0© 2013 Stem, Inc. 0Tacklingpeakdemandcharges
1© 2013 Stem, Inc. 1Agenda•Overview of peak demand charges•Future trends in demand charges•Traditional approaches•A new ap...
2© 2013 Stem, Inc. 2Agenda•Overview of peak demand charges•Future trends in demand charges•Traditional approaches•A new ap...
3© 2013 Stem, Inc. 3TwopartstoanenergybillEnergy charges Demand chargeTotal amount of energy used Highest 15-minute peak e...
4© 2013 Stem, Inc. 4Whatisademandcharge?•Monthly charge based on highest 15-min peak during that month•Typically 30–70% of...
5© 2013 Stem, Inc. 5Whoissubjecttodemandcharges?•Levied on certain commercial &industrial customersLargebusinesses…ontime-...
6© 2013 Stem, Inc. 6Whydodemandchargesexist?• Covers utilities fixed costs of providing a given level of power• “Hottestda...
7© 2013 Stem, Inc. 7Howdemandchargesarecalculated•Highestlevelofusageduringa15minuteperiodoutofanentirebillingcycle•Thatus...
8© 2013 Stem, Inc. 8DemandchargeworksheetWinterrate (e.g. Nov1 – Apr 30)Off peakPartialpeakOff peakPeak kWduring periodx _...
9© 2013 Stem, Inc. 9ImpactofdemandchargesCustomer A50 kW load for 50 hours:UsageEnergy = 50 kW x 50 hours = 2,500 kWhDeman...
10Energy charges (kWh) $11,998 50%Demand charges (kW) $10,802 45%Miscellaneous $1,322Total bill $24,123Demand charges aren...
11© 2013 Stem, Inc. 11Yourdemandcharge1.Links todemand charges for California utilities:PG&E (E-19) http://www.pge.com/tar...
12© 2013 Stem, Inc. 12Agenda•Overview of demand charges•Future trends in demand charges•Traditional approaches•A new appro...
13© 2013 Stem, Inc. 13ExpecteddemandchargeratechangesIncrease inPG&E rates inpast 3 years31%Source: Tariff data for Pacifi...
14© 2013 Stem, Inc. 14•Aging grid & peaker plants•Proliferation of solar leadingtogreater grid volatility•Growth in electr...
15© 2013 Stem, Inc. 15Agenda•Overview of demand charges•Future trends in demand charges•Traditional approaches•A new appro...
16© 2013 Stem, Inc. 16Short–term approachesLoadshifting / sheddingPerform energy-intensive operations when your facility’s...
17© 2013 Stem, Inc. 17Short–term approachesLoadcyclingControl when equipment runs. For instance, if you have six air-condi...
18© 2013 Stem, Inc. 18Short–term approachesInterlocks & automatic controlling devicesUse timers to pre-heat or pre-cool wa...
19© 2013 Stem, Inc. 19Short–term approachesTiming of projectsBe aware of when your meter is read each month. For example, ...
20© 2013 Stem, Inc. 20Long–term approaches• Energy efficiency measures• Updatinglighting• Insulationreplacement• Retro-com...
21© 2013 Stem, Inc. 21Long–term approaches• Right-sizing equipment• Air-conditioning systemsarethemostcommon over-sizedequ...
22© 2013 Stem, Inc. 22Long–term approaches• Equipment upgrades• Ensure equipment has motors that are theright size for the...
23© 2013 Stem, Inc. 23Agenda•Overview of demand charges•Future trends in demand charges•Traditional approaches•A new appro...
24• Reduce spikes without interfering with operations• Work in parallel with other energy efficiency measures• Require no ...
25© 2013 Stem, Inc. 25Combine battery storage andbig data analytics to reduce energy costsAdvanced storage solutions
26How they work• Predict building’s energy usage• Charge on-site battery during off-peak• Anticipate peak events and relea...
27ResultsReduced demand charges: lower energy bills automaticallyReduced risk: eliminates the need to constantly monitoren...
