Could Electric Cars Threaten the Grid?

[OKIsItJustMe]

http://www.technologyreview.com/news/518066/could-electric-cars-threaten-the-grid/

[font face=Serif][font size=5]Could Electric Cars Threaten the Grid?[/font]

[font size=4]Some neighborhood grids just aren’t built for huge spikes in power demand. The rise of the electric car has utilities scrambling to adjust.[/font]

By Kevin Bullis on August 16, 2013

[font size=3]Plugging in an electric vehicle is, in some cases, the equivalent of adding three houses to the grid. That has utilities in California—where the largest number of electric vehicles are sold—scrambling to upgrade the grid.

Electric cars being sold today can draw two to five times more power when they’re charging than electric cars that came on the market just a couple of years ago. Last year in the United States, only about 50,000 were sold. Researchers at the U.S. Department of Energy’s Pacific Northwest National Laboratory have calculated that the grid has enough excess capacity to support over 150 million battery-powered cars, or about 75 percent of the cars, pickups, and SUVs on the road in the United States. But there’s a catch. While power plants and transmission lines have excess capacity, things can get tight when it comes to distributing power to individual neighborhoods. And this is especially the case since electric vehicle sales aren’t evenly distributed. In California, for example, they’re taking off in Silicon Valley and places such as Long Beach and Santa Monica.

The impact of charging an electric car depends on where it is on the grid and how it is charged. They don’t pose a problem if they’re charged slowly at conventional 110 volt outlets. And public fast-charging stations don’t impact the grid much because they are part of commercial grids that have transformers and other equipment sized to accommodate large loads.

The trouble arises when electric car owners install dedicated electric vehicle charging circuits. In most parts of California, charging an electric car at one of those is the equivalent of adding one house to the grid, which can be a significant additional burden, since a typical neighborhood circuit has only five to 10 houses. In San Francisco, where the weather is cool and air conditioning is rarely used, the peak demand of a house is much lower than in the hotter parts of California. As a result, the local grid is sized for a much smaller load. A house in San Francisco might only draw two kilowatts of power at times of peak demand, according to Pacific Gas & Electric. In comparison, a new electric vehicle on a dedicated circuit could draw 6.6 kilowatts—and up to 20 kilowatts in the case of an optional home fast charger for a Tesla Model S.

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[global1]

1. I Smell An Excuse For Electric Companies To Raise Their Rates......nt

[FBaggins]

2. Maybe at first, but in the end they'll help the grid.

I'll let Kris weigh in on the V2G possibilities (substantial), but there's another benefit that's just as important.

We must get to a point where the grid of the future is "smarter". Too many people are charged by just the amount they use, ignoring when they use it (and how much it costs to produce it at that time). We can put temporary programs in place to influence consumption behaviors, but the holy grail of getting this to work is put the consumer into the market and give him access to the information needed to make the right choices.

We can, for instance, generate less overall (cheaper than any source) by leveling demand. Use that unused night capacity and lower the daytime peak... and you've improved the entire system.

Many electric cars would be charging overnight. If there are enough of them, utilities will be forced to support smarter meters and lower nighttime electricity prices.

Here's an NPR piece from today that does a better job
http://www.democraticunderground.com/112751845

[OKIsItJustMe]

3. I am a V2G skeptic

At least with current battery technology, V2G could have a significantly detrimental effect on battery lifespan.

Nissan (for example) warranties their battery for 100,000 miles. V2G cycles would lead to fewer driving cycles.

http://www.plugincars.com/eight-tips-extend-battery-life-your-electric-car-107938.html

[FBaggins]

4. Keep in mind that storage in such a grid can be very valuable

Value that can compensate the owner for a shorter battery life. Then battery designs would change as consumers used that flexibility as a differentiator in the marketplace.

But also keep in mind that the benefit to the grid isn't just storage. Just the flexibility to determine when within the cycle to send those kilowatt-hours to the battery could provide a solid benefit.

Lastly... I haven't looked at the design (and any chemical physics days are decades behind me anyway)... but I'm not sure that the impact would be so substantial. The battery goes through scores of mini drain/charge cycles every time you drive it. The type of storage (IMO - I'll let Kris weigh in) that they would be used for most frequently would also be pretty short/shallow cycles. Really flattening out short-term variability/fluctuations rather than substituting for longer-term grid-scale storage.

[OKIsItJustMe]

6. If car owners were paid for the service they provide to the grid…

…it might (in theory) pay for the battery degradation. (There have been studies which suggest this.)

Maybe it’s just me, but the idea of the power company knowing where I plug my car in, every time I plug my car in, so they can figure out how much they owe me for using my car’s battery for V2G while it was plugged in…

[kristopher]

9. Then don't participate

No one is going to force you.

It is going to be an automatic transaction, but if your paranoia is that bad perhaps you might want to let others do it. You might want to get rid of your cell phone while you're at it.

[FBaggins]

10. Exactly

Sometimes I use my personal car when I travel. It puts wear and tear on the vehicle and shortens the usable life for personal travel, but the mileage reimbursement exceeds my estimate of personal depreciation and fuel costs.

