Friday, October 21, 2011

Dominion Virginia Power EV Rates Revealed (Part 3)

Calling Dominion

During the Canadian Thanksgiving Day weekend I called Dominion's Electric Vehicle information and sign up line to discuss which pilot project I should choose: Schedule EV or Schedule 1EV, below.  I found out that if I signed up then I'd be getting my new meter before my EV arrived which wouldn't be useful for the program.  We thus decided to punt the decision until after my next meter reading on the 17th of October.  That way, the new meter would be installed during the subsequent meter reading in November, which should be after my LEAF arrives.

Not So Smart Meter

The other thing I found out was that the Smart Meters Dominion installs are an earlier design.  These units are only capable of sampling electrical usage at fixed intervals which allow them to calculate for each of the prescribed Time-Of-Use intervals under the given rate plan.  They don't have the advanced technology of having 3 lines to the house, where, for instance, one has a household line, an EV line and potentially a line to a Solar or Wind generator.

In fact, the Schedule EV program installs 2 meters on your home.  You keep your original meter for your household, ticking off net electrical usage under the standard Residential Schedule 1 rate.  Typically next to this, they add a second meter to the mains which is the smart meter monitoring the EV usage under Schedule EV.  However, if they find it convenient, they may place the meter anywhere where an electrical line in can be tapped, though the location of the current meter seems the most logical.

The other new Smart Meter technology is the ability to create a mesh network, as they're doing in Austin, TX.  This technology allows the customer to monitor their current and historical electrical usage via a wireless network that sends information to Austin Energy.  What's more, these new Smart Meters can communicate with smart household appliances to regulate appliances like a refrigerator or central air conditioning, allowing the power company to reduce household electrical usage during peak hours.  On the surface this may sound like big business controlling we the consumers, but it benefits us too.  After all, throttling our appliances during the most expensive, peak demand will save us money, especially if we're under a Time-Of-Use rate.

Second Meter?

As stated above, folks interested in the Schedule EV plan will be getting a second meter to monitor the EV electrical usage.  Because this is a second meter, it needs to have its own line into the house which must be provided by an accredited electrical contractor.  Dominion's responsibility is only to the meter.  They'll hook up the meter if and only if there's already a line into the house with a empty mounting for a that meter, as would be for Schedule 1EV (household Time-Of-Use).  If your electrician hasn't yet run the line out for the second meter and installed the meter mounting, Dominion can't connect the meter to your EV.

So today I spoke with my favorite Electrical Contractor, Joe from Cullen Electric, Inc..  Unfortunately, for most of the conversation I had him confused with a representative from Dominion, much to my chagrin.  I'm waiting for a call from the Net Metering folks at Dominion to answer a question I still have about hooking up solar panels under one of the EV schedules.  So unfortunately I dragged Joe into a long and only partially productive debate about installing Photovoltaic panels on my home.  My plan is still to consider installing Solar Panels on my home, especially if I can get the guidelines of my HOA overturned this week, but obviously that's not why I asked Joe to call me.  Sorry about that Joe!

Anyway, Joe estimates the job to be about three-quarters of a day's work and estimates about $700 – $800.  Basically, since there's already a circuit breaker panel in the garage for the EV, Joe just needs to pull the 125A 1/0 SER cable out of the main breaker, hook it into a new cut-off switch and then run a wire out from the cutoff to the new meter mounting.  The cutoff switch is for safety since it needs to be within a minimum number of feet from the meter, but is convenient since it doesn't require the current 125A wire to be extended.  As of the time of this writing, I'm still checking with Joe on whether he knows which meter mounting to get but if I do go with Schedule EV, it looks like he can install it pretty close to the Smart Meter installation date, assuming it's 17 November as Dominion indicated to me when I first called.

I'm considering just going for the Schedule 1EV to simplify the work by Dominion and not have to run a new wire out of my house, though I certainly could budget the extra electrical work.  I certainly have always preferred the EV-Only Schedule EV, but it's looking more and more like I'll be going with Schedule 1EV.  But each day this changes and Joe is still trying to track down information on the correct mounting…

Schedule 1EV

Finally, we come to the long sought after description of Schedule 1EV — it's only taken me 8 months to write!  Recall from Part 2 that we start with 4.417¢kWh for fuel, transmission, taxes and other various fixed costs.  We then need to add in the base Distribution and Support rates for Schedule 1EV; these rates are summarized in the following two tables:

Schedule 1EV Rate 16 April – 15 October
Hours Distribution rate in ¢kWh Supply rate in ¢kWh Net Cost (EV) Net Cost (House)
01–05 (Super Off-Peak) 0.000 0.444 $10.32 $0.73
05–10 (Off-Peak) 2.053 1.652 $0.17 $164.49
10–13 (Intermediate) 2.053 3.818 $0.16 $57.92
13–19 (Peak) 2.053 9.501 $0.63 $398.98
19–22 (Intermediate) 2.053 3.818 $0.16 $193.08
22–01 (Off-Peak) 2.053 1.652 $46.59 $56.35
Totals $58.04 $871.56
Schedule 1EV Rate 16 October – 15 April
Hours Distribution rate in ¢kWh Supply rate in ¢kWh Net Cost (EV) Net Cost (House)
01–05 (Super Off-Peak) 0.000 1.388 $32.14 $1.25
05–06 (Off-Peak) 2.053 2.106 $0.04 $11.24
06–11 (Peak) 2.053 4.605 $0.30 $155.89
11–17 (Off-Peak) 2.053 2.106 $0.23 $56.18
17–22 (Peak) 2.053 4.605 $0.30 $179.88
22–01 (Off-Peak) 2.053 2.106 $52.08 $34.65
Totals $85.10 $439.09

This by far is the most complicated rate of all that I've analysed.  Not only is it a Time-Of-Use rate, like Schedule EV, Schedule 1T (The old Time-Of-Use household rate) and Schedule 1S (The Time-Of-Use rate used for houses with Solar Net-Metering), but its seasonal periods break mid-month so it means I have to compute complete months then prorated, partial months in during the summer schedule and add that to prorated, partial months in the winter schedule.  Thus, my sheet does 3 look-ups for each month and each hour, making it bulky, slow, hard to maintain and from which it's hard to get specific details.

What's more, Schedule 1EV is an alternate rate, not an additional rate.  You use Schedule 1EV instead of Schedule 1, not in additional to it like with Schedule EV.  This means that your entire household rate could be effected by the change, not just by the addition of the EV, but now your usage and time of usage matters for everything.  When you run your A/C or Electric Heater, when your Refrigerator cycles or when you watch Television or Browse the Internet can all effect your total electricity rate.

Since my home is currently on the 2-tiered, fixed-rate Schedule 1 plan, I don't have any information about how many kWh of electricity I use at say 10 am (hour 10) or 10 pm (hour 22), or when I may be my peak usage and when do I use the least.  The EV is easy to estimate because I know when I plan to charge it, how long it takes to charge and thus when the charging will typically stop, not so with the whole household.  All I know for sure is the total electricity usage in my one month billing cycle.  Any more detail than that, and I have to guess.

Estimating Home Electricity Usage

I've literally wanted to post this since I wrote the first part of this article back in February.  Indeed, it's the entire inspiration for this series I've made about explaining the electric rate.  Of all the things I've discussed thus far, I can show evidence, trace steps, and point to solid sources of information to back up my claims.  When it comes to estimating household electrical usage, however, things reduce to an educated guess.

Daily Electrical Usage Curve

To start with, I decided to assign an arbitrary point system to my daily electrical usage.  The points don't correspond to any real-life value, they just follow the rule that if hour x value is greater than that for hour y, then that hour is estimated to use more electricity and if the value at x is twice y then x used twice as much electricity as y,  The following table details the numbers I used and some of my reasoning.