28© 2013 Stem, Inc. 28For more information on advanced storagesolutions to tackle peak demand charges, visit:stem.com
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Electricity peak demand charges overview

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Electricity peak demand charges overview

  1. 1. 0© 2013 Stem, Inc. 0Tacklingpeakdemandcharges
  2. 2. 1© 2013 Stem, Inc. 1Agenda•Overview of peak demand charges•Future trends in demand charges•Traditional approaches•A new approach
  3. 3. 2© 2013 Stem, Inc. 2Agenda•Overview of peak demand charges•Future trends in demand charges•Traditional approaches•A new approach
  4. 4. 3© 2013 Stem, Inc. 3TwopartstoanenergybillEnergy charges Demand chargeTotal amount of energy used Highest 15-minute peak each monthDemand chargeEnergy charges
  5. 5. 4© 2013 Stem, Inc. 4Whatisademandcharge?•Monthly charge based on highest 15-min peak during that month•Typically 30–70% of total electric bill•Usually differs by season (typically higher in summer than winter)
  6. 6. 5© 2013 Stem, Inc. 5Whoissubjecttodemandcharges?•Levied on certain commercial &industrial customersLargebusinesses…ontime-of-usebills…withenergyusageexceedingacertainlevel(e.g.2000kWh/month)•All states have demand charges, but at varying levels
  7. 7. 6© 2013 Stem, Inc. 6Whydodemandchargesexist?• Covers utilities fixed costs of providing a given level of power• “Hottestday in July” scenariowhere utilities have to have enough capacityon standbyto supplyALLcustomerswith heavy HVAC loads• Used by utilities to reduce peak by making it desirable to:• shiftelectricalusage from peak hours to non-peakhours• reducepower usage during peak hours• Levies higher costs on customers with spikier loads• Passessavings on to other customerswith more consistentloads
  8. 8. 7© 2013 Stem, Inc. 7Howdemandchargesarecalculated•Highestlevelofusageduringa15minuteperiodoutofanentirebillingcycle•Thatusage,measuredinkW,isthenmultipliedbythedemandchargerateSpeedometer – highestOdometer – accumulatedAuto AnalogyAnalogous to demand chargeAnalogous to energy charge
  9. 9. 8© 2013 Stem, Inc. 8DemandchargeworksheetWinterrate (e.g. Nov1 – Apr 30)Off peakPartialpeakOff peakPeak kWduring periodx ______ rateWinter peak demand chargesPeak kWany timex ______ rate+ =Maximum demandSummerrate (e.g. May 1 – Oct 30)Maximum demandOffpeakOffpeakPeak kWduring periodSummer peak demand chargesPeak kWany timex ______ rate+ =Maxpeakx _____ x_____+PartialpeakPartialpeakInstructions for each season:1. Fill in boxes with peak kW for each peak period andmaximum demand for the month.2. Fill in blanks with peak kW rates from utility.3. Multiple 1 and 2 to get charges for each peak period.4. Add up charges for total for the season.1234
  10. 10. 9© 2013 Stem, Inc. 9ImpactofdemandchargesCustomer A50 kW load for 50 hours:UsageEnergy = 50 kW x 50 hours = 2,500 kWhDemand = 50 kWBillEnergy= 2,500 kWh x $0.15 = $ 375.00Demand = 50 kW x $28.00 = $1,400.00Total= $1,775.00Customer B5 kW load for 500 hours:UsageEnergy = 5 kW x 500 hours = 2,500 kWhDemand = 5 kWBillEnergy= 2,500 kWh x $0.15 = $ 375.00Demand = 5 kW x $28.00 = $ 140.00Total= $515.00Identical energy usage, but very different totals due to PATTERN of energy usage
  11. 11. 10Energy charges (kWh) $11,998 50%Demand charges (kW) $10,802 45%Miscellaneous $1,322Total bill $24,123Demand charges aren’t always obviousAfter adding these up, you find…Energy vs. Demand charges… and realize the demand charges arenearly 50% of your electricity bill
  12. 12. 11© 2013 Stem, Inc. 11Yourdemandcharge1.Links todemand charges for California utilities:PG&E (E-19) http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-19.pdfSDG&E (AL-TOU) http://www2.sdge.com/tariff/com-elec/ALTOUPrimary.pdfSCE (GS-2) https://www.sce.com/wps/portal/home/regulatory/tariff-books/rates-pricing-choices/business-rates/2.Contact your utility account managerThey are there tohelp you understand your rate schedules
  13. 13. 12© 2013 Stem, Inc. 12Agenda•Overview of demand charges•Future trends in demand charges•Traditional approaches•A new approach
  14. 14. 13© 2013 Stem, Inc. 13ExpecteddemandchargeratechangesIncrease inPG&E rates inpast 3 years31%Source: Tariff data for Pacific Gas and Electric, San Diego Gas and Electric, and Southern California Edison is publiclyavailable via utility websites3-year growth rate (2010-2013) 31% 22% 9% 19.5%Average Demand Charges in CA ($/kW)$16.64$18.74$17.74 $17.88$21.83$22.92$19.34$21.36$0.00$5.00$10.00$15.00$20.00$25.00PG&E E-19 SDG&E AL-TOU SCE GS-2 TOU Option B CA IOU average20102013
  15. 15. 14© 2013 Stem, Inc. 14•Aging grid & peaker plants•Proliferation of solar leadingtogreater grid volatility•Growth in electric vehiclecharging stations•Climate changeWhythistrend?
