I'm skeptical of his estimated electricity cost; as a Bay Area resident, $0.12/kwh seemed low, so at first I thought he might be in an area of the country with lower energy costs, but he states he's actually in Silicon Valley.<p>I'm not sure how his particular usage and rates compare, but the rates for my most recent PG&E bill are as follows:<p>$0.13627 for the first 487.20 kWh
$0.15491 for the next 146.6 kWh
$0.31949 for the next 340.9 kWh
and then up.<p>In my area, according to my bill, average household usage (for the past month) is 400kWh, and 250kWh for "efficient homes." I'd imagine average use is higher in the summer months due to air conditioning, etc, and higher in the winter months due to heating and lighting.<p>So, right off the bat, $0.12/kWh is low, but perhaps rates were a bit lower when he did this analysis, or he lives in an area with cheaper rates? But let's assume that he's an efficient user of electricity, and uses 250 kWh/month for things aside from the car. He estimated 15k miles per year, at 3 miles/kWh, that's 416 kWh per month, which works out to roughlly $65.50/month, or $785/year, not $600.<p>If we instead assume he's an average user in a home that's not "efficient", it goes way up to roughly $92/month, or about $1100/year.<p>Obviously I don't know this person's exact rates for electricity, or his usage, and it may be the case that there are credits associated with having an electric car that can bring his average rates down or prevent him from going into the higher tiers (as he said, he could often charge for free at work), but regardless an estimate of $0.12/kWh seems strikingly low. I'm sure there are areas of the country where that's reasonable, or even high, but I don't think the Bay Area is one of them.<p>Of all the cost analyses of Tesla ownership that I've seen (admittedly few), I have yet to see one that attempts to take into account the higher marginal electricity cost associated with using significantly more electricity.