Wind/Solar Electrics ???

On Wed, 14 Dec 2005 15:02:56 -0800, "RST Engineering"
wrote:

After much thought and ponderance, I've come to the conclusion that to
electrify the hangar using Pacific Gas & Electricity (PG&E -- Pigs, Goats,
and Elephants) isn't clever. By the time you get them to hang a meter
($5k), trench from the power pole to the end of the row of hangars, conduit
romex to 35 hangars at a cost somewhere around $50k ($1500 per hangar), and
then pay the monthly electric bill, you could buy a hell of a wind/solar
system and perch it on the (flat) hangar roof.

Before I flail about gathering data, has anybody on these ngs actually
installed a design whereby a hefty solar panel charges a hefty battery to
run a hefty inverter? It doesn't have to be absolutely "clean" sinewave
power as all we are running are fluorescent shop lights (about 400 watts
worth), every now and again a small compressor, a small drill press, a small
grinder, but none of these last few at the same time.

My hit on it is that a 2 kW inverter would be more than enough to handle the
AC side of it, and a bank of 12 volt truck batteries would work for the DC
side of it, but there are the problems of parallelling large batteries, how
to combine the outputs of solar cells and wind generators, and a reasonable
source for all this stuff.

There are issues around protecting the solar cells from hail, which we do
get from time to time, battery acidic gases inside a hangar where a very
expensive lump of aluminum is sitting for months on end, sizing the solar
cell and wind generators, and other considerations along these lines.

Comments appreciated.


Jim


Jim,

As one who lives "off-the-grid" in eastern Maine, (and for similar reasons,
I might add -- excess costs to run power here), perhaps I can be of some
assistance. We use both wind and solar to power our home, and also have a
backup generator. The problems of coordinating all these things has been
solved with readily available technology. As has all of the other issues
you mentioned.

In order to make an intelligent decision and design an economical system,
your very first step has to be to estimate your electricity usage as
accurately as possible. In addition to adding up your daily consumption in
kWh or amp-hours, you also have to consider peak loads. And, especially
since you may be using a compressor, you will also have to consider the
startup surge -- with a compressor this may be five to ten times the
running amps. That information should be decipherable from the motor face
plate.

The next step is to assess your solar resource, and there is information on
the web available for that. Being at an airport, my advice is to forget
about wind. You need to have a wind turbine on a tower high enough to get
out of turbulent air, in order to make it worthwhile. The required height
would encroach upon the FAA mandated clear zones.

I'd be happy to help if you like.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

It seems as though we are trying to build a cathedral foundation to hold an
outhouse. It isn't like I'm LIVING in the hangar, nor am I there working
all day every day. Sure, lights when you are elbow deep inside an engine
are nice, but hardly bleeding edge solar design. What? Ten fluorescent
fixtures with 80 watts of bulbs each? A drop cord with another 20 watt
fluorescent bulb? Perhaps a hand drill twice a day WHEN you are working in
the hangar?

As to the compressor, drill press, grinder etc., a gas generator for the few
times a month you need them is quite in order and certainly less expensive
in both the short and long term than gearing up for 100% solar for the
peaks. And, if you design the system correctly, letting the gas generator
run for an hour every time you fire up and letting the batteries take a full
charge from an inexpensive battery charger can add to the output of the
solar system.

I've done a little digging and it seems that Great Plains has the best
pricing on solar panels. Harbor Freight has a little better pricing, but I
need something that I can reliably get month in and month out (I'm the
guinea pig for about 50 hangars) and I can never rely on Harbor Freight to
have what I need when I need it.

My best guess after doing a little educated digging is that I can come up
with a system I can live with for a little over 1 AMU.

(For those of you not on the aviation newsgroups, an AMU is a measure of
money used to disguise the true cost of airplane ownership from other ...
ummm ... family members who might think that clothes, food, and other
nonessentials take priority over flying. 1 AMU = $1000US.)


Jim

In order to make an intelligent decision and design an economical system,
your very first step has to be to estimate your electricity usage as
accurately as possible. In addition to adding up your daily consumption
in
kWh or amp-hours, you also have to consider peak loads. And, especially
since you may be using a compressor, you will also have to consider the
startup surge -- with a compressor this may be five to ten times the
running amps. That information should be decipherable from the motor face
plate.

