A CONCEPTUAL FRAMEWORK DESIGN FOR IMPLEMENTATION OF VEHICLE–TO–GRID (V2G) George Gross Department of Electrical & Computer Engineering University of Illinois at Urbana-Champaign ECE Seminar Series Carnegie Ca eg e Mellon e o U University e s ty November 12, 2009 © 2009 George Gross, All Rights Reserved. 1 MOTIVATION There are growing concerns around the world about energy independence and global warming issues The success of the Toyota Prius – with over 510,000 sold by November 2007 in the US – is a major driver in spearheading the development of battery vehicles (BVs) in the U.S. and Europe © 2009 George Gross, All Rights Reserved. 2 OUTLINE Integration of BVs into the electricity grid BVs as a load BVs as a g generation/storage g device role of aggregation Development of a conceptual framework © 2009 George Gross, All Rights Reserved. 3 OUTLINE Major implementational issues design of an incentive program metering and communication/control needs Environmental E i t l aspects t Concluding remarks © 2009 George Gross, All Rights Reserved. 4 THE ELECTRICITY GRID Not all the MWhs are equal in terms of costs and prices The value of each MWh depends on the time of production/consumption The integration of BVs into the grid can fully exploit the opportunities to: buy when the price is low price is high g sell when the p provide additional services needed by the grid © 2009 George Gross, All Rights Reserved. 5 DEMAND AND LMP demaand (M MW) 17,000 16,000 15,000 14 000 14,000 13,000 12,000 11,000 Source: NE ISO 0 2 4 6 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 6 DEMAND AND LMP average 16,000 demand demaand (M MW) 17,000 15,000 14 000 14,000 13,000 12,000 11,000 Source: NE ISO 0 2 4 6 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 7 DEMAND AND LMP average 16,000 demand 120 15,000 100 demaand (M MW) 17,000 110 90 14 000 14,000 80 13,000 70 12,000 60 11,000 50 8 10 12 14 16 18 20 22 24 Source: NE ISO 0 2 4 6 price ($/MW Wh) 130 time of day © 2009 George Gross, All Rights Reserved. 8 DEMAND AND LMP average 16,000 demand 120 15,000 100 demaand (M MW) 17,000 110 90 14 000 14,000 80 13,000 average price 12,000 11,000 Source: NE ISO 0 2 4 6 70 price ($/MW Wh) 130 60 50 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 9 THE BV AS A “PURE LOAD” s.o.c. (%) 100 60 6 8 time of day 18 © 2009 George Gross, All Rights Reserved. 24 10 CHARGING THE BVs 40 looad (GW W) 36 load with 4 million PHEVs 32 28 California load without BVs 24 20 6 12 18 time of day 24 Source: Lucy Sanna, “Driving the solution, the plug-in hybrid vehicle,” EPRI journal, Fall 2005 © 2009 George Gross, All Rights Reserved. 6 11 LEVELING THE LOAD demaand (M MW) 17,000 16,000 15,000 14 000 14,000 13,000 12,000 11,000 Source: NE ISO 0 2 4 6 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 12 LEVELING THE LOAD loadd impacts of the BVs 0 time of day © 2009 George Gross, All Rights Reserved. 5 13 REGULATION SERVICE AND PRICING 1200 demaand (M MW) 960 720 480 240 0 - 240 - 480 - 720 - 960 - 1200 Source: PJM 0 2 4 6 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 14 1200 80 960 70 720 60 480 240 50 0 40 - 240 30 - 480 20 - 720 10 - 960 - 1200 Source: PJM price ($/MW W/h) demaand (M MW) REGULATION SERVICE AND PRICING 0 2 4 6 0 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 15 REGULATION SERVICE AND PRICING average price demaand (M MW) 960 720 70 60 480 240 50 0 40 - 240 30 - 480 20 - 720 10 - 960 - 1200 Source: PJM 80 price ($/MW W/h) 1200 0 2 4 6 0 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 16 ROLE OF BVs IN FREQUENCY REGULATION A basic objective of the system operator is to ensure that the supply – demand equilibrium is maintained around the clock Imbalances lead to frequency fluctuations that need eed to be regulated egu ated The supply-demand imbalance is checked every 2 to 4 s © 2009 George Gross, All Rights Reserved. 17 ROLE OF BVs IN FREQUENCY REGULATION loadd/generration generation load time of day © 2009 George Gross, All Rights Reserved. 