Daily Electrical Usage (Estimated)
Hour Value Percent Reasoning
00 0.25 0.30% Sleeping, for the most part
01 0.25 0.30%
02 0.25 0.30%
03 0.25 0.30%
04 0.25 0.30%
05 3 3.56% Wakie, wakie!
06 6 7.12% Get ready for work (or sleep in on weekends)
07 6 7.12%
08 6 7.12%
09 6 7.12%
10 2 2.37% At work with alarm active or relaxing in front of the Television or Computer
11 2 2.37%
12 2 2.37%
13 2 2.37%
14 2 2.37%
15 2 2.37%
16 5 5.93% Chillin after work
17 5 5.93%
18 5 5.93%
19 7 8.31% Primetime: The height of activity
20 7 8.31%
21 6 7.12% Evening slowdown
22 6 7.12%
23 3 3.56% Getting ready for bed

Phew!  So, that's what I estimated.  I took those numbers, summed them to get a total points used, then divided each by that number to get a percent usage, which you can see next to the raw values above.  I take these percents and multiply the total monthly usage by them to get the estimated total monthly electrical usage for that hour of the day.

Because I've never been on a Time-Of-Use rate before and I'm no-where near confident with these numbers, I would be happy to hear from one of my readers to show my my mistakes.  Barring that, I could just go with the Schedule 1EV rate and see what happens.  They won't break out my usage in hours for me, as I explained above, but I could at least see if my estimates were near the mark.

Rate to Rate: Who's cheaper for a household?

Up until now, I've only been talking about EV rates.  The amount of money it costs to run the household electricity is different than that for an EV because the costs for an EV already assume some electricity usage so the electricity is never metered from zero.  For instance, under Schedule 1, there are 2 tiers of electrical usage for the base Distribution and Supply rates: the first 800 kWh are charged charged at one rate and anything above that at another.  As such, since my home already uses more than 800 kWh per month, my EV would always be charged the abouve 800 kWh rate.

In addition to this, there are taxes like the State Consumption Tax, the Special Regulatory Tax and the Local Consumption Tax, as well as the Fairfax County tax.  In the case of the three Commonwealth taxes, they are each 3-tired taxes.  In Part 2 I estimated that most of my EV's electricity would be in the in the first Tier, with a little less than ⅓ in Tier 2.  With the household, we're counting from zero so all again most usage is at Tier 1 with a bit in Tier 2 with the above 2,500 kWh usages over Summer.  Also, where as the Fairfax County Tax has already reached its $4 cap by the time we start to count the EV, that entire $4 is paid at the household level.

Household Rate Fixed Costs

Fortunately, the only thing different between the Schedule 1 rate household and the Schedule 1EV rate household is the Distribution and Supply usage rates.  Even the monthly rate of $7 is the same under both schedules.  These invariant values a summarized in the next table:

Name cost in ¢kWh Annual Cost
Schedule 1 & 1EV: Distribution (Monthly cost, $7.00) $84.00
Rider C1: Peak Shaving 0.009 $1.93
Rider C2: Energy Efficiency 0.044 $9.43
Rider S: Virginia City Hybrid Energy Center 0.280 $60.03
Rider R: Bear Garden Generating Station 0.117 $25.09
Rider BRC: Base Rate Credit -0.132 -$28.30
Rider T: Transmission 0.616 $132.08
Fuel Charge Rider A 3.289 $705.19
Sales and Use Surcharge 0.056 $12.01
Consumption Taxes (Tier 1) (< 2.5 MWh) 0.155 $31.08
Consumption Taxes (Tier 2) (2.5 MWh ≤ x < 50 MWh) 0.099 $1.38
Consumption Taxes (Tier 3) (≥ 50 MWh) 0.075 $0.00
Fairfax County Tax (Min 56¢; Max $4) 0.605 $48.00
Totals 4.430 $1,081.92

As before, we need to explain the base rate calculation here.  I currently estimate about 21,441 kWh per year of electrical usage in my household given the pattern of data I have going back almost two years.  How this breaks down in terms of the Consumption Taxes is 20,051½ kWh of that is under the Tier 1 level and only 1,389½ kWh falls under Tier 2.  I again use these estimates to calculate the last 0.151¢ of the tax total.

