Energy Storage in Chicago Lowering Peaks to Reduce Utility Bills Evan Berger Director of Energy Solutions, North America Calmac Corp. eberger@calmac.com November 2017 1
Utility Bill Basics 1. There are three ways to lower electric costs: a) Buy fewer units of energy. b) Purchase it when it s cheaper, at night. c) Negotiate a better rate with your 3 rd party supplier.
Utility Bill Basics 2. Commercial Rates are Different than Residential Rates: a) Residential Rates are based solely on usage (kwh) b) Commercial Rates are based on a mixture of usage (kwh) and Demand (peak kw).
Utility Bill Basics 3. Rates and tariffs are complicated. Why? A few possible* reasons come to mind a) Lawyers write them b) Regulators dislike plain English c) The less customers know about their electricity bills, the more utilities and Third-Party Suppliers can possibly* earn more money at their expense *Note: pure speculation
Demand Charges Definition: any electricity charge that is assessed on a per-kw basis Types of Demand Charges: 1. Utility Demand Charges 2. Grid Demand Charges (from PJM, NYISO, etc.) Note: more o)en than not, Grid Demand Charges are blended in Third Party Supplier bills and thus not visible to the customer; we ll discuss this issue at great length later in the presentadon
Let s Look at John s ComEd Bill
Nonresidential Sample Hourly Supply Bill
Nonresidential Sample Hourly Supply Bill Note: view in slideshow mode Altogether, Demand makes up 44.6% of the pre-tax bill
Utility Demand Most buildings have a bell shaped load curve Traditional Cooling 1,400 kw 1,200 kw 1,000 kw 800 kw 600 kw 400 kw 200 kw 0 kw Monday Tuesday Wednesday Thursday Friday 88 89 86 92 86 Typical Office Building U"lity demand is based off the peak interval (30 mins) in a given billing month Always occurs on the ho?est weekday a@ernoons cooling sets the peak
Calculating GRID Demand Introducing the Grid PJM Interconnec3on PJM is the world s largest grid, covering 13 states from the Mid-Atlantic all the way down to North Carolina and over to Illinois PJM schedules the reliable flow of power from generators to consumers and charges customers for the service
Calculating GRID Demand PJM Capacity Charges are based on a customer s Peak Load Contribu"on (PLC); it is calculated based on the customer s consump"on during the five highest hours of total Grid demand (kw) during the previous year. These are known as the 5CPs the five Coincident Peak Hours
Calculating GRID Demand The 5CPs have always occurred during Summer a?ernoons 5CP Chart, 2010-2016 2016 2015 2014 2013 2012 2011 2010 July 25, 3-4pm July 20, June 17, 5-6pm July 15, 5-6pm July 5, 3-4pm June 8, July 6, July 27, July 28, June 18, July 16, July 6, July 19, July 7, August 10, July 29, July 1, 5-6pm July 17, July 16, July 20, July 23, Aug. 11, 3-4pm Aug. 17, 2-3pm Sept. 5, 3-4pm July 18, July 17, July 21, Aug 10, Aug. 12, 3-4pm Sept. 3, July 22, 5-6pm July 19, 2-3pm July 18, 2-3pm July 22, 2-3pm Aug 11,
Calculating GRID Demand PJM Demand Charges are Ratcheted Ratcheted: Once you set the Demand kw, it stays at that level on your bill for a full year. Note: Some utility Demand Charges are also ratcheted
Comparison: Traditional Cooling vs. Load Shifting Results derived by Trace700 Compared to a 350 ton chiller, Thermal Storage plus a 190 ton chiller yields $15,000 in annual savings Much of the savings comes from the winter months, when they benefit from reduced PJM ratchet costs
The Demand Charge Effect ComEd Very Large Load Delivery Class, Secondary Energy (usage): Day: $0.045/kWh $0.116/kWh Night: $0.045/kWh $0.045/kWh Demand: $11.70/kW/Month How big an effect is the Demand Charge?? Energy is 61% less expensive at night
Demand Charge Effect.. Do the Math (Back of the Envelope) Conventional Chiller System Demand Cost /month 1000 tons x 0.8 kw/ton = 800kW 800 kw x $11.70 = $9,360/month Energy Usage for Chiller for Month 1000 tons x 10 Hrs x 75% x 0.8 kw/ton x 22 days/month = 132,000 kwh Approximate Cost for Demand / kwh $9,360/132,000 kwh/month = $0.071/kWh Therefore Daytime Energy = 4.5 cents + 7.1 cents = 11.6 cents/kwh
The Role of Energy Storage Most typical buildings have a bell shaped load curve 2000 1800 1600 1400 kw 1200 1000 800 600 400 200 0 [CATEGOR Y NAME]Chill Pumps er Fans Lighting Base Load Peak Load 1500 kw
The Role of Energy Storage Storage flattens out the peak and reduces demand charges 2000 kw 1800 1600 1400 1200 1000 800 600 400 200 0 Ice-Making [CATEGO RY NAME]Ice Chiller Pumps Cooling Fans Lighting Base Load Ice Peak Load 1200 kw Across the U.S., ice storage is all about reducing demand charges In Chicago, shaving 300kW would save over $30,000 per year.
Daytime Nighttime $ 2.50/gallon $ 0.99/gallon When Would you Fill-up?
Questions? Feel free to reach out to me: eberger@calmac.com 20