Posting in Energy
When you get an electric vehicle it is cool. But when your neighbors do, then the power grid might not be able to handle the extra load.
Electric vehicles are definitely eye candy, as our very own Andrew Nusca found out when he took the Chevrolet Volt out for a spin. Deciding to purchase an electric vehicle might seem cool, but charging it at home might make your neighbors' light go out.
Today in San Francisco at GreenTech Media's The Networked EV: Smart Grids and Electric Vehicles, PG&E smart grid director Kevin Dasso spoke about the impact electric vehicles might have on neighborhoods bearing the extra load of early EV adoption.
First, Dasso explained how the power grid operates. Basically, you have a power station that sends electricity to neighborhoods by way of transformers that deliver power to a number of homes. Charging an EV to the grid adds about two more houses.
If you overload the grid, you'll end up with a bunch of angry neighbors who don't have power because you wanted to charge your car.
In his talk, Dasso also anticipated what would happen if a few neighbors went out and bought an EV today.
"Look out on the poles, the device looks like a garbage can on top of the pole. That's the distribution transformer," Dasso said.
The power grid in Berkeley was built to handle the homes sucking power from it -- not for plugging in EVs. Dasso described the current power grid of a hypothetical Berkeley neighborhood that has five homes plugged into one transformer.
When the first EV shows up in that neighborhood, it will be the equivalent of having seven homes connected to that one transformer. The utility might have to do an upgrade to the neighborhood to deal with the clustering effect.
It's human behavior to want an EV if your neighbors have one, Dasso said, especially if you were thinking of getting an EV before seeing the battery-powered car roll into the hood. So if two neighbors get an EV, then that's like having nine homes getting feed from one transformer.
The effect is expected to be very localized. Essentially, you're adding an extra subdivision to the grid when a lot of people in one neighborhood use EVs.
Nov 9, 2010
It is absolutely right that neighbors get the things one has and as for as the EV is concerned the electricity it requires make it difficult for them to handle. http://www.national.co.uk/information/winter-tyres.aspx
That comparison is too funny... I have already researched if my Internal "Power Grid" i.e. breaker box could handle the load of an EV... the specs I have found require a 30 Amp Breaker to charge the car... Now since most houses have cable and a main breaker that can handle 200 Amps... that's only a little over 1/6th of a house, and I know that with all my electronics electric water heater, washer/dryer etc running, and stove/ water heater/ dryer all having 20 or 30 amp breakers... when they all fire up as they often do, an extra 30 amps sure does not equal 2 houses! yeah, he's just trying to get more money for this "terrible thing"
As an Engineer, I have a few thoughts on the previous comments. First, a practical electric car has a power need of 20 KW (sub-contact) to 50 KW. Figure that it will be used for an hour for commute. Each way, that gives around 40 to 90 KWH. Recharge load will vary with the battery type and charge time. New Lithium batteries have a recharge efficiency of less than 60%. So, you are looking at 80 to 120 KWH needed every day. A typical house uses about 120 KWH per day. So, you are doubling the electric load. Utilities will typically overload the transformers by about 50% above rating. The supply lines will not be overloaded. The utilities will replace them. Money for that will come from electric rates. With a doubling of demand will come a doubling of revenue. Bonds based on the revenue will pay for it. There may be some increase in rates too. There will be larger wire laied in residential areas. Overhead power is easy. Buried lines are more of a problem. In my area, the Utility has been going through the neighborhoods for several years, placing duct banks underground which include spare space for additional cables. They are looking ahead. A bigger problem is the battery replacement. Plan on the batteries lasting 3 years average. Maybe a little more. Batteries are more than half of the cost of an electric car. That will be the real biggest hurdle for electric cars. It is why they never were a major player. Another problem is with electrical supply. To really go with Electric transportation, we will need to do like France, and build a lot of Nuclear Power Plants. To be well done, we would need a combined cycle system. Moving from Uranium-Plutonium combined cycle to a Thorium-Uranium cycle would make sense, as we have a much larger domestic supply of thorium than we do of Uranium. Fusion would be a great option, but it doesn't work yet. Renewable Energy has other environmental concerns, and doesn't give the amounts we would need.