18 OFF – PEAK REGULATION Compliance with the unit commitment schedules becomes difficult during low load conditions that characterize the off – peak periods While, the operator may not wish to turn off units, there may be no choice Wind integration further exacerbates these conditions g prices p are,, typically, yp y, the highest g as The regulation many units need to reduce their outputs © 2009 George Gross, All Rights Reserved. 19 pricees > 2550 $/M MW/h num mber off days w with PEAK AND OFF – PEAK REGULATION time of day Source: CAISO © 2009 George Gross, All Rights Reserved. 20 BVs AND FREQUENCY REGULATION Batteries have the ability to both absorb and discharge energy The regulation capacity quantity provided by a battery is relatively small Batteries have very short response times (of the order of ms)) The frequent switching of batteries may, however, severely impact their life expectancies © 2009 George Gross, All Rights Reserved. 21 THE BV AS A “SUPPLY-SIDE RESOURCE” s.o.c. (%) 100 60 6 8 time of day 18 © 2009 George Gross, All Rights Reserved. 24 22 BATTERY ISSUES The battery capacity of each BV is small in terms of kWh storage This Thi capacity it limitation li it ti restricts t i t consequently tl the th “supply-side supply-side resource resource” capability of each BV A key y requirement for g grid integration g is the aggregation of BVs into a collection with capability to impact the grid © 2009 George Gross, All Rights Reserved. 23 V2G CONCEPTUAL FRAMEWORK Load aggregation Resource aggregation Explicit representation of uncertainty Communications/control layer construction Development of incentives © 2009 George Gross, All Rights Reserved. 24 PRINCIPAL PLAYERS IN THE V2G INTEGRATION BV Aggregator Aggregated gg g BVs ESP ISO/RTO © 2009 George Gross, All Rights Reserved. 25 THE INTEGRATION FRAMEWORK aggregator … … … resource aggregation load aggregation ESP © 2009 George Gross, All Rights Reserved. ISO/RTO 26 THE ROLE OF AGGREGATION The storage capacity C for a typical BV is in the 1 – 30 kWh range If we consider the total discharge of the full battery over 5 h, the output is in the 0.2 – 6 kW range The aggregator, who gathers together “many” BVs to result in a nontrivial aggregated output pp y and load, interfaces with the ISO/RTO on supplyside issues and the ESP on demand-side issues © 2009 George Gross, All Rights Reserved. 27 FLOWS IN V2G INTEGRATION individual BV owner ESP ISO/RTO 6 … … aggregated BVs as a resource parking facility battery supplier aggregated BVs as a load capacity/energy flows dollar flows © 2009 George Gross, All Rights Reserved. 28 V2G CONCEPTUAL FRAMEWORK all services $ 6 aggregated BVs as a resource BV … $ aggregated BVs as a load BV … BV MWh $ MW BV MWh $ MWh h ESP 1 ISO/RTO … ESP n parking services batteries $ battery supplier A … battery supplier Z $ parking facility D © 2009 George Gross, All Rights Reserved. … parking facility ] 29 REPRESENTATION OF UNCERTAINTY SOURCES We take into account various sources of uncertainty, including: time of arrival parking time state of charge storage of the vehicle demand For the aggregated BVs, BVs we use the Central Limit Theorem (N > 30) to justify the representation of th various the i random d variables i bl by b normall distributions © 2009 George Gross, All Rights Reserved. 30 DAILY COMMUTE DISTANCES 100 cumulativee percen ntage of veh hicles 90 80 70 60 50 40 average commute distance is 22 miles = 35 km 30 20 10 0 30 60 90 120 150 average daily travel distance (miles) Source: Lucy Sanna,“Driving the solution, the plug-in hybrid vehicle,” EPRI journal, Fall 2005 © 2009 George Gross, All Rights Reserved. 31 PARKING LOT UTILIZATION AS A FRACTION OF ITS CAPACITY 1 frraction 0.8 day 1 0.6 0.4 0.2 0 6 8 10 12 14 time of day 16 © 2009 George Gross, All Rights Reserved. 18 20 32 PARKING LOT UTILIZATION AS A FRACTION OF ITS CAPACITY 1 day 2 frraction 0.8 day 1 0.6 0.4 0.2 0 6 8 10 12 14 time of day 16 © 2009 George Gross, All Rights Reserved. 18 20 33 PARKING LOT UTILIZATION AS A FRACTION OF ITS CAPACITY day 3 day 2 day 4 1 frraction 0.8 day 1 0.6 0.4 0.2 0 6 8 10 12 14 16 18 20 time of day © 2009 George Gross, All Rights Reserved. 