Wind/Solar Electrics ???

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

Reply to
RST Engineering
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"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

That's true, but they are about half the price that they were about ten years ago. That said, a small Honda generator when you really need a couple of kW and a few watts of solar panel to keep the aircraft battery batting and the keepalives on the radios keeping may be the hybrid way to go.

Well, we are at 3000' on the west slope of the Sierra on the top of a small hill with nothing (literally) between us and Japan except for a wire fence, and it's down {;-) We get some decent winds, but nothing you can count on. Today, for example, the peak wind was somewhere around 7 knots and the average somewhere around 3 or 4 knots. Then again, last week we had a howler come through here at 40 knots and last for a day. Nothing dependable.

Jim

Reply to
RST Engineering

With a small solar panel to keep the continuous load going, not a bad way to go.

Jim

Reply to
RST Engineering

"Hefty" solar panels don't come for cheap.

Do you have regular enough w>After much thought and ponderance, I've come to the conclusion that to

...Jim Thompson

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|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
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Reply to
Jim Thompson

First, check on that price again. One thing I learned a while back is, that while that is THEIR price, if you go to an electrical contractor and get a quote for the same work for less, they have to match it! You can save big bucks that way. The only part they HAVE to do is mount and connect the meter. All the rest you can get your own electrician for.

If you want to go solar, make a single closet like room, with venting directly outside. Don't use truck batteries, you need deep cycle types. You still end up doing all the wiring from hangar to hangar, and the solar cells and batteries aren't cheap. Neither is the inverter. There might not be as much of a diffence as you would like.

Charlie

Reply to
Charlie Edmondson

I use Trojan T-105 6 volt batteries in my 5th wheel. They are far and away better than any automotive or deep cycle 12 volt battery for even several times the price. A friend not far from here has a solar setup like you are contemplating at his hangar. I also have a solar panel on my camper. Here's a couple of links to get you started. You don't have to worry about hail, until it comes down the size of softballs they are impervious to it. I don't know what problems you mean with paralleling batteries but as long as all the batteries are the same they charge just fine. Just make sure you have a charge controller. Mine is a 7 amp because I only have a 75 watt panel. A few hundred watts and about six

6 volt batteries would take care of you.

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RST Eng> After much thought and ponderance, I've come to the conclusion that to

Reply to
Newps

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reasonable

Seems running a generator would be simpler and cheaper.

Reply to
Dave Stadt

I have no experience with solar so I can't comment. However, I'm wondering if you have considered a small gas or diesel powered generator? It would likely be cheaper initially and less maintance over time, especially if you don't need the power all of the time.

Matt

Reply to
Matt Whiting

The generator can provide battery charging capability should the sun or wind let you down.

to

Reply to
Dave Stadt

It could be done, but you'll spend about $8-9 a watt with no rebates cause your not grid connected.

Vist the homepower news groups. Or

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You'll need a generator backup, diesel preferred.

Calculations for Autonomy, days with out sun.

Calculations for collector plate angle, for winter months.

Possibly a licensed electrician to install. Depends on local codes.

All systems are only %70-74 of their actual panel ratings, So keep this in mind. (its an efficiency thing)

And probably a large 1000's of amp hours battery bank to meet the autonomy specs. Assuming 8hrs for lighting, 2K @ 8hrs (24v) is 666AH, usually Autonomy is 4-5 days. So your looking at 2000-3000 of AH battery capacity. (no cheep truck deep cycles here) Plus you'll need to charge them with the PV's ;D.

Cheers

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Martin Riddle

"RST Engineering" wrote in message news:80d06$43a0a4a3$42513b5b$ snipped-for-privacy@DIALUPUSA.NET...

Think about a modest solar system for lighting only and a generator for the rest. I have 100 watts of solar panels and a small charge controller that easily runs two 60 watt-equivalent compact fluorescent lamps that have been lighting up my yard every night for the last several years. The battery bank for that little solar system doubles as the starting battery for my generator. One of those pad-mounted generators you see at Home Depot could easily handle the machine shop tools and would probably only see a few hours of use per month.

