Hi Eric, you have missed one 'Additional Cost'...

Most of the $28,000 will be the cost of the batteries, say $18,000.
These have a life-span of just a few years. So if
they need replacing after 3 years...

Thats an 'Additional Cost' of $6,000 per year.. !!

Pete

At 22:42 20 September 2012, Eric Greenwell wrote:
On 9/20/2012 2:29 PM, Limus wrote:
I was interested until I saw $28K price tag. Jeez, that's more than
what I paid for brand new all electric Nissan Leaf car.

Is your Leaf used for glider launching? If not, probably an irrelevant
observation :^)

Instead, try penciling out the numbers ($ amounts apply to my flying for
a year - 50 flights):

Additional costs:
$280 Interest cost of the $28K
$0 depreciation
$200 added insurance cost
$480 Total extra costs

Avoided costs:
$2000 Tow fees avoided by using auto tow, or low aero-tow
$1000 Retrieve costs avoided (by car, aerotow, etc)
$3000 Total avoided costs

That's a $2520 net savings/year, which is about a 9% return on the
purchase cost, so the financials look pretty good. Now add in how much
you think the intangible benefits are worth (again, numbers for my
flying):

Added value:
$150 Avoiding 3 relights
$500 Avoiding 5 landouts
$200 Being able to fly good flights in unpredictable weather
$200 Flying more aggressively
$200 Starting earlier and/or flying later
$1250 Total added value each year

Now the return is ($2520 + $1250)/$28,000 = 13%

If I owned a LAK 17, I'd be queuing up for the FES, and that's just
using it as a sustainer! If it could really work as a self-launcher, say
in low density altitude places, it would avoid more costs and provide
greater benefits.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz