Power estimating cost?

[weylan]

Ok, I live in CA where I have PGE. And the tiered energy rate.
I am on e9a.

So my bill for electricity is now about $211 a month.
Using 1000kw a month.
We have the new smart meter.
So how are people estimating the powere cost to put into charging calculations with the tiered rates?
It has to be some blended average and calculation?

I guess I can average the kw used over the month as an average but wish it was a bit more accurate.

 

[planet4ever]

If you are trying to determine how much the LEAF is costing you, then with tiered rates you need to think of it as a marginal cost. If you were in the same house for two years or longer before getting your EV, look at your old bills (or get them from PG&E) and see how much electricity you were using in the same month of the previous years. (You want kWh, not $, because the rates keep changing, and you can't compare E1 with E9 anyway.) Assume the difference from kWh each month this year is what your LEAF is using.

If E9 wasn't a TOU schedule then it would now be easy. PG&E tells you how many kWh you used in each tier. You would treat the energy used by the LEAF as the last kWh used during the month -- that's where the marginal part comes in -- and multiply tier amounts by tier rates to get the cost. Simple example: Last month you used 340kWh at tier 1 and 250kWh at tier 2. You figure your leaf used 300kWh, so you would calculate its cost as 250kWh at tier 2 and the other 50kWh at tier 1.

But since E9 is a TOU schedule you first have break everything into fractions based on your relative % use of Peak, Part peak, and Off peak. For example, if your total use for the month is 30% peak, 50% part peak, and 20% off peak, multiply your LEAF usage by 0.3, 0.5, and 0.2 to get the peak, part, and off usage of the LEAF. Do the same thing for your usage in each tier. Now do the marginal business three times (for peak/part/off), and add all the period and tier costs to get the LEAF cost.

A spreadsheet is highly recommended!

Ray

 

[cwerdna]

Ok, I live in CA where I have PGE. And the tiered energy rate.
I am on e9a.

So my bill for electricity is now about $211 a month.
Using 1000kw a month.
We have the new smart meter.

Not that this directly answers your question, but 1000 kwh a month is quite a bit, at least to me.

My last PG&E bill (covers 7/14 to 8/13) was $47.27 in total. Electricity includes taxes was $36.46 of it. I used 269 kwh and I'm on E1. I too have a smart meter. PG&E claims I'd save $50/year if I switched to E6 Smart. I might do so once we cross out of what they consider "summer".

I have no central AC but I'm home all the time (mostly on my computer and/or watching TV) as I'm not working at the moment. I do live in a fairly large house (~2500 sq ft.) but by myself (long story) and have no PHEV or EV yet... If I were working, my electric bill should be significantly lower.

If costs are a concern, you might look into ways of conserving to get that bill and usage down, esp. out of the higher tiers. You could start by buying a http://www.p3international.com/products/special/p4400/p4400-ce.html" onclick="window.open(this.href);return false; or a fancier model and changing some usage habits.

edit: Whoops, originally thought you didn't have a PHEV/EV yet. What was your usage like for the same month last year, before you had the Leaf?