The fact is, I’ve been pining for an EV for 30 years, since I was in grad school in the “Energy Systems” program at Caltech. When my wife and I bought our first car together (1979 Toyota Corona), I swore it would be “the last gas-powered car I’ll ever get.” Boy, was I wrong about that! So when my daughter took me to the Tesla Gallery in Boulder CO in May (2010) and I test drove the Roadster, I swooned. Two weeks of agonizing soul-searching and finance juggling followed, and I ordered a Roadster. The truly fiscally responsible thought of waiting another two years before I could get a Model S, when I might be able to get a Roadster now – was simply too much to bear.
So 13-1/2 days ago, Roadster (#1014) - *my* Roadster - arrived. Turns out it was one of the first 2.5’s off the assembly line. I’d ordered a 2.0, and they announced the 2.5’s a couple of weeks later. Much to my amazement, in response to my inquiry on supposed improvements in the power management system in the 2.5 (improving performance in “high temperature operating environments”), my Service Rep informed me that my order was being "upgraded"! Maybe it's just me, but Phoenix sounded like a "high temperature operating environment," and I breathed a huge sigh of relief.
The 14 weeks in between – that was really a lot like waiting for a new baby: You’ve got to get everything ready, and you want it all to be perfect. Between when I placed my Roadster order and when it arrived, I wired in the 240V/50A receptacles, had the garage repainted, and had a new epoxy floor put in. (As an aside, I’ve got to admit I was so eager to get ready, I installed the receptacles about two days before the Universal Mobile Adaptor arrived. Remembering incorrectly, I made the mistake of putting in NEMA 10-50’s instead of 14-50’s, so I actually had to do that job twice.) Better than all that, however, just prior to ordering the Roadster, I'd put in motion the installation of a 5 kW photovoltaic system on the house, which also came to fruition during the wait for the Roadster. It went online about two weeks before the Tesla arrived, and immediately started producing about 24 kWh/day of electricity. In fact, my decision to install the PV system was part of my rationalization process in making my Roadster decision: I already owned two Prius’s, had an energy-efficient house, and felt pretty green. How could I possibly spend so much “mad money” on a car like the Tesla, however environmentally cool it seemed, unless I could say that I actually eliminated its carbon footprint (at least, operationally)? I’ve been following various discussions in the last few months about the hidden carbon costs of electric vehicles, and was afraid I’d feel guilty about getting yet another “green” vehicle without first putting some of my other money where my mouth was – namely, start producing a substantial amount of my own energy directly from the sun. Installing a PV system would be far more economically justifiable, so if I did it first, I could then rationalize the Roadster. And why not simply wait another couple of years for a Model S, at maybe half the price? My California-girl wife was quick to point out, “but we can’t drive it to LA either – not enough range; why wait?” So I sold all my BP stock to cover my $9,900 reservation fee (a great investment move, as it turned out – I’m afraid we all know the sad story behind that), and subsequently all my Exxon, Chevron, and Shell stock to make my substantial down-payment on the Roadster. Sure I was earning nice dividends from Big Oil, but not quite enough to make up for the lost capital over the previous two years and the global economic woes. I figured: I can lose money in the stock market easy (almost guaranteed, in fact) – why not instead lose it in depreciation on a (really cool) car? At least I’m not kidding myself! (And who knows, I may have a real collector’s item soon!)
And did I mention - we live in a very energy-efficient "monolithic concrete dome" house. In our area of Arizona, we’re served by a public utility that offers a time-of-use rate plan. If I can shift at least 30% of my energy to off-peak hours, I pay less. Most people do that by compromising a little comfort: higher thermostat setting during the peak hours, putting the water heater on a timer, and intentionally avoiding baking, laundry, and so forth, during on-peak hours. But our dome home has a huge thermal mass which naturally load-shifts its cooling requirements – the single largest power consumption in Phoenix for half the calendar year - to the off-peak hours. It’s almost painless, and is why our on-peak consumption was already less than 15% or better. To be honest, I was actually afraid of going negative on-peak with the PV system (which turns out to pay very poorly), so we somewhat intentionally positioned the panels to produce more off-peak than on-peak energy. (Most central Arizona photovoltaic installations aim for mid-afternoon peak generation, which coincides with peak demand and the most lucrative payback ratio.) Even so, amazingly, we came very close to going negative – this first month of operation is going to show only about 2 kWh/day of billable on-peak consumption. Compare that with our average summer off-peak consumption of about 70 kWh, before the photovoltaic system went in (and the Tesla arrived).
As it turns out, I’ve actually consumed darned near every kWh of solar power generated by my PV system, over the last 13-1/2 days, in my Roadster – on and off peak combined. In other words, much as without the Roadster, the PV system would have lowered my net metered energy consumption, the Roadster ends up being a battery that effectively moves (in more ways than one) all that solar energy I’m generating on-peak, to off-peak. Or looking at it another way, I’m shifting my daily gasoline based energy consumption from a Prius, that I used to drive every day, to the off-peak consumption of the house, courtesy the Roadster. This was a synergy I hadn’t actually thought through ahead of time, but I’m not complaining about how it’s working out.
On the down side, I can already tell I'm going to have to watch my mileage, as I've already put over 800 miles on the Roadster. Before it came, I'd planned on using it for my daily commute. That would account for less than half of those miles. Instead, I've used it for every non-commute-specific trip that didn't need more than two people along. The problem is, it’s too cool to not drive! (Maybe I should confess, since we're talking about the down side for a moment - summer afternoons in Phoenix *might* actually be just a tad too hot to drive - but even when the A/C cuts out to favor the PEM and battery, I just sweat it out. And I figure I'm going to have 9 months to drive with the top off, cooler in every possible way.) I think maybe my mileage (definitely my energy/mile) *will* taper off. I mean, I've only given about 40 "test rides" to friends so far, and wouldn’t you think the novelty might eventually wear off – at least for me?
As for the "My Car/Our Car” aspect, as another blog has put it, I have to say: my wife definitely likes the Roadster, but for the most part, she seems to be just as happy to ride along as drive it herself. Don’t get me wrong - there's no doubt she has fun driving it (if I can keep my mouth shut about how she’s not getting up to the speed limit as quickly as she could)! I guess she's just not a performance junkie. Me, though - I'm a mechanical engineer, and revel in first-hand experience of the physics and engineering of this incredible machine. 30 years later, it’s really a dream come true.