I've also eliminated the County Tax from the calculation but not because it isn't paid, but because it's always always $4.00 per month for me, regardless of how much electricity I use.  For this rate to be relevant, I'd have to use less than 661.157 025 kWh of electricity in a given month and that is no-where near happening.  After all, I'm never even going below 800 kWh to stay within the Schedule 1 Tier 1 Base rate.  Thus, the County Tax and Monthly Distribution rate are not counted in the total cost per kWh, but are included in the annual totals.

I spend about $1,081.92 each year … on all secondary items

In summary, I spend about $1,081.92 each year in electricity regardless of rate schedule on all the secondary items, riders and taxes.  This value is without the Base Rate, which turns out to be the lion's share of the calculation.

Comparison of Rate Schedules

As I stated before, Schedule 1 is a 2-Tiered system.  It's also a seasonal schedule, with different rates depending on the time of year.  These rates are summarized in the following table.

Rate Category Non-Summer Rate, 1 October – 31 May, in ¢kWh Summer Rate, 1 June – 30 September, in ¢kWh Net Cost (EV) Net Cost (House)
Distribution ≤ 800 kWh 2.233 2.233 $0.00 $214.37
Distribution > 800 kWh 1.260 1.260 $90.49 $149.20
Supply ≤ 800 kWh 3.795 3.795 $0.00 $364.32
Supply > 800 kWh 2.927 5.773 $278.48 $574.71
Totals $368.97 $1,302.59

Putting it all together

Compare this to the results from the Schedule 1EV rate above.  In the tables describing the Schedule 1EV rate, we have the totals for both the car and the household for the base Distribution and Supply rates.  The household rates are based on the estimated electricity usage from that section, and as such are only my best estimate for how much it would cost under Schedule 1EV: my own mileage may vary.  Summing together the values from that table and the one for Schedule 1 and finally pulling in the results for the Schedule EV in Part 2, we can finally compare each of the above rates:

Rate Schedule 1 Schedule 1 with Schedule EV Schedule 1EV
Distribution Cost per Year (EV) $90.49 $98.83 $52.17
Supply Cost per Year (EV) $278.48 $70.63 $90.97
Subtotal Cost (EV) $368.97 $169.47 $143.14
Total Cost (EV) $686.16 $486.66 $460.33
Distribution Cost per Year (House)1 $363.56 $363.56 $434.96
Supply Cost per Year (House) $939.03 $939.03 $875.69
Subtotal Cost (House) $1,302.59 $1,302.59 $1,310.65
Total Cost (House) $2,384.51 $2,384.51 $2,392.56

The Subtotal in the table above contains the sum of the Distribution and Supply costs and the Total adds this to the cost for everything else, including Taxes, Fuel, Transportation and the various other Riders.

The main take-away here is that if my estimates are correct, there's not much difference for the household electricity cost under Schedule 1 and Schedule 1EV; my calculations show less than $10 per year!  Stranger though is that the Distribution is about $70 higher under Schedule 1EV but about $60 lower than Schedule 1 for Supply.  Secondly, as you can see, the cost to run an EV under Schedule EV and Schedule 1EV doesn't differ much either.  Schedule 1EV looks to be about $25 cheaper than Schedule EV, but both are clearly less than half the rate under just Schedule 1.

What if the LEAF had a 6.6 kW charger?

I would be remiss if I didn't do the same analysis for the Schedule 1EV that I did for Schedule EV with respect to 6.6 kW charging.  Specifically, the $98.68 I pay per year for charging my LEAF from hour 22 to hour 1 (Off-Peak) could be reduced to a mere $0.22 cents and my Super-Off-Peak per year goes from $42.46 to $65.38 per year because of the greater overall electricity usage.  Thus, the cost to run the LEAF under Schedule 1EV goes down to $384.78 per year, about $75 in savings per year.

And that's all you need to know when you choose a new EV rate schedule.  So call Dominion right now: 1-866-566-6436 and join the EV Rate Revolution!


1Doesn't include the Monthly Charge since this is already assumed in the fixed cost independent of the rate program.