To look at this further, let us consider the solar energy available in the
Seattle area (again, the worst in the continental USA) over the year. The
results, in terms of sun-hours/day are:
Jan Feb Mar Apr May Jun Jul Aug
Sep Oct Nov Dec
0.92 1.65 2.88 4.04 5.47 6.06 6.23 4.98 3.85
2.09 1.15 0.74
Let us assume that we travel 20,000 miles/year (the US average for a 2-car
family) which consume about 28,000 kWh of energy/year, when we convert the
fuel consumed to kWh. Let us assume we travel less in the Winter, at about
40 miles/day (at total of 6000 miles for those 5 colder months):
· During the 5 colder months the PV on the car delivers only 20
miles/day, so we need an extra 20 miles/day of energy from the utility. Given
that the car gets 20 miles/kWh, then for 5 months we need (5*30*20)/20 =
150 kWh that we need to get from the utility.
· But during the remaining 7 months of the year, we get an average
of 71 miles/day from the PV array on the car, but since we only travel an
average of 67 miles/day, we don’t need any extra energy.
If we add the embedded energy needed to create the solar PV array, where we
assume that a 1.5 kW array produces an average of 1500 * 1.2 kWh/year, and
at the standard 3.7 payback years for solar PV that comes to 6,660 kWh. Over
a 30 year lifetime that comes to 222 kWh/year + 150 kWh/year or 372
kWh/year total, *which is 75 times less* energy than what the average
family now consumes, yet we travel the same speeds for the same distance.
Although the Stella Lux or Stella Vie are not in production they are street
legal (at least in Europe) cars and have been making tours around Europe
for over a year. The team is considering developing a production car,
named “Lightyear”, which uses most of the same technology.
On Sun, Oct 21, 2018 at 3:34 PM Peri Hartman via EV <ev@lists.evdl.org>
wrote:
> The Stella is an awesome example of what can be done. Aside from what
> Lee says, which I think is one area of resistance, another big problem
> is need for a variety of uses.
>
> What I mean is I (or you or the huddling masses...) want something that
> works for a 15 mile solo commute, works to take the family out to
> dinner, works to go skiing (hiking, fishing, hunting, ...) for the day,
> and works to go out of town for the weekend. I think the Stella might be
> able to do the first two, for a large percentage of people. The latter
> two? I doubt it.
>
> Now, for going out of town, it wouldn't be too hard to make arrangements
> to easily pick up a rental. The other case gets harder. You have a lot
> of elevation gain, meaning you'll need a pretty hefty battery since
> solar isn't going to be anywhere near adequate. That means the car gets
> super heavy - like a Tesla - and now the benefits of the Stella are
> impossible. This usage, too, could be handled by a rental. But I doubt
> most people are willing add two hours to an already long day in order to
> use a rental. On top of that, most rental companies don't permit you to
> drive on unpaved roads.
>
> If we, eventually, have autonomous vehicles, perhaps you'll be able to
> own a car for your special purpose activities and fetch one for your
> daily usage. Then, Stella-like vehicles become a real option, I think.
>
> Peri
>
> ------ Original Message ------
> From: "Lee Hart via EV" <ev@lists.evdl.org>
> To: "Electric Vehicle Discussion List" <ev@lists.evdl.org>
> Cc: "Lee Hart" <leeah...@earthlink.net>
> Sent: 21-Oct-18 2:56:18 PM
> Subject: Re: [EVDL] EVLN: The physics of slapping solar panels on cars
>
> >Larry Gales via EV wrote:
> >>When I look at the Stella Lux and Stella Vie, I get very different
> >>results
> >>from the negative views of solar powered cars. I start with the
> >>assumption
> >>that the Dutch students who have won most of the solar car records are
> >>not
> >>actually lying.
> >
> >The problem is that most people assume that EVs must be exactly like
> >ICEs. Typical ICEs today weigh a ton or more, and have the aerodynamics
> >of a brick. All those edgy lines, huge grilles, big fat tires, and
> >rough bottom mean it takes lot of horsepower to drag it down the road.
> >
> >The automakers are building EVs the same way. Big, heavy, poor
> >aerodynamics.
> >
> >But there are other ways to do it. Race cars and airplanes are much
> >lighter, and have aerodynamics based on performance rather than
> >styling. Amory Lovins has been championing the "hypercar" concept for
> >decades. The basic idea is that if you halve the weight, and cut the
> >aerodynamic losses in half, it takes 1/4th as much energy to push it
> >down the road. Yet it can be just as strong and safe, by using modern
> >materials and construction techniques.
> >
> >EVs like Stella Lux and Stella Vie demonstrate how successful this
> >strategy can be. When you have a 4-passenger car that weighs 826 lbs
> >and 1/3 the aerodynamic losses, solar power becomes a viable way to
> >power it!
> >
> >-- Obsolete (Ob-so-LETE). Adjective. 1. Something that is simple,
> >reliable, straightforward, readily available, easy to use, and
> >affordable. 2. Not what the salesman wants you to buy.
> >--
> >Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
> >_______________________________________________
> >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> >http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> >Please discuss EV drag racing at NEDRA
> >(http://groups.yahoo.com/group/NEDRA)
> >
>
> _______________________________________________
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> Please discuss EV drag racing at NEDRA (
> http://groups.yahoo.com/group/NEDRA)
>
>
--
Larry Gales
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