  16. 16. 15© 2013 Stem, Inc. 15Agenda•Overview of demand charges•Future trends in demand charges•Traditional approaches•A new approach
  17. 17. 16© 2013 Stem, Inc. 16Short–term approachesLoadshifting / sheddingPerform energy-intensive operations when your facility’s demand islow. For example, run large equipment at night or early in themorning instead of the middle of the day.PeakOff-peak Off-peak
  18. 18. 17© 2013 Stem, Inc. 17Short–term approachesLoadcyclingControl when equipment runs. For instance, if you have six air-conditioning compressors, you can install a system that allows onlythree or four units to operate simultaneously. The buildings air handlerswill continue to circulate air and ensure a healthy environment.HVAC 1 HVAC 3HVAC 2PeakOff-peak Off-peakHVAC 2HVAC 3
  19. 19. 18© 2013 Stem, Inc. 18Short–term approachesInterlocks & automatic controlling devicesUse timers to pre-heat or pre-cool water and air during off-peak times.Some utilities will install equipment that interrupts nonessential loads atyour facility for a specified amount of time in exchange for lower rates.PeakOff-peak Off-peak
  20. 20. 19© 2013 Stem, Inc. 19Short–term approachesTiming of projectsBe aware of when your meter is read each month. For example, if youhave a project that will take a lot of energy, run that project during abilling month when you’ve already incurred a high demand charge.Month 1 Month 2MeterreadingPeakPeak
  21. 21. 20© 2013 Stem, Inc. 20Long–term approaches• Energy efficiency measures• Updatinglighting• Insulationreplacement• Retro-commissioning equipment
  22. 22. 21© 2013 Stem, Inc. 21Long–term approaches• Right-sizing equipment• Air-conditioning systemsarethemostcommon over-sizedequipment• LightingretrofitsshouldbedonebeforeACunitsaredownsized• modernlightingwillreducecoolingrequirements
  23. 23. 22© 2013 Stem, Inc. 22Long–term approaches• Equipment upgrades• Ensure equipment has motors that are theright size for their corresponding pumps• Newer, more efficient pump and motorcombinations may save on demand charges
  24. 24. 23© 2013 Stem, Inc. 23Agenda•Overview of demand charges•Future trends in demand charges•Traditional approaches•A new approach
  25. 25. 24• Reduce spikes without interfering with operations• Work in parallel with other energy efficiency measures• Require no behavioral changes or trainingThe ideal solution would …
  26. 26. 25© 2013 Stem, Inc. 25Combine battery storage andbig data analytics to reduce energy costsAdvanced storage solutions
  27. 27. 26How they work• Predict building’s energy usage• Charge on-site battery during off-peak• Anticipate peak events and release stored energyMax demand without storageMax demand with storage
  28. 28. 27ResultsReduced demand charges: lower energy bills automaticallyReduced risk: eliminates the need to constantly monitorenergy usageFuture-proofing: allows businesses to hedge against futureenergy price changesCarbon savings: displaces peaker plant capacity by reducingpeak loads
  29. 29. 28© 2013 Stem, Inc. 28For more information on advanced storagesolutions to tackle peak demand charges, visit:stem.com

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