[Ladogaboy]

This again? For his application, that is absolutely incorrect. He was clearly trying to take into consideration the cost of charging his Volts vs the cost of running non-EVs, and for that it all gets billed at the latter tiers (probably some 3 and some 4 in his scenario). Assuming his previous load always put him in Tier4 as he said, the answer to his "how much did my bill go up" its going to be VoltKWHUsed * Tier4CostPerKWH. Simple as that. VoltKWHUsed * AvgKWHCost is totally the incorrect answer for what he was solving for.

And this again? By your logic, if he now goes out and buys a replacement refrigerator that uses 100 kWh/month, that refrigerator is now costing him the highest possible rate because it was the last thing added to the power bill. Now, because the old refrigerator is out, and the new one is in, the Volts move down to a Tier 2 rate instead of a Tier 3 rate? Arbitrarily determining which Tier an electronic device falls under based solely on the point in time in which it was added to the system is illogical.

If he wants to know how much his power bill will go up after buying a Volt, that answer is simple. Old bill subtracted from new bill. The rates of the various Tiers do not and should not be considered.

If he wants to know how much it is costing him to charge the Volt, he can either track specific rates, times, and usages of the Volt, or he can simply take the average rate he is paying for electricity and multiply that by the number of kWh the Volt uses.

In my opinion, the simplest solution, though possibly hard for many non-EV owners to fathom, would be to total all energy expenditures. Pre Volts, his power bill was X + $700 (gasoline). Post Volts, his power bill is (X + $200) - $700.

The trick is figuring out what you are solving for, and he, specifically, wants to know how much it costs to charge the Volt. So in his case, Don is right: He should be using his average rate. Sure, that makes all of his other electronics more expensive to operate, but you can't, arbitrarily, assign all of those increased expenses to one electronic device.

 

[Ladogaboy]

Micro analyzing the Volts charging and allocating those costs to other appliances to when they were run is a mental exercise that doesn't change the increased cost of my electric bill.

Which is technically a decreased electric bill because your overall energy costs are hundreds of dollars lower. So, essentially, sans mental exercise, your Volt is making everything you own that requires energy cheaper to run.

So again, all you are really calculating is how much your power bill went up, which is a moot point in the greater scheme of things.

 

[Ladogaboy]

When people ask me how much it cost me to charge my Volt, they are asking the question because they are thinking about purchasing one. If I were to tell them, it depends....and then give them all of the technical jargon, the question to the potential consumer goes unanswered.

But that is EXACTLY the right answer. When I am in Northern California, it costs me about $15 a month to charge my Volt. Many other Volt owners share a similar experience. Some pay less than that because they can charge free at work or at certain businesses. Some people were already in Tier 3 or Tier 4 rates when they got the Volt, so according to your math, they could be paying $100 a month (how much their power bill increased). There is a huge variance, but if your purpose is to inform a prospective buyer, you should always provide the caveat that your experiences aren't universal (i.e., it depends).

It works the same way with mpg. I had someone approach me and ask, "Does that car really get 80 mpg?" My answer: "Yeah, the average seems to be about 80 mpg. Some get a lot more. I only get about 50 mpg."