The new Electric Cessna 172

In article ,
Vaughn wrote:

On 12/30/2012 1:16 PM, wrote:
If you look at the wing area of a 172 and calculate how much power you
can get, you find they aren't much good for charging the battery either
unless you go days between flights.

Agree. However, if someone wants to own a $200,000 plane and just wants
to fly it for an hour or so once a week it might work. Are there any
folks like that? Yes! But few of them would admit that to themselves
before buying a plane. It's a behavior they drift into later.

I can tell you that most of the non-FBO planes at my local airport
seldom fly. Even some of the FBO leasbacks sit unused for days at a time.


Also, solar panels aren't terribly vulnerable to hail. Otherwise, there
would be little point in mounting them on rooftops.
Rooftop solar panels are mounted at the latitude of the location to
receive maximum power, so a hailstone will hit at an angle of about 30
to 45 degrees from most of the US and tend to glance off.

The solar panels on a wing are going to be horizontal and will take a
direct hit from a hailstone.

There are many places in the US where it is not unusual for hailstones
to dent the tops of cars.

I have watched my share of hail, and seldom does it fall at a 90 degree
angle, so I doubt your theory. My home's panels are mounted at a less
than optimum angle because I am quite worried about hurricane winds and
not worried at all about hail, even though hail happens here.

Today's solar panels aren't glass and aren't terribly fragile. A
rooftop isn't a terribly friendly environment, yet panels last for
decades. I would judge that most PV panels are less prone to hail damage
than a typical aluminum wing skin, certainly no more.

Still, we agree that solar panels on a wing make little sense. They
would be costly, they would add little to the usefulness of the plane,
and they would add weight and complexity.

Also, nobody has remarked on those little wind turbines. Yes, I know
that they are an attempt to recover energy from the wingtip vortex, but
those things will add weight and drag. It would make far more sense to
reduce the vortex with winglets or a better wing design.

Further, adding blades to a prop is unlikely to improve its efficiency.

When you add the questionable solar panels, the questionable prop, and
the questionable wind turbines, I find myself thinking "vaporware".

Vaughn

.... and balonium technology!