But I don't have to do it if I don't want to.

[kristopher]

5. Do you actually know how V2G uses a battery?

Battery life is largely determined by full discharge cycles.

How does V2G use a battery to augment the performance of the grid?

As planned for initial deployment, does it result in full discharge cycles?

[OKIsItJustMe]

7. The definition of V2G is somewhat nebulous

Yes, yes, this much we can say, it is (in one form) a controlled two-way flow of electricity between battery electric vehicles and the grid. However, there are multiple services which could potentially be provided to the grid, which have different effects on the BEV’s battery.

http://www1.eere.energy.gov/vehiclesandfuels/avta/pdfs/evse/v2g_power_flow_rpt.pdf

[font face=Serif][font size=5]Vehicle-to-Grid (V2G) Power Flow Regulations and Building Codes Review by the AVTA[/font]

[font size=3]…
1.3.1.2 Grid support. There are two main categories of grid support for which V2G might be useful. The first is providing peak power, because meeting the demands of peak power currently is a very expensive obligation for utilities. If vehicle ESSs could be charged during off-peak times and then discharged selectively to “shave the peak,” the utility could potentially forego the need to start up a peaking plant, which would save on operation and maintenance costs and yield significant environmental benefits. Peaking power plants are sometimes used only for several hours per year. Utilities have strong predictive capability for peak load planning (mostly during the summer due to air-conditioning load). The ability to activate distributed storage, along with traditional demand response (DR) assets, provides a cost-effective and clean alternative to expensive and capital-intensive spinning “peaking plant” generators. Therefore, the cost-benefit of a V2G system as a substitute for a peaking plant will depend on the utility, region, power plant mix, and demand (Kempton et al. 2001). The very need to build peaking plants could potentially be avoided, thereby saving millions of dollars in deferred infrastructure spending.

The second category is the V2G system providing the operating reserve. The operating reserve is the generating capacity that is available to come online within a short time in cases of generator failure or other disruptions to the electricity supply. Operating reserve plants require quick response times, accurate power supply, and are typically used for short durations; these criteria match the capabilities of vehicle ESSs exactly. Utilities must have access to operating reserve plants for all 8,760 operating hours of the year (Letendre and Denholm 2006). There are two types of services, known as ancillary services, which apply to V2G systems and operating reserve – regulation and spinning reserve:

• Regulation service (voltage or frequency response) is provided by generators on automatic generation control that measure the instantaneous difference between load supply and load demand. Regulation can be “up” or “down,” meaning that there is higher demand than supply and vice versa, respectively. These regulation services must typically respond in 4 to 10 seconds.


• Spinning reserves are power plants that are already “spinning,” or ready to provide power to the grid quickly. They must be able to be ramped up to full power in 10 minutes. Although spinning reserves must remain operational at all times, they are rarely used and, when used, they are only in operation for short durations. For example, in 2005, one regional transmission organization (PJM Interconnect, which serves Atlantic coastal states and parts of the Midwest) experienced 105 events requiring spinning reserve deployment. The average duration of the events was only 12 minutes (Letendre 2009).

Services that are potentially available from V2G would have the effect of reducing the electrical utilities’ capital costs of building power plants and reducing the operating costs of these plants. A February 2010 report from Sandia National Laboratories (SAND2010-0815) outlined the benefits and market potential estimates for using aggregate energy storage with the electrical grid generation, transmission, and distribution. The energy storage applications identified in the Sandia report are identified as follows (with appropriate V2G applications indicated in bold italic):

• Electric energy time shift
• Electric supply capacity
• Load following
• Area regulation
• Electric supply reserve capacity
• Voltage support
• Transmission support
• Transmission congestion relief
• Transmission and distribution upgrade deferral
• Substation onsite power
• Time-of-use energy cost management
• Demand charge management
• Electric service reliability
• Electric service power quality
• Renewables energy time shift
• Renewables capacity firming
• Wind generation grid integration.

The above list of potential applications of V2G illustrates the concept attractiveness for electrical utilities (Eyer and Corey 2010).[/font]

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[font size=4]1.3.5 Vehicle Owner Motivation[/font]

[font size=3]In a V2G system, a PEV will be plugged into the grid when not in use and electric utilities, ISOs, or third-party electric vehicle service providers (EVSPs) will have direct access to, and control of, both the charge and discharge of the vehicle batteries for a variety of electric system reliability and economic recharging decisions. In a V2G system, the vehicle owner or fleet manager becomes both a consumer and seller of electrical energy and capacity. Because the vehicle owner controls the source of the V2G capability, the informed owner may be in a position to benefit from the bi-directional flow. Reduced electrical rates in exchange for the V2G power flow or direct compensation may be the motivator to enlist the vehicle owner’s support.

There are three interests for the vehicle owner and they are conflicting:

1. The vehicle is the owner’s mode of transportation and needs to be charged to a sufficient SOC so that it meets the driving needs of the owner when the owner wants to use it. At a minimum, the owner needs to understand the terms and conditions of his/her contract with the electrical utility so that he/she is not surprised with an unexpectedly depleted battery when he/she wants to drive the car. (Note that EVSE designed for this function will likely have customer over-rides or programming available to ensure that a minimum SOC is maintained in the battery to satisfy the owner’s needs.)