34 APPROXIMATION OF PARKING UTILIZATION 1 fr fraction 0.8 0.6 0.4 normal approximation 0.2 0 6 8 10 12 14 16 18 20 time of day © 2009 George Gross, All Rights Reserved. 35 MODEL OF PARKING UTILIZATION 1 fr fraction 0 .8 0 .6 0 .4 normal approximation 0 .2 0 6 8 10 12 14 16 18 20 time of day © 2009 George Gross, All Rights Reserved. 36 s.o.c. OF THE BV BATTERY The role of the s.o.c. is key to the effective power output (kW) management of the C 5 aggregated BV 60 integration into the grid y is a function of battery its storage capability s.o.c. 100 The output of a BV acts as supply-side resource (%) C 5 BV acts as BV acts as either demand-side demand- or supplyresource side resource © 2009 George Gross, All Rights Reserved. 37 BVs PROVIDE IMPORTANT SERVICE The aggregated BVs constitute a very important supply-side resource to the grid presence of the BVs p provide the ISO/RTO with The p considerable flexibility in the scheduling of units As a result, the start-up of cycling and peaking units may be delayed or avoided; the availability of reserves is improved and, during off-peak, the need for reserves is reduced © 2009 George Gross, All Rights Reserved. 38 CYCLING UNITS WITHOUT V2G peaking units demaand (M MW) 17,000 16,000 15,000 cycling i units start-up the cycling units 14 000 14,000 13,000 12,000 11,000 Source: NE ISO 0 2 4 6 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 39 CYCLING UNITS WITH V2G peaking units demaand (M MW) 17,000 16,000 15,000 cycling units i start-up the cycling units 14 000 14,000 13,000 12,000 11,000 Source: NE ISO delay 0 2 4 6 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 40 AGGREGATED BV POWER/CAPACITY 450 400 poweer (MW W) 350 300 250 200 150 100 50 0 5 10 15 time of day © 2009 George Gross, All Rights Reserved. 20 41 REGULATION SERVICE AND PRICING average price demaand (M MW) 960 720 70 60 480 240 50 0 40 - 240 30 - 480 20 - 720 10 - 960 - 1200 Source: PJM 80 price ($/MW W/h) 1200 0 2 4 6 0 8 10 12 14 16 18 20 22 24 time of day © 2009 George Gross, All Rights Reserved. 42 DAY – TIME REGULATION SERVICE PROVISION BY 100,000 , BVs 40 regulatioon (MW) 30 20 time of day 10 0 -10 8 10 12 14 16 18 -20 -30 -40 © 2009 George Gross, All Rights Reserved. 43 PERCENTAGE OF BVS PROVIDING THE REGULATION SERVICE perrcentage off BVs provid iding servicce 10 9 8 7 6 5 4 3 2 1 0 8 9 10 11 12 13 14 15 16 17 18 time of day © 2009 George Gross, All Rights Reserved. 44 PROVISION OF LOAD SHAVING SERVICE IN ADDITION TO REGULATION The number of BVs providing regulation service remains rather low low, with fewer than 10% of the BVs in the aggregation providing service at each point in time We consider the provision of load shaving service in addition to the regulation service We show that the Aggregator can provide 100 MWh of load shaving service at a constant power output between 9:00 and 9:30 a.m for an aggregation of 100,000 BVs © 2009 George Gross, All Rights Reserved. 45 PERCENTAGE OF BVS PROVIDING LOAD SHAVING AND REGULATION SERVICE percen ntage of BV Vs providin ng service 60 50 40 30 20 10 0 8 9 10 11 12 13 14 time of day 15 © 2009 George Gross, All Rights Reserved. 16 17 18 46 maxim mum consttant powerr output fo or the 9--9:30 perio od in addiition to thee provvision of 3 30-MW reg egulation serviice (MW) ENERGY PROVIDED IN ADDITION TO THE REGULATION SERVICE 200 150 100 50 0 40 50 60 70 80 90 100 size of BV aggregation in thousands © 2009 George Gross, All Rights Reserved. 47 REGULATION FOR OFF-PEAK CONDITIONS r regulati ion (M MW) 1000 500 0 1 2 3 4 5 6 1 2 3 4 5 6 - 500 time of day - 10 00 0 © 2009 George Gross, All Rights Reserved. 48 REGULATION FOR OFF-PEAK CONDITIONS r regulati ion (M MW) 1000 500 0 1 2 3 4 5 6 2 3 4 5 6 - 500 - 10 00 time of day 10,000 BVs 0 1 © 2009 George Gross, All Rights Reserved. 49 REGULATION FOR OFF-PEAK CONDITIONS r regulati ion (M MW) 1000 500 0 1 2 3 4 5 6 - 500 - 10 00 10,000 BVs 0 1 time of day 50,000 BVs 2 3 4 © 2009 George Gross, All Rights Reserved. 5 6 50 REGULATION FOR OFF-PEAK CONDITIONS r regulati ion (M MW) 1000 100,000 BVs 500 0 1 2 3 4 5 6 - 500 - 10 00 10,000 BVs 0 1 time of day 50,000 BVs 2 3 4 © 2009 George Gross, All Rights Reserved. 