JoeS wrote:Demand charges are hideous - for example, PG&E's demand rate is $18.64 per kWh (that's right, NOT 18¢/kWh!), and as I understand it this then lasts through the entire billing cycle.
tsk, tsk, Joe- probly a typo, but I'll take you to task for perpetuating some of the misunderstandings around demand charges. Demand is instantaneous power measured in kW, similar to throttle position, while consumption is energy consumed over time, in kWh (akin to distance travelled). ..In my day job as a school district energy manager, instantaneous demand ranges between 100 kW and 1200 kW for a high school, and high demand is only experienced during less than 3% of our operating time, but makes up at least 40% of the electric cost! ..
jray3, you're right, in reading the PG&E table I missed the 'demand' column being $/kW and not $/kWh! My bad, with apologies, and I'd love to have a separate discussion with you about this whole subject the next time we visit.
Back on topic, jray3's example shows the disproportionate penalty being paid for such 'demand' charges. Since multiple DCQC stations at one location may well trigger such demand charges, the legislative approach could be to exempt EV DCQC stations from such a tariff (if that's the proper word), or the pragmatic approach would be to install batteries to ensure the demand peak power point is never exceeded. It would not be acceptable to throttle back all the cars charging to keep this limit from being exceeded. Along this line, two Tesla superchargers normally share a common input (the stations are labeled "1A" & "1B", "2A" & "2B, etc.) so when a Tesla plugs into a station number that is already being used by another car, then the power to both is reduced - as I understand it, with priority given to the car that's already charging. During my cross-country trip I paid a lot of attention to this and was usually successful in avoiding power sharing.Edit:
ChrisEV, would you have taken that 160km winter trip in the i-MiEV if you had free
CHAdeMO L3 spaced every 65km along the way?
I suspect that free (subsidized) L3 charging will gradually disappear. Given some of the present L3 cost structure (e.g., EVgo), at today's gasoline rates this makes long-distance BEV travel not only somewhat painful (timewise with <50kW stations) but also uncompetitive financially with ICE (except for Tesla).