Notes on Electric Transportation
I just got off the phone with a friend of a friend, who heads up the electric vehicle strategy at one of the largest utilities in the U.S. Here are some of the ideas we covered:
• Especially in the short-term, the opportunity to sell power for EVs has very little upside, as it is dwarfed by sales to industrial customers. However, it has plenty of downside, as even a few Nissan Leafs in a neighborhood charging at Level 2 (about 7 kW) can blow a transformer. Having said that, the company recognizes its obligation to enable its customers to charge their EVs.
• Providing time-of-use rates that would incentivize EV customers to charge at night is not as powerful as one might think. An EV owner has already reduced the cost of his fuel by 75%, simply by making the purchase.
• Energy analysts who look at the average grid mix when determining the validity of EVs vis-à-vis the environment are, as frequent commenter Glenn Doty would suggest, getting it wrong. In general, opportunity charging in the middle of the day is (ironically) the cleanest power, as it’s normally natural gas. Of course, because it’s on-peak, in the absence of low-cost energy storage, such charging will cause more power plants to be built, whose overall footprint will be considerable. But charging off-peak tends to be done with coal, which is, of course, terrible. The real goal is to charge with wind, and plenty of it is being curtailed currently, since it doesn’t match load. Thus there is a path to charge EVs with wind, which would be terrific.
• Re: the EV adoption curve, I pointed out that I was disappointed in the numbers I’m seeing, yet it is true that the curve here is actually steeper than it was for the hybrid 12 years ago.
• Most people who won’t consider EVs are afraid that charging and a limited range will be an unbearable hassle, but most EV drivers learn to adapt to this very quickly.
• Early adopters to date have been families whose household income is well into six figures; adoption by the average family will come when the value proposition becomes more favorable. This means that either the price has to come down or the price of gasoline goes up. Here, I pointed out that the $3.50 a gallon we’re paying for gasoline doesn’t begin to cover the true cost to our national security, to our lungs, and to our environment. I expressed my wish that the political environment would enable us to “internalize the externalities,” forcing those who generate and consume energy to pay the comprehensive costs, rather than passing them along to someone else. If we could do that, it seems we’d find a way to charge our EVs with renewables in a hell of a hurry.
Base load power generation and EV charging are independent subjects. I’ve gotten rather tired with the chicken and egg arguments for why one shouldn’t do something because it isn’t synergistic with the current context. Embedded energy arguments are equally tiring.
I’m a late comer to EV’s in that I’ve only been driving them for about 3 1/2 years. However, that has been more than enough time for me to decide there is little downside besides price, and that is the case with all new technologies. When CD drives came out for our personal computers, the blanks were about $1.50.
Power-wise, it is certainly the case that every grid operator and every substation has their own scenarios they must deal with. It is also the case that infrastructure has been massively under-capitalized for purposes of profit taking, and we are largely in need of a major replacement cycle in any case. Utilities can bite the bullet. I have little sympathy there, and as an investor in utilities, I fully accept seeing the stock or the dividends go down as need be. The profit taking has been artificial and I am not so naive as to think it will continue.
Externalities-wise, I’m right there with you. We’ve been preaching that for many years and the chickens need to come home on that one.
I think the solution to EV charging might occur in two ways. The first thought is a stationary battery at home that is charged during the day while a home PV system is outputing the most it can and the house is generally drawing the least it does while people are at work and school and then this energy is transfered to the vehicle when it arrives home. The downside is that you are effectively adding another loss of efficiency as the first battery charges the car battery and you have a stationary loss of space. The other possibility is being able to change the battery in a car so one battery is home being charged by the PV system during the day and the other is in the car being used and when the vehicle gets home the used battery is changed out for the charged battery. This method has the downside of needing additional room to make the changing of the battery possible and having a battery pack that is changeable and also the same problem as above where you need room to have the battery being charged.
Both of these ideas have the common downside of needing two batteries.
The upside for both of these systems is that power can be sent to charge the battery when the house demand is least. When the fridge and washing machine are running power from the PV system will run these devices and less power will be sent to the battery. When they are both shut off then the power can be shunted to the battery and after the battery is fully charged then the excess power can be shunted to the grid. In this way home PV power is used as much as possible on the spot as it were making it more efficient and with less strain placed on the infrastructure. Even on cloudy days a home PV system generates some power and augmenting that with grid power still would lessen the strain on the grid providing a general benefit. If the battery for the first method I mentioned were significantly larger, perhaps twice the capacity of the car battery, then it would provide for the possibility of being able to take the vehicle out to work during the day, bring it home and charge it while eating dinner for example without loading on the grid, take it out again for the night time activities and charge it again when it comes home making it ready for the next day’s activities. The large home stationary battery might also provide some backup during power outages.
“However, it has plenty of downside, as even a few Nissan Leafs in a neighbourhood charging at Level 2 (about 7 kW) can blow a transformer”
Perhaps the problem has more to do with the Amps rather than the KW’s. in the UK, and Europe, multiple loads of 7KW on a transformer or substation would probably not present too great a problem because we use a higher voltage (230V) and lower current. For 7KW, 230V requires 30.4A but at the US 110V this more than doubles to 63.6A. However the energy losses in the cables are proportional to the square of the current and because of this the IEE wiring reg’s require a cable about three times the area to supply 7KW at 110V than at 230V, 10sq-mm vs 2.5 to 4.0sq-mm.
Maybe therefore part of the answer to providing for an ever increasing demand for electricity in the US would be to gradually adopt a higher domestic supply voltage, such as the EU 230V standard, with modern distribution switchgear and protection, safety should not be an issue any more and the lower currents would significantly reduce the demand for copper.
Level One charging is 120V in the US, but Level Two (to which I was referring) is 240V.