Vehicle to Grid Power Workshop at IEEE Conference Plug-In Hybrids: Accelerating Progress Washington, DC, September 19, 2007 Willett Kempton College of Marine and Earth Studies University of Delaware
Four Big Problems Global climate change. Evidence in the past two years suggest far more risk than before. Peak oil production; demand from China and India soaring; $200B/year in Middle East wars. US economy extraordinarily vulnerable to external supply and distant politics. Renewable energy plentiful at competitive prices, limited by intermittent supply.
Multiple Solutions with Plug-in cars + V2G It may be easier to solve multiple problems at once than one at a time. Plug-in cars -- batteries are now here Wind power: plentiful but intermittent Energy storage in gas tank -> in battery The car becomes new storage on the grid
Wind Resources of US Mid-Atlantic m Excl GW 0-20.46 60 20-50.40 117 50-100.10 153 Total 330 End-use Elec. load 73 GWavg Lt. veh 35
Rethinking the basics There will be lots of no-co2 electricity at per kwh (energy) prices lower than today, especially off-peak Electricity storage or backup (e.g. ancillary services markets) will be in much greater demand than today (but hopefully also cheaper per MW-h) How can we use lots of cheap electricity at times dictated by the grid operator (ISO or TSO)?
Plug-in Vehicles available now From an electrical standpoint, ideal car would have: battery 20-30 kwh, plug 15+ kw (240 V, 80 A). Two cars meet this and are in (limited) production: AC Propulsion ebox, an urban utility vehicle, also a sedan based on Yaris -- now handassembled (has V2G) Tesla Roadster, being produced by Lotus for Tesla (working on G2V or intelligent charging ) Hybrids can be used for V2G but are generally lower power (1.5 kw), different business model
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Tesla Roadster Burn Rubber, not Gasoline
An Unexpected Synergy Intermittent renewable energy and electricity as carrier for vehicles No new transportation or fuel infrastructure needed Smart interaction between vehicle fleet, grid and intermittent renewables Very large, low-cost storage for renewables Vehicle to Grid power ( V2G ) as a bridging technology.
Vehicle to Grid Arrows indicate direction of power flow
Regulation from hydro
Regulation from V2G (drive, charge & A/S)
V2G Basic Math Average car driven 1 hour/day --> time parked is 23 hours/day Daily average travel: 32 miles Practical power draw from car: 10-20 kw US power generation=811 GW; load=417 GW US 191 million cars x 15 kw = 2,865 GW
Calculating V2G power V2G power is the lowest of 3 factors: Wiring & plug at parking location, prepare for mass markets by assuming residential, say, 240VAC @ 80A 20 kw Internal Power Electronics to motor (typical 100 kw) Stored energy time Note: our equations are general to all: battery, hybrid/batt, hybrid/moto-gen, FC
How Much Power? Denmark UK USA Avg. Electric Load (GW) Light vehicles (10 6 ) Vehicle GW (if electric drive @ 15 kw each) 3.6 40 417 1.9 28.5 191 29 427 2,865
How Much Power? Denmark UK USA Avg. Electric Load (GW) Light vehicles (10 6 ) Vehicle GW (if electric drive @ 15 kw each) 3.6 40 417 1.9 28.5 191 29 427 2,865... power in cars >> generation or load
Effect of EVs with V2G on Grid Infrastructure Requirements 50% of cars as EVs increase electric load? 100 Million cars x 15,000 Miles per year / 4.8 Miles per kwh = 312 Billion kwh per year at off-peak times = 7 % of 2020 total national load With V2G, these EVs also provide a huge power resource: 100 M cars * 15 kw * 0.5 avail. = 750 GW of DG > 70% of 2020 national electric power capacity! Conclusion: Even 50% of cars as EV, IF they have V2G, probably REDUCE grid infrastructure requirements (Using back of the envelope method from W. Short, NREL, 2005) From Tomic & Kempton, 2005
Transition Strategy Business model demonstration: sets of 100+ cars Reassembly vs. OEM Start simple: Battery now, e-hybrid later Now building the Mid-Atlantic Grid- Interactive Car (MAGIC) Coalition...
A/S Regulation: Fleet operator as IPP 100 vehicles, parked 18h/d (16 h * 5 days + 24 h * 2 days), 80% available, each 20 kw A/S regulation services at $38/MW-h. Single connection point, single meter, 2 MW peak generator --> higher ISO comfort Revenue: 100*18h*365d*.8*.02MW*$38= $400,000/year revenue from fleet ($4,000/car/year)
Transition Strategy Small fleets: 100 car V2G fleet = 1 MW; demonstrate V2G business models Production in several regions, develop technology, drive down component costs Develop standards for V2G (e.g. response time, metering, at least 10 kw/car, drawdown limits, etc) THEN we need the OEMs, low-cost production at > 50,000 cars/year
But, don t we need to wait for the big OEMs?
OEMs won t start V2G change Expertise in combustion, mechanical engineering, low-cost mass production; engine as the primary value added (other components are commodity items) No expertise or IP in electrochemistry, power electronics, power markets Consumer s performance space inviolable Next step needed is power-plant size demonstration, need 100-500 vehicles; OEMs cannot do this efficiently or cheaply
BEV and PHEV Logic Non-fossil carriers essential to the future Hydrogen unlikely, especially in the near term, thus electricity primary carrier CO2 displacement by electricity large only if non-co2 generation (e.g. hydro or wind) Electricity as carrier goes directly to V2G logic...
V2G Logic Cars: A power resource too large to ignore V2G makes electric power capacity cheap, but electric energy is still expensive Today, market value for grid management Future, enable very large renewable energy Optimize design for both transport and electric system -- OEMs will not do this
Vision One-half vehicle fleet is electric drive: battery plus plug-in hybrid One-half of electric energy from wind, eventually other renewables Climate change is greatly slowed down; US can survive (a while) without foreign oil CO2-free electricity, high-penetration intermittent renewables, and CO2-free transportation: an unexpected and dramatic synergy
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