On Tue, 20 Dec 2005 10:29:12 -0800, RST Engineering (jw) wrote:

My best guess after doing a little educated digging is that I can come
up with a system I can live with for a little over 1 AMU.

(For those of you not on the aviation newsgroups, an AMU is a measure of
money used to disguise the true cost of airplane ownership from other
... ummm ... family members who might think that clothes, food, and
other nonessentials take priority over flying. 1 AMU = $1000US.)


"Aircraft Monetary Unit?"

I've heard that a boat is a hole in the water lined with wood, into
which one pours money. ;-)

Do airplane people have a similar saying? I have only a little bit of
experience with airplanes - I logged 4 hours in a Cessna 150 before the
local flight school got shut down because of fuel considerations, and
I've sat in a DC-9 simulator, and had a simulated airplane ride where
I drove, but I've never gotten into any of the cameraderie, like one
would do as a skydiver.

Yeah, that's it - the best experiences I've ever had with airplanes
has been either abusing them or jumping out of them. ;-P

But, do airplane guys use the term "money hole" like boat and house
owners?

You can't "pour" anything _up_, you know, albeit I have heard that
humans were created by water to transport itself uphill. ;-)

Cheers!
Rich

Rich Grise wrote:

You can't "pour" anything _up_, you know, albeit I have heard that
humans were created by water to transport itself uphill. ;-)

How about suck, as in "an airplane is a rather small hole in the sky made
of aluminum or cloth and wood that sucks the money right out of the owner?"

--
Peter

Rich Grise wrote:

But, do airplane guys use the term "money hole" like boat and house
owners?



We drill expensive holes in the sky

Boring $100 holes in the sky ... going fifty miles for a $100 hamburger ...
standing in front of a fan tearing up $100 bills ... dozens more.

Jim


"Rich Grise" wrote in message
news
I've heard that a boat is a hole in the water lined with wood, into
which one pours money. ;-)

Do airplane people have a similar saying?

I've heard that a boat is a hole in the water lined with wood, into
which one pours money. ;-)

Do airplane people have a similar saying?

An Airplane is a large mobile fan into which the owner is obliged to
throw handfuls of money (to watch it blow away).

David Johnson

On Tue, 20 Dec 2005 10:29:12 -0800, "RST Engineering \(jw\)"
wrote:

It seems as though we are trying to build a cathedral foundation to hold an
outhouse. It isn't like I'm LIVING in the hangar, nor am I there working
all day every day. Sure, lights when you are elbow deep inside an engine
are nice, but hardly bleeding edge solar design. What? Ten fluorescent
fixtures with 80 watts of bulbs each? A drop cord with another 20 watt
fluorescent bulb? Perhaps a hand drill twice a day WHEN you are working in
the hangar?

It's not a matter of building a cathedral foundation, but rather trying to
design the least expensive foundation.

But I guess if you're going to light 35 hangars with ten fluorescent
fixtures that are on for a few minutes each day, you won't need much.


As to the compressor, drill press, grinder etc., a gas generator for the few
times a month you need them is quite in order and certainly less expensive
in both the short and long term than gearing up for 100% solar for the
peaks.

Very reasonable, and what I would suggest depending on how much the surge
is. Of course, that means you'll have to have wiring so that those items
will plug directly into the generator, rather than going through the
inverter.


And, if you design the system correctly, letting the gas generator
run for an hour every time you fire up and letting the batteries take a full
charge from an inexpensive battery charger can add to the output of the
solar system.

It is extremely inefficient to bring the batteries up to full charge using
the gas generator. Batteries charge more slowly as they approach full
charge. Better get a reliable generator, then.



I've done a little digging and it seems that Great Plains has the best
pricing on solar panels. Harbor Freight has a little better pricing, but I
need something that I can reliably get month in and month out (I'm the
guinea pig for about 50 hangars) and I can never rely on Harbor Freight to
have what I need when I need it.

My best guess after doing a little educated digging is that I can come up
with a system I can live with for a little over 1 AMU.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)