2. The vehicle owner will want to earn revenue through energy arbitrage from every kWh of electricity that is discharged from their vehicle’s ESS to the electrical grid or for simply making its capacity to discharge available for such action.


3. Each cycle undergone by the battery will contribute to battery degradation and will reduce the useful life of the battery. The rate of degradation will be of utmost concern to the vehicle owner (and the auto OEM as a warranty obligation), because battery replacement is expected to be expensive in the foreseeable future.

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[kristopher]

8. That actually isn't very helpful because...

...it fails to consider a timeline and specific values for those services.

The primary role of V2G in an emerging EV world and smart grid is going to be reactive power support. I've posted on this a number of times, and I'm not inclined to get into it again; if you have any real interest, go to Kempton's UDEL V2G website. He originated the idea and has been working with Wellinghoff, Chair of FERC, to structure the policies that will support it. He is the authority on the topic, and most of his papers are on his website.

[OKIsItJustMe]

11. The fact that you reject the document I cited, and choose a different source proves my point

V2G does not have a single precise definition. You have one that you like.

Here is the "definition" given in the document I cited.

http://www1.eere.energy.gov/vehiclesandfuels/avta/pdfs/evse/v2g_power_flow_rpt.pdf

[font face=Serif]...

[font size=4]1.2 Vehicle-to-Grid Definition[/font]

[font size=3]V2G technology can be defined as a system in which there is capability of controllable, bi-directional electrical energy flow between a vehicle and the electrical grid. The electrical energy flows from the grid to the vehicle in order to charge the battery. It flows in the other direction when the grid requires the energy, for example, to provide peaking power or “spinning reserves.” It should be noted that this is the way V2G would work if a vehicle had such capability, but there are currently no original equipment manufacturer (OEM) vehicles available to the general public with V2G in the United States.

Studies indicate that vehicles are not in use for active transportation up to 95% of the time (Letendre and Denholm 2006) and the underlying premise for V2G is that during these times, the battery can be utilized to service electricity markets without compromising its primary transportation function. Subsets of V2G technology include vehicle-to-home (V2H; when the electric vehicle is at a residence) or vehicle­ to-building (V2B; when the electric vehicle is at a commercial building). In these cases, the battery power is used to supplement the local building electrical load without transfer to the electrical grid. Note that this still effectively displaces building load from the grid, which effectually provides a load-shed function. Alternatively, if there is a power outage from the grid, this permits emergency backup power to continue building processes.

...[/font][/font]

My guess is what you most dislike about this source is that it mentions degradation of the battery.

[kristopher]

12. I just know what that summary's weakness is, and I shared that with you.

I suspect you are happy with a generalized, entry level summary instead of detailed analysis because you are dedicated to promoting hydrogen fuel cells - which is kind of funny since V2G is also envisioned with HFC. The general nature of the summary allows you to pretend you are saying something meaningful even though you aren't.

Like I wrote, Kempton is unquestionably the world's leading authority on the technology. If you are actually interested on how it provides stackable value to battery ownership (as opposed to playing a gotcha game trying to smear batteries) then you can learn more at his V2G website, where his papers are available.

We're done.

[OKIsItJustMe]

13. A 98 page "generalized, entry level summary" by the Idaho National Laboratory

(Give me a break.)

http://www.udel.edu/V2G/

[font face=Serif][font size=5]What is the Grid-Integrated Vehicle (GIV)?[/font]

[font size=3]The flow of power in and out of an electric-drive vehicle can be valuable to the electric grid, but only if it is provided precisely when needed. The University of Delaware has developed a set of interacting technologies, policies, and market strategies to achieve this value, while meeting driving requirements of vehicle owners. [/font]

[font size=5]What is V2G?[/font]

[font size=3]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. When connections are added to allow this electricity to flow from cars to power lines, we call it "vehicle to grid" power, or V2G. Cars pack a lot of power. One properly designed electric-drive vehicle can put out over 10kW, the average draw of 10 houses. The key to realizing economic value from V2G are grid-integrated vehicle controls to dispatch according to power system needs.[/font][/font]

[hunter]

14. We're all so gullible... and ass-backwards.

If somebody wants me to work for them they should send a car to pick me up.

If somebody wants me to shop in their big box store, they should send a car to pick me up.

Put the transportation burden on big business. Maybe they can put solar panels over their parking lots for charging their vehicles by day, or charge their vehicles off-peak. What do I care?

Let's say I want to shop at Target (I'm not sure why, but let's just say...). I pop open the handy transportation app on my cell phone, tell it I want to visit big box store hell, and a few minutes later a car, minivan, or bus rings my phone when they're at my front door.

Same with work. Like riding the short bus to school.

That way nobody has to bother owning cars. I can rip up my driveway and plant a garden, and I can turn my garage into a neighborhood coffee shop, an apartment for my cousins, whatever.

[joshcryer]

15. It requires more electricity to refine gas for same distance as EVs.

So no.