To get an idea of solar prices, try here:

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Vaughn

Reply to
Vaughn

The economics still aren't there for solar in most situations unless PG&E has a high minimium monthly bill. The place to same money here in Sandpoint is on sewer and water. The connection fees are high and the minimium bill is about $40. One well and one leach field could serve numerous hangers.

Mike MU-2

Reply to
Mike Rapoport

Jim,

Check out

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They have a store near you and also catalog that is very informative on sustainable, off-grid living and systems.

Mike MU-2

Reply to
Mike Rapoport

I've had my reservations about RG ever since they endorsed those piezoelectric washing-machine tablets.

More than anything though, CE/UL-approved grid-connect inverters (ok AND EU subsidies, especially in Germany) are helping to increase cell and panel manufacturing capacity. Which is essential to driving down cost. I think off-the-grid is fine for hangars and folks in Idaho with acres and acres of acres, but grid-connect is where the volume is.

Don

Reply to
Don Tuite

The hangar doors have the Armstrong opening/closing mechanism.

Jim

Reply to
RST Engineering

Hey Jim, Check the cruising boat and trawler chat groups... THey have off the grid down to a science.. Solar cells to keep your battery set charged and a generator for surge loads... Better yet, is a DC alternator on your truck for charging the batteries adn doing welding on the side.. see here

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denny

Reply to
Denny

Hey Jim,

Try looking through this.

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My son has provide me some literature on renewable energy and I am convinced with some up front spending you can survive anywere without the power grid. You may need a 5KW generator at time when the wind, solar, etc give out.

------------- Regards, Ross C-172F 180HP KSWI

RST Eng> After much thought and ponderance, I've come to the conclusion that to

Reply to
Ross Richardson

Clever idea. Good luck with it.

Are the hangar doors electric? If so - make sure you have enough surge current capability to get the motor started. I have a 120V /

1850W generator and it did not have enough juice to raise the door during a power outage.

-Nathan

Reply to
Nathan Young

yes, thats when solar pv starts to look good.

There are 2 main invertor options, sine or modified sine, which is IRL rectangular wave. IIRC, iron fl ballasts and motors can overheat on MSW, so all your apps ideally want sine. However MSW is much cheaper, and there are workarounds. Fl lights can be run at just slightly reduced power, or heatsinks added to the ballasts, etc. Electronic ballast lights would run happily on 150v dc. Motor driven tools would be fine as is unless youre running them to where they already get seriously hot, ie heavy use. There are ways round it if it proves to be an issue.

ok, first with those powers it would make more sense to run your battery back at apx 150v (assuming you want 110v ac) and use a simple chopper to produce the ac. Your output will then have unregulated V_peak and regulated constant rms. That should work for all your loads.

You should add a parallel diode across each battery cell, so that one cell going down has little effect on system performance, and enables everything to continue running. Ditto with the panels, there its particularly important to have a diode across every panel when youre running them at HT.

This avoids parallelling batteries (not that thats needed anyway), plus reduces cost of invertor and wiring. Also it means you can supply 150v dc to mains CFL bulbs, electronic ballasted fl lights, and anything else that rectifies the mains, again cutting down on system cost and improving reliability. Use a different plug/socket type for the dc supply.

One way to shave 10-20% off power consumption would be to up your supply frequency slightly, this would work nicely with magentic ballast lights and brushed motors, but not induction motors. FWIW brushed motors can run on dc anyway - but not @ 150v.

Solar pv is cheaper than wind, and has less significantly issues, so I'd stick to solar.

Battery case is vented to the outside.

alt.solar.photovoltaic is the place to go.

Also dont overlook simple ways to cut cost. A minimal cost reflector outside a window can be used to increase daylight levels, and delay lighting dwitch on until later in the day, thus reducing system cost. And of course a switchbank for your lighting will enable you to use the lights only where theyre wanted at the time. No sense lighting the whole place up bright when youre only working in one area.

And dont forget batteries dont last forever, you need to account for future replacement. Beating your PG&E costs should not be difficult, as long as its designed competently.

NT

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meow2222

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Michelle P

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