5 6 51 REGULATION FOR OFF-PEAK CONDITIONS r regulati ion (M MW) 1000 100,000 BVs 500 500,000 BVs 0 - 500 - 10 00 10,000 BVs 0 1 50,000 BVs 2 3 4 time of day © 2009 George Gross, All Rights Reserved. 5 6 52 KEY IMPLEMENTATIONAL ISSUES Aggregation implementation Information layer construction Incentive development Realization of environmental benefits © 2009 George Gross, All Rights Reserved. 53 V2G COMMUNICATION AND METERING charging station stat o Aggregator 6 distribution ggrid . ZigBee i transceiver ISO/RTO ISO/RTO . ESP © 2009 George Gross, All Rights Reserved. 54 ESSENTIAL COMMUNICATION / CONTROL SYSTEM REQUIREMENTS Speed: signals need to be sent every 1 to 2 s Range: R every BV in i a parking ki lot l t mustt be b on the th communication network Measurement: metering must be installed to enable payment for services Reliability: full utilization of all parked aggregated BVs Security: BVs may be used to hack the network © 2009 George Gross, All Rights Reserved. 55 ESSENTIAL COMMUNICATION / CONTROL SYSTEM REQUIREMENTS Costs: each BV has an implanted device and the costs per unit must be low for the large collection of aggregated BVs Extendibility: the communication layer must allow g of additional BVs the integration Interoperability: a non-restrictive, flexible standard needs to be introduced and implemented © 2009 George Gross, All Rights Reserved. 56 COMPUTER / COMMUNICATION / CONTROL NETWORK: INFORMATION FLOWS ID of each BV Preferences/constraints of each BV Parking P ki status t t off each h BV Storage capability of the BV battery The BV battery s.o.c. Power flows from BV battery to the grid Measured value of metered quantities © 2009 George Gross, All Rights Reserved. 57 THE ROLES OF THE AGGREGATOR Development of the parking infrastructure Maintenance of the batteries and the network Creation of relationships with the BV manufacturers f t Interface with ISO/RTO © 2009 George Gross, All Rights Reserved. 58 VALUE ADDED BY THE AGGREGATOR Provides a “package deal” to the aggregated BVs in terms of: parking facilities service i acquisition i iti and d provision i i charging of BVs battery service p shopping” pp g for potential p BV Allows “one-stop participants Acts as a provider of environmental benefits for reduced emissions © 2009 George Gross, All Rights Reserved. 59 NET GENERATION BY ENERGY SOURCE UP TO 6/31/2009 petroleum 1.15 1.15% % nuclear 20.8% hydro 7.6 7.6% % natural gas 21.4% 21 4% 21.4 4% other renewable 3.6% 3.6 % coal 45% other th gases 0.5% 0 5% 0.5 5% industry total = 4,115 Twh Source : Ameren IP © 2009 George Gross, All Rights Reserved. 60 CO2 EMISSION BY PLANT TYPE 1000 900 800 600 500 400 300 200 100 © 2009 George Gross, All Rights Reserved. co al na tu ra lg as pe tr ol eu m so la r nu cl ea r hy dr o 0 w in d g/kWh h 700 61 ENERGY CONSUMPTION UNDER MIXED CONDITIONS 0,30 . kW Wh/km m 0,25 . 0,20 . 0,15 . 0,10 . 0,05 , . 0,00 Miles EV Volvo C30 Recharge Tesla roadster . © 2009 George Gross, All Rights Reserved. Chevrolet LUV (Chile 2000) . 62 VEHICLE CO2 EMISSIONS 350 300 g g/km 250 200 150 100 50 0 EV France EV Canada EV USA EV Germany © 2009 George Gross, All Rights Reserved. internal combustion 63 FUTURE WORK Improvement of the BV selection for the provision of higher energy and regulation performance Design and implementation of a secure and economic communication/control architecture Design of an effective incentive program for high BV participation and retention © 2009 George Gross, All Rights Reserved. 64 CONCLUDING REMARKS Integration of BVs helps the grid both as loads and as generation sources S sa and d ISO/RTOs SO/ Os will have a e a new e player p aye to do ESPs business with Aggregators are key for the implementation of V2G concept to be successful The BV aggregator has the potential for making sizeable benefits © 2009 George Gross, All Rights Reserved. 65 REFERENCES C. Guille and G. Gross, "A Conceptual Framework for the Vehicle-to-Grid (V2G) Implementation," accepted for publication in Energy Policy, 2009 © 2009 George Gross, All Rights Reserved. 66