Tuesday, February 1, 2011

TOU for EVs coming to Virginia!

Dominion Virginia Power Proposes Rate Options for Charging of Electric Vehicles

As reported earlier, Dominion Virginia Power is planning to rebid a new rate schedule for Electric Vehicles in the Commonwealth of Virginia later this year.  The proposal would go before the State Corporation Commission probably this spring and if accepted would mean that 1,500 lucky participants would be allowed to participate in the new rate on a 1-year, trial basis.

Dominion is considering 2 new rates for its residential customers.  One rate would be purely for Electric Vehicles and would have high on-peak and low off-peak usage charges.  The other would be a household rate similar to the Schedule 1T currently allowed to some Dominion customers, though at slightly higher rates.  As I'm currently happy with my household rate under Schedule 1, I'd still prefer the option for a separate TOU Meter, as stated previously.

Now, the question is, what will this new rate be?  According to the press release, Dominion expects a cost of 35¢ for a 40-mile commute under the Electric Vehicle only rate proposal.  This distance is significant because it is also the quoted electric range of the Chevrolet Volt.  Therefore, if we take battery capacity of the Chevy Volt and divide 35¢ by it, we should get the cost per kWh of the new off-peak rate.  The problem is, which value for the Chevy Volt did Dominion use in this computation?

Total battery capacity of the Chevy Volt is 16 kWh, but the Volt only has a usable range of 10.6 kWh.  What's more, Wikipedia quotes the EPA's calculated efficiency of 36 kWh100 mi, or 2.78 mikWh.  Given each of these, the rate (for Generation and Transmission, combined) could be any one of 2.188¢kWh over the entire 16 kWh battery pack, 3.365¢kWh over the 10.6 kWh usable range of the pack or 2.431¢kWh based on the EPA electrical rate of 36 kWh100 mi for 40 miles totaling 14.4 kWh.

On the other hand, if the 40 mile range is based on the Nissan LEAF, then we know that the LEAF can go about 100 miles on its 24 kWh battery.  Thus, 40 miles represents 40% of 24 kWh or 9.6 kWh.  Divide the 35¢ quote from Dominion by this and you get 3.646¢kWh.  As such, I'm inclined to believe the rate is closer to kWh.  Either way, since my daily commute will be closer to 75 miles per day, I'd expect to be paying about 66¢ per day in Electricity under the new rate schedule, or about $4.59 per week.  Compare that to about $45 spent in gasoline each week and you can see why I want to go electric on this new rate schedule.

>Consider also that the kWh is still half of the current summertime rate under Schedule 1, 7.033¢kWh during the 4 summer months; 4.187¢kWh the other 8 months.  What's not clear is if there'll be a separate $12 per month meter charge, in which case the rate becomes less appealing.

If we assume the new TOU rate for EVs will be kWh for off-peak and the same as Schedule 1T, 13.977¢kWh for on-peak, with a $12 per month charge for the second meter, my estimated annual cost for the EV's electricity will be about $327.42 per year.  Although this sounds good, I estimate my cost under the current Schedule 1 to be $311.07, which is actually cheaper!  This is mainly due to the monthly meter fee and the fact that the Clipper Creek CS-100 EVSE draws about 5 watts of power when idle, including during peak electricity hours.  If I could eliminate the monthly meter cost, my cost goes down to $183.42 annually; if I could shut off my EVSE during peak, that'd save a mere $3.09 if the Schedule 1T peak rate is used.

It also remains to be seen if a full 20+ kWh can be drawn for the entire 7 - 8 hours required to charge the Nissan LEAF under the new TOU EV rate. If the off-peak rate isn't a full 8 hours per night, it may be impossible to charge the LEAF without going on the peak usage rate.  In fact, if I hope to leave my house at 05:30 each morning, the off-peak better start absolutely no later than 22:00 — or the 2012 LEAF could just add a 6.6kW charger!

Of the 1500 participants in the pilot program, 750 will be chosen to go under the EV-only TOU rate and 750 to go to the household TOU rate for EV owners.  As the press release states, the program will begin 90 days after the State Corporation Commission approves the new rate and will end 30 November 2014.  Of course, if the new rate is approved in September, and I'm able to get my LEAF in December, I should be well-placed to join the pilot program.  If the approval comes earlier or my LEAF arrives later, I won't be able to get in the program from the beginning but might still be able to join as late as 1 December 2013, assuming there are still some opened slots in the program.  I would then be able to use this new rate for a year while Dominion closely monitored my electricity usage.

All in all, exciting news, even if it can't beat the current Schedule 1 rates, though this too may change as we learn more about the proposal. Stay tuned…