Prius PHEV Will Have V2G Capability

A new plug-in hybrid electric vehicle, capable of 125 mpg and receiving electricity from or sending it to the grid, has been acquired by the Colorado Governor's Office of Energy Management and Conservation (OEMC) as part of a NREL program. HybridsPlus, Inc. converted a 2006 Toyota Prius into a plug-in hybrid electric vehicle (PHEV) for demonstration purposes.

HybridsPlus, based in Boulder, Colorado, is the newest company offering to convert Priuses to plug-in hybrid vehicles (PHEV).

A Plug-in Hybrid car can be fueled by electricity from an electrical outlet or by gasoline. Initially, a PHEV uses less gas than an hybrid electric vehicle (HEV), because it can draw energy longer, from its larger battery. For example, a Toyota Prius' 50 mpg efficiency can be improved to about 100 mpg when operated as a PHEV. Eventually, when that storage of electrical energy is depleted, a PHEV is no more efficient than an HEV.

Presently, the only practical way to get a PHEV is to convert a production HEV. This entails:

• adding a charger and a power cord
• replacing the original battery control unit with a new one
• increasing the electrical storage capacity of the batteries

The primary advantage of converting to a PHEV is for better mileage, less oil consumption, and lower driving costs. Additionally, PHEVs can be driven strictly as an electric vehicle during in-town driving or at speeds less than 35 mph, offering another fuel saving feature along with lower tailpipe emissions.

The HybridPlus PHEV-15, 15 mile range, conversions retain the original storage space and spare tire location so that the conversion is next to invisible to the user, except of course for the extended mileage. The PHEV-30 has a 30 mile range and have a small reduction in storage space.  They use Li-Ion cells from A123: they are leak-proof and flame-proof, (theoretically they could be charged in 15 minutes if sufficient power were available). To charge the battery, simply plug the power cord in any 120 Vac outlet. A fully discharged PHEV-30 battery will take about 9 hours to charge. Assembly of a PHEV-15 battery pack is shown in the picture.

Their is more detailed technical information on the A123 batteries used in the PHEV available here, more than I have seen before. They are 25 mm (1 inch) diameter by 65 mm long cylindrical cells with 2.3 Ah capacity at 3.3 V with a cell life of over 1000 cycles at 100% DOD.

The following is from HybridsPlus's excellent FAQ:

How far can you go on a charge?

For a Prius PHEV-30, the quick answer is:

• • Driving slower than 34 mph: about 30 miles in Pure Electric Mode
  • Driving up to highway speeds: about 60 miles in Mixed Mode (gasoline + electricity), with about 100 mpg efficiency
• For a Prius PHEV-15, the distance will be about 15 miles on Pure Electric Mode, about 30 miles in Mixed Mode.
• After the battery is discharged, you still get the original 50 mpg efficiency of the Prius.
• The assumption is that you will drive conservatively, and you start from a fully charged battery.

What is the cost of conversion?

Presently, the cost of a conversion, done by Hybrids Plus, in Boulder, CO, is:

• $ 24,000 for the PHEV-15
• $ 32,500 for the PHEV-30

Most of this is to cover the cost of the high quality, A123, Li-ion cells. This price does not include transportation of a vehicle to and from Boulder.

They expect the prices to drop about $4,000 in early 2007 and battery, prices which are the largest part of the cost, to drop by 15% per year. More pricing data is available on their products page.

How can you justify $ 32,500 for a conversion?

Today, people convert HEVs to PHEV for environmental and political reasons, and to be a pioneer in the PHEV field. They don't do it for personal economic reasons: today's conversion price is such that its cost cannot be recovered through fuel savings alone.
Early adopters of this technology make its development possible, and in the process, help drive the price of conversions down to a more reasonable level.

What is V2G capability?

This Prius will also soon have Vehicle to Grid (V2G) capability, which means it can provide power to as well as receive power from the electrical grid.

Electric-drive vehicles, whether powered by batteries, fuel cells, or gasoline hybrids, have within them the energy source and power electronics capable of producing the 60 Hz AC electricity that powers our homes and offices. Cars pack a lot of power. One typical electric-drive vehicle can put out over 10kW, the average draw of 10 houses. The key to realizing economic value from V2G is precise timing of its grid power production to fit within driving requirements while meeting the time-critical power "dispatch" of the electric distribution system.

Vehicles could generate plenty of power - studies show they sit idle 90 percent of the time. V2G appears to be unsuitable for baseload power—the constant round-the clock electricity supply—because baseload power can be provided more cheaply by large generators, as it is today. Rather, V2G’s greatest near-term promise is for quick-response, high-value electric services for which utilities pay premium prices. These quick-response electric services are purchased to balance constant fluctuations in load and to adapt to unexpected equipment failures; they account for 5–10% of electric cost—$ 12 billion per year in the US.

The engineering rationale and economic motivation for V2G power are compelling. The societal advantages of developing V2G include an additional revenue stream for cleaner vehicles, increased stability and reliability of the electric grid, lower electric system costs, and eventually, inexpensive storage and backup for renewable electricity.

