and administrative, 5-1050 ton Trane chillers Ice storage - 177 IceBank tanks, 27,000 ton hrs Aprox. $400,000/yr savings
Durst Headquarters Retrofit 1155 Avenue of the Americas 41 Stories 3400 Ton Hours Storage Avoids 600kW out of 3500kW Original Total
Durst HQ Building 0.7 MW Reduction for one Building
TO LOAD ~1200 TONS FROM LOAD Ice Plant in Series with Water Chiller HX 490 ICE-MAKING TONS DEMAND LIMITED TO 700 TONS TS ICE STORAGE ICE STORAGE VFD PUMP
UL 8,000 Ton-Hr 2.5 days to install $365,000/yr
Ice Storage in a box For Example: 180 ton peak load package 100 ton chiller (1) model 1500 tank (2) valves, modulating, diverting (1) pump, expansion tank Controls and flat panel display
Ice In a Box has been done!
Benefits Remove engineering hours Removes perceived engineering risks Factory quality control Factory startup provides commissioning and fast startup Single Source responsibility Affordable $1,200 / ton! Connected load lowered by 96kW (180-100 tons) x 1.2 kw/ton Lower operating costs
Fossil Ridge High School LEED Silver and 1 st Place ASHRAE Award 2008 260,000 ft 2 conditioned Space Grades 10-12 1800 Students Peak Load 250 Tons 1040 sq. ft. / ton Actual Chiller 130 Tons 1280 Ton Hrs Ice Storage 2000 sq. ft. / ton
Fossil Ridge Green Design Results Fort Collins H.S. Fossil Ridge H.S. 288,192 sq.ft. 1,800 students 296,375 sq.ft. 1,800 students 800 kw Peak 428 kw Peak Energy Star Rating 48 Energy Star Rating 87 3 Watts / sq. ft. 1.65 Watts / sq. ft. $120 / sq. ft. $118 / sq. ft. Uses 30% kwh LESS $32,000 Less spent on Electricity $ 74,000 less on liquid fuels 90
Credit Suisse 11 Madison Ave. 30 Stories, 2.2 Million Ft 2 6200 Ton Hours Storage Savings ~ $1,000,000/year Avoids ~ 1000 kw Main reason for Storage: Resiliency 91
Bank of America Tower ICEBANK Facts Over Half a Million Pounds of Ice made every night. Enough Ice to Cool 250 Homes 1000 Tons of Air Conditioning Shifted to Off- Peak
Rockefeller Center NYC 9,000 Ton-Hr
Blattner Energy Inc. Avon, MN LEED Platinum Ground source heat pumps with IceBank energy storage 42% energy savings over conventional cooling 52,000 sq.ft 90 wells 180 ft deep 94
University of Arizona Campus Statistics 28,300 Tons of Refrigeration 12 Million Sqft. 130 Buildings 35 MW Peak 14 MW of Gas Turbine Gen. 14,000 ton-hr of Ice Storage Main reason for Storage: Optimizing Gas Turbine Generator s Efficiency Emissions and Heat output
Making and using ice July 1, 2004 14,000 ton-hr Added 60 tanks in 2006, now 162 total
Comparison of ice tank farm to cooling tower space/volume
Summary Owners and regulators are demanding designs that impact the environment and wallet less while improving occupant health and productivity. Construction and real estate businesses are realizing that green design is a good business practice.
Summary Sustainable designs are a team effort and are not cost prohibitive Instead of adding 20-30% to estimated load, reduce by 20-30% and add storage for safety at no extra cost. Cool Storage earns LEED points in E&A section, reduces operating costs, load on the grid, and environmental impact of cooling.
SKyPAC Bowling Green, KY
SKyPAC System Details Peak cooling load 279 tons 16 cooling hours 8 ice making hours 179 ton air cooled chiller 931 ton hours ice storage Supply 39 F, return 54 F 25% ethylene glycol Partial Storage
SkyPAC Benefits On peak demand reduced by 120 kw LEED Points 58% night time electricity discount
Daytime Nighttime $ 2.49/gallon $ 1.05/gallon When Would you Fill-up?