No one here seems to be considering what the load on the grid would be for those of us who live in the Northern parts of the country where we can have freezing temps all day and occasional sub-zero temps at night. The modern electrically heated house (heat pump or not) uses quite a bit of power keeping things warm. There's not really as much of a drop in power usage at night in those areas unless there's extensive use of gas or oil heat. Cold weather typically is hard on batteries too and they will most likely require a longer charge time in those conditions. Oh, one last thing. What kind of provisions are being made in today's EV for heat during winter driving? Does it affect the range?
EV's are a great concept, but for general use they are far from reality. I find the comparison of adding 2 houses onto the suburbia transformer difficult to believe - I'll look for factual electrical consumption during charging data at another time. As others have mentioned the general plan is for EV charging to occur during off peak hours. For now though EV's are only a good concept, for the industry to be investing huge $'s is shortsighted. $40k that will require a battery replacement at tremendous $'s in 5 or 6 years??? Something for the elite to drive to have an image???
There are several cost barriers to entry for electric vehicles. For one, that claim of 3 hours to 80% charge is only if you have the optional 280 volt charging system installed in your house. I checked with a local contractor, and they want $1,500 to upgrade our fuse panel in the house to accommodate the added current and run the 280 volt circuit into the garage. This 280 volt charger will use up a considerable amount of power...about 2-3 times more than a comparable 16 hour charger. Now, consider that your roads are paid for by the gasoline tax that you are no longer consuming. Already, local and state governments are smarting from the decrease in revenue because people are driving less due to the economy. Imagine when several thousand electric cars enter into this....the governments aren't going to give up their gasoline tax cash-cow so readily! They will figure out a way to tax the electricity used to charge your car...most likely at 3-4 times your KW charge from the power company! This will certainly increase your $1.50 cost to charge your car! And that $1.50? Uh perhaps at the $.08/KWh offered in Texas, but what about places like Hawaii that charges $.20/kwh? Yup, that $1.50 now became $3.00! Add taxes and now we're looking at $9.00 to charge your car! Now, consider that the electric companies will need to increase the cost of electricity usage to the customer for upgrades to handle the added strain to an already antiquated electrical grid. Yup, that $9.00 now becomes $18.00! for under 200 miles per charge! Starting to look like a tank of gas now isn't it! Nope...Until we figure out a way to store electricity and use it more efficiently, this electric car will only be a fad...
Natural gas would be more available at nation wide filling station., the products available through Oil and Natural gas is more plentiful that electricity. John in Ks
As others have pointed out, the electric grid has a lot of unused night capacity when A/Cs, refrigerators, and dryers aren't running, and TVs and lights have been turned off for bed. The whole promise of the smart grid was the grid could communicate with appliances (especially electric cars) to negotiate when the grid could handle the load. If the grid wasn't prepared to take up charging a neighbor's car at 10pm, it could wait until 11pm when more people had gone to bed. The cynic in me says Mr. Dasso is priming the pump politically to get customers to accept a large rate increase for infrastructure upgrades. But when talking about street level transformers, as Mr. Dasso points out, the upgrades are relatively localized, small, and cheap relatively. Whether wide upgrades and large rate increases are needed entirely remains to be seen.
I find it hard to believe that an EV charging up is equivalent to two entire homes. That's two 50" plasma TVs, two computers, two electric dryers, two clothes washers, two dish washers, and two 800W space heaters (or two central AC units), plus other assorted stuff. How is that possible? Maybe Berkley's electrical system was set up in 1900, and the expectation was that everyone would use one or two light bulbs?
GM estimates the Chevrolet Volt will use $1.50 of electricity per day to recharge fully. That does not equal "one home equivalent" of electricity use. We have an electric grid in place with excess capacity overnight - the obvious time to plug your electric car in to recharge. http://www.nypa.gov/facilities/blengil.htm Electric cars which can be charged at home overnight and burn gasoline as a backup for long trips are the obvious immediate term solution to begin our move from fossil fueled vehicles.
We have an electric grid in place with excess capacity overnight - the obvious time to plug your electric car in to recharge. http://www.nypa.gov/facilities/blengil.htm Electric cars which can be charged at home overnight and burn gasoline as a backup for long trips are the obvious immediate term solution to begin our move from fossil fueled vehicles.
Boonsri, I think there is a failure in this idea. Usually people will charge the car at night when the grid is less crowded. Of course this will impact the grid and may have the problem depicted in the video, however there is more time to react because the increase will be noticed in night usage. One thing to notice also is that hidroelectric powered areas are more impacted. Because the water damp will not be filled at night.