GM's promotion focused heavily on "gas saved" and didn't included "electricity consumed" on either their vehicle's display or the OnStar reports. That lack of information allowed the assumption to grow. It's unfortunate, especially now that owners are discovering how much of the range is gobbled up by heater use (and capacity reduction and internal resistance). But it's not like some of us didn't push to have kWh information available. .
Sorry for confusing people. When I asked about PGE for northern california, I was referring to Pacific Gas and Electric. Not Portland... The electricity rates ehre are terrible. They start around 12c per kwh and go up to 40 c per kwh for not that much usage ( around 700kwh per month ).
If you're on E9 it could go as high as $.5/KW during the day if you're on the highest tier. plugin hybrids and EVs in CA don't really save all that much money. The main thing is the energy is domestically produced. I on the CARE plan so I my rates are $.085-$.095 per KW.
But one would usually not recharge during the day. The point of E-9 is to get lower rates in the wee hours of the morning when one would recharge. E-9 gets down to 3 1/2 to 6 cents between midnight and 7 am, as long as you're under 130% of baseline usage. The price you pay is a higher rate during daytime and weekday periods. The only ways to tell if one of these Time of Use rates could help would be to measure your usage by time periods, or to try one out. It varies so much from household to household.
If you have a PIP believe me, you'll want to charge during the day. Or else you'll get the same mileage as a none Plugin in the summer. The 4KW is just too small to last a day's driving. Staying under 130%? you gotta be joking right? Right now, the base line for my area is 305KW. Tier2 is 90KW. That's only 395KW a month usage. It would work if you live in a studio apartment. If you want to meet or beat a volt or leaf's emileage, you gotta charge at least twice a day maybe 3 times a day. E9 is useless if you have a PiP. If you have a plugin larger than 10 KW or a Leaf then E9 would be better because you can charge up that large battery pack during 5 cents/KW period.
Electrical usage varies quite a bit by household - for a family of 2 in a 2-bedroom condo, my last bill was 189 kWh. I'm typically between 6 and 7 kWh per day. Add in a few bonus appliances (chest freezer, dehumidifier, waterbed, electric heat or water heater), some inefficient lighting (I'm using LED and CFL lamps almost everywhere), or a computer that's on 24/7, and that number can jump very quickly.