Tom Abele Business Unit Leader Building System Solutions Harshaw Trane people. purpose. performance.
60% THERMAL LOSS WHAT IS THE EFFICIENCY OF THE GRID 1 BTU IN.3 BTU OUT 27% TO 30%.3 BTU Generated.27 BTU Delivered 7% - 10% DISTRIBUTION LOSS
The Wall Street Journal 4/21/15
Combined Heat and Power Cycle 100 Units Fuel 33 Units Electricity Electric Load 46 Units Electricity Generator Combined Heat and Power 100 Units Fuel 56 Units Fuel 45 Units Heat Thermal Load 45 Units Heat Boiler 50% Efficiency 91% Efficiency
Historical Low Prices Growing domestic production has weighed on U.S. natural gas prices since the end of last decade
Natural Gas vs. Coal Mounting regulations on coal-fired generation is leading a large build-out of new gas-fired capacity
PJM Power $/MWh Natural Gas vs. Electricity Electricity prices in markets with a large percentage of natural gas-fired generation closely follow the cost of natural gas $120 $105 $90 $75 $60 $45 $30 PJM Power Price vs. NYMEX Natural Gas Price $14 $12 $10 $8 $6 $4 $2 Gas $/MMBtu PJM Power NYMEX Gas 111
Coal Plant Retirements Coal Retirements Total U.S. coal capacity = 305,700 MW 22,778 MW capacity (approx. 7%) already retired 2009-2013 Additional 27,143 MW (approx. 9%) planned for retirement 2014-2022
Steam Turbine Reciprocating
Large Gas Turbine Micro Turbine
CHP Application Hot Water and Steam Recovery Saturated steam Fuel Exhaust Gas ~900 F 392 F Condensate Load Electric Power Feeder tank 203 F 200 F CAT 170 F Engine High Temp. Circuit 190 F To Customer Engine Low Temperature Circuit (130 F) 160 F From Customer Remote Radiators
CHP Sizing and Applications Electric Peak Load The maximum power consumption in a 15-minute window at any point in time for a billing period. Many consumers have to pay a fee based on this maximum power demand. 1,150 kw Peak Load 500 kw Base Load
CHP Sizing and Applications Electric Base Load The minimum power demand at any point in time. If generator capacity exceeds base load, sell excess to grid. If base load exceeds generator capacity, self consume. 650 kw Base Load 500 kw Base Load
Improve Power Quality Improve Utility Efficiency(s) Eliminate Process Power Interruptions ISO 50001 Environmental Stewardship Lower Demand Costs Economic ROI Reduced Boiler Usage
Sample Economics Spark Spread / Technology Grid Load CHP $0.07/kWh $896,000 1.6 MW @ 8,000 Hours 12,800 MWh $314,000 E + $150,000 M $464,000 Total 78% Eff. 42,700 MBH $307,000 $273,000 $5.00/MCF Combined Utility Costs $1,169,000 D $771,000 $ 398,000/Yr. Savings
Financial Overview Investment(s) Return(s) CHP Investment $1.8M Annual Net Save $398k Annual O&M $150k Annual Reliability $XM Fed Tax Credit $180k Annual CO 2 2,200 Tons Simple Payback??? Proprietary & Confidential
Alternatives to Capital Power Purchase Agreements (PPA) KY PSC Staff Opinion Allowed? Capital Lease Typically Same Balance Sheet Treatment as CAPEX Operating Lease Must Pass FASB 13 Difficult Test Rental Solution Containerized Solutions with Rental Agreements Designed for Positive Cash Flow Capital Purchase with Incentive State and Federal Grants Federal Tax Incentives
Fort Knox Example - Project Summary 20 MW New Diesel Emergency Generation 16 MW New Natural Gas Peak Shaving Generation 8 MW New CHP Generation 44 MW New Emergency Power Generation Construction Cost $59,800,579 Peak Demand Savings $2,223,890 CHP Savings $4,979,054 Curtailment $ 728,093 Operational Savings $2,100,000 Total $10,031,037 Simple Payback 5.96 Years (Less than 4 years without Diesel) 122