Solar Panels - where to start?

n/a - vanity ^ | 10/9/2008 | me

[Libertarian4Bush]

hi. I'm looking to start experimenting with solar cells - just enough juice to perhaps power (potentially at a later time) a lamp, a laptop dock, 2xAA battery charger, or, at its most ambitious, a desktop PC.

where do I start?

any advice would be appreciated, including where to reliably get them at a decent price.

[listenhillary]

I had seen a 5 watt? 15watt? at Harbor Freight for about $130. Sorry it has been awhile.

[eXe]

Here is how I did it.

4 Walmart Deep Cycle Batteries (I added a battery since this pic was taken)

2 75 watt Kyocera Panels

A Xantrax C40 charge control

And a Xantrex 1500 watt inverter

Runs most anything I need in an emergency, and is really handy for my garage door as well when the power is out.

I also have a second smaller system that has 2 50 watt panels and 2 deep cycles with a 1000 watt inverter, that would probably do exactly what you want and you could scale it up when you nee more later.

here is a pic of my backup power setup (which has been tested many a time and used for ham radio emergencies as well) in my garage

[listenhillary]

http://www.solarwellpumps.com/?gclid=COKFwc_Vm5YCFSASQQod3Qyb7Q

[Chickensoup]

AND I live in Maine.

[JRandomFreeper]

It does matter. P=I*E. Well=10.2A*240V = 2448W. If your well pump runs an hour a day you need about 3KWH. If you use 12 volt panels, that's about 31 Amps input for 8 hours.

Your fridge uses P=I*E Fridge=12A*120V = 1440W. But the power factor is probably about .8 for your fridge, and the duty cycle depends on how often you open it (how long does it run every day?), and where you place it.

I have generator backup to feed my battery bank, but in practice, I rarely use it. I have run a PV system for over 5 years in real service. I spent a lot of time with spreadsheets setting it up.

/johnny

[DelaWhere]

While I have not bought solar items from these folks yet - everything I have bought from them has been first rate and excellent service...

href="http://www.northerntool.com/webapp/wcs/stores/servlet/category_6970_770399+6228">Northern Tool Solar

Solar is on my 'to do list' for this coming year...

[JRandomFreeper]

Surplus telecom batteries are cool to have, if you can move them. I have 3 GBC batteries that weigh about 400 lbs each. You can hook them up however you like to get 6/12/24/36VDC. I get 1200AH at 12V to feed the Trace inverter from that bank.

I paid less than $100/battery, and they have been in service for > 5 years.

I use an engine hoist to move them.

/johnny

[OneWingedShark]

Nice!
Where’d you get them?

[JRandomFreeper]

How do I obtain this information.

If you can determine the manufacturer and model of your well pump, you have a base-line that is usable (but wrong) for current draw (amps) and power factor. Finding out how long it runs per day is less trivial. I have old drum recording gear that can measure how long the contactors are closed, but that's antique stuff that most folks don't have. It could be derived from the GPM the pump delivers vs your average, max, and mean daily use (if you meter your water).

Or you could hire a jouralism major to hit the button on a stopwatch everytime the pump runs and average it out over about 10 months. But that's a long time near a liberal.

You need to date Red Green. He'd fix it with duct tape.

/johnny

[Kevmo]

bmflr

[JRandomFreeper]

Friend of a friend that was doing de-commissionings of fixed plants. But get word around that you are looking with the radio/telecom community, and check e-bay, and you will find something.

Caveat emptor. Take a volt meter. I rejected two batteries that had dead cells.

And be careful moving them. Cardboard/fiberboard/cardboard layer duct-taped over the connectors makes transporting them less hazardous.

That amperage can WELD. It would suck to have a battery slide into the side of your truck, short out, and make a pool of molten sheet metal over your gas tank.

Really suck. That would be a Bad Day(tm).

/johnny

[Chickensoup]

But that’s a long time near a liberal.

Very Very funny!

I dont know who Red Green is but no one dates 55 year old women.

So again, FreeRepublic is my husband. Thank you for the information.

[JRandomFreeper]

http://www.redgreen.com

He ain't right, but he's close enough to be a role model. Give me enough duct tape, and I can fix Wall Street.

/johnny

[Titan Magroyne]

You can check the article archives here:
http://backwoodshome.com/
where they’ve written up a detailed installation or two. There usually is a PV pro involved no matter how much homework the prospective off-gridder has done, though that may be only for liability reasons.

Great magazine, I just don’t have the reading time that I used to. Or now that I have the time, I have to pinch every penny...

[Nailbiter]

interesting thread

[Daffynition]

Welcome to the opening of our "Solar Reading Room" ...just a little sunlight each day to evaporate waste ... unlike a traditional composting toilet ...

[thackney]

My interest is in emergency use. Able to get potable water to drink and use in emergencies

I am an electrical engineer. The problem is the amount of power needed for the pump to run, not so much the amount of energy needed per day for a minimal water usage.

The pump compared to many other electrical items in your house (except an Central Air Conditioner or Electric Oven) is that it draws a lot of power when running, even if it only runs a short time.

You have to build a system capable of delivering that large amount of power during the run time, even if it only operates for a few minutes per day.

My estimation is that you would be far cheaper buying an additional water tank (and double check valves to keep from losing the water back down the well) than to build a Solar power system large enough to run a pump for a few minutes a day.

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&langId=-1&catalogId=10053&productId=100086226&N=10000003+90401+500997

A small gasoline generator would be a much cheaper solution as back-up power for the other small stuff. Solar is too large of a dollar investment for a use once or twice a year.

[Chickensoup]

Thank you. There are very few people out there that I have found who can answer these sorts of questions. It is sort of a beteen field.