The basic concept of vehicle-to-grid power is that EDVs provide power to the grid while parked. Battery EDVs can charge during low demand times and discharge when power is needed. Fuel cell EDVs generate power from liquid or gaseous fuel. Plug-in hybrid EDVs can function in either mode.

The areas where V2G vehicles could benefit the electrical grid the most are spinning reserves and regulation, which must deliver power within minutes or seconds of a request.

Spinning reserves refers to additional generating capacity that can provide power quickly, say within 10 min, upon request from the grid operator. Generators providing spinning reserves run at low or partial speed and thus are already synchronized to the grid. Studies show.It would be far cheaper for utilities to tap the batteries of thousands of cars than the current practice of keeping huge turbines constantly spinning just to supply power at a moment's notice,

Regulation, is used to fine-tune the frequency and voltage of the grid by matching generation to load demand. Regulation must be under direct real-time control of the grid operator, with the generating unit capable of receiving signals from the grid operator’s computer and responding within a minute or less by increasing or decreasing the output of the generator.

if automakers were to make 1 million next-generation V2G vehicles by 2020, they could generate up to 10,000 megawatts of electricity - about the capacity of 20 average-size power plants, according to a 2001 study by AC Propulsion.

And there would be little risk of leaving the office to discover a car with a dead battery. That's because V2G cars would have on-board controls to prevent their batteries from being drawn below a minimum value determined by the vehicle owner.

V2G information was taken from various sources referenced on the AC Propulsion V2G Technology page.

Comments

[donb]

The biggest problem I see with the V2G concept is that the most likely time for the grid needing an assist is late afternoon on a hot day. In this case, the driver would begin the commute home only to find the battery discharged. Depending on the control algorithm, the car might start charging the battery using the gasoline motor, wiping out the gas savings from the morning.

[Thomas]

Early adoption costs! That goes for PHEVs as well as plasma TVs, blu-ray or whatever.

V2G is a very important feature of battery powered vehicles, be it BEVs or PHEVs. That feature will become increasingly important in the future if more renewable energy sources are tapped. The two form a near-perfect symbiosys.

[Roderick Williams]

Assuming the cars are being used as storage capacity for renewables, wouldn't the cars be charging throughout the day from PVs and then discharging to run aircon in the afternoon. Provided the car has sufficient storage capacity I wouldn't care if its half or 2/3s full for a normal commute.

[amazingdrx]

Excellent! 100s of millions of grid connected vehicles, at work, at home, even at a shopping center would store a lot of energy. The actual percentage of drive time compared to the time most vehicles just sit in one spot is very small. Maybe 5% of an average car's life is spent on the road?

As far as charge problems where peak demand conflicts with peak driving time, with a quick charge time vehicles can go from 20% charge to 90% very quickly when one needs to use them.

And peak air conditioning demand, for instance, coincides with peak solar power, so that would not be a problem given solar electric on every possible roof, especially those roofs in hot sunny regions that need the most air conditioning.

Anyway a peak demand might actually only deplete the average electric pligin car battery maybe 20%? That wouldn't be a problem, that 20% could be replenished in a few minutes.

Why not adjust working hours to cure traffic jams too? It would smooth out peak power demand for driving too.

And if drivers schedule their commute time into the onboard charging controller no convenience is lost and in fact utility company charging and storage systems can read this vehicle programing and adjust for it.

Switching to universal wireless broadband internet transmitted over the grid would facilitate this, as well as increasing productivity by eliminating the need for regular phone, cable, and cellular phone systems.

This upgrade of information technology would save enough money to pay for most of the power grid upgrade that is needed. Think of all the duplication waste eliminated!

Broadband over the utility grid can carry all information now carried by expensive cable tv, phone, cellular phone and internet systems.

Put these monopolists all on an even playing field over the utility grid and watch cable tv, internet, and phone prices drop with real competition.

[Trailblazer]

To replace 20 power plants is worth the effort right there. If we allow those plants (currently nuclear plants are planned) to be built instead, we'll end up with nothing that is sustainable.

This is so cool and such a good idea. But then, I'm preaching to the choir here, I'm sure.

[Jonathan Fry]

Anyone else see the potential for a car virus? It may be possible for these networked cars to get a virus. Someone could make a virus to infect the cars so they will charge (drain power) from the grid during a peak time. This could be used to bring the grid down if they rely only on them for peak demand.

[SJ]

Just wanted to share this interesting energy calculation workbook I found online It is cool. It actually shows you how to measure the amount of energy that your car really needs!! (as opposed to how much gas it eats). It also shows you how to measure the difference of energy used at low speeds and high speeds, lets you calculate the engine’s energy efficiency, and how your car’s energy compares to other things like energy in your home. It also discusses wind and solar energy, vehicle to grid technology (V2G) as well as electric and hybrid cars.

www.howmuchenergydoesmycaruse.com

This link is also very interesting ...
www.themanhattanprojectof2009.com

[J Chen]

A complete 2KW Li-ion conversion kit is available under $2000
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200344551230

[Yuasa Batteries]

Nice post, well written. Where can i find more of your views?

[New Balance 574]

This post really had me thinking about this particular issue in way I havent before. Its something I do believe we need to talk about more. Thankyou.