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.

[Libertarian4Bush]

thanks!

[Chickensoup]

I have been reading about it because I am interesed in enough to power my well and a refrigerator and freezer.

[11th_VA]

Solar to electrical power conversion is the least effective transfer of energy, unless you need rhetoric to win an election ...

[Libertarian4Bush]

that’s great, but does little to quash my scientific interest, let alone my need to fiddle with stuff until I break it.

[Libertarian4Bush]

well - what have you learned? :)

[FastCoyote]

[I have been reading about it because I am interesed in enough to power my well and a refrigerator and freezer.]

First, start with a checkbook filled with a couple thousand dollars.

[JRandomFreeper]

Learn some formulas. E=I*R (voltage=amps*resistance) where E is volts, I is amps, and R is ohms.

P=I*E (power=amps*voltage) where P=watts.

And there are several others, especially if you are going to run AC devices via an inverter.

A technician class radio operator licence will give you enough information to be clueful about the math. And you gotta have the math.

Good luck with learning about PV. I am almost off the grid at this point. It's worth learning, and you meet some cool folks. Smart folks. Not liberals.

/johnny

[AbeKrieger]

The efficiencies with solar will (I believe) prove to be heat energy rather than photovoltaic. For example, a mirror dish focusing heat onto a point that powers a Stirling engine or the like.

As it stands today it is impossible to get value for the money on photovoltaic. It will never pay off.

[Libertarian4Bush]

yay - we get it. I’m not asking for a tax break, or a carbon credit, or even a cookie from Al Gore.

I’m not asking for a referendum on solar power vs other forms. I’d simply like to keep something off the grid, and I don’t think PA will give me a permit for a fission reactor.

[Chickensoup]

Have set money aside and have read quite a bit.

Dont want to change my well pump, but do want to be able to run it.

[JRandomFreeper]

Forget the well, unless you have $$$s. The reefer and freezer are easy. I support those (and a few small intermittant loads) with 3x120w panels, 1200AH of batteries, and a Trace inverter. Duty cycle is important for that, so place your reefer/freezer in a cool spot.

/johnny

[InterceptPoint]

Here is a link to video I made recently of a full up 40 panel, 8.4 KW solar installation. These panels put out about 200 to 250 watts at maybe 10 volts and cost about $700 to $1000. You would need some sort of converter to get the AC or DC voltage that you needed. These are photovoltaic panels that are pretty much standard for high end systems. There may be less expensive solutions. Shop around.

Here is the link to the video. Make sure you click on the "Watch in High Quality option".

Solar Installation - A Tough One

[Chickensoup]

Backwoods solar has a good catalog

That now there is a certification in solar intallations

That few electricans know anything about it

That I wish I had a man around the house who like to do this so I dont have to figure it out by my self lol

That it is complicated and expensive. I thougth I would jsut target a couple of items. I need water, and refrigeration. Everything else is optional

[Libertarian4Bush]

Good luck with learning about PV. I am almost off the grid at this point. It's worth learning, and you meet some cool folks. Smart folks. Not liberals.

thank you! as for being off the grid, I'm not nearly THAT ambitious... but that's exactly what I'm looking for - nerd camraderie. ;) math is a strong suit of mine, and I'm comfortable with electronics, but my bigger questions revolve around STORING the power, using it later, and possibly even using it as a supplement to the electric company.

[Chickensoup]

Why is the well so difficult?

340 feet drilled

pump at a little more than halfway.

[JRandomFreeper]

As part of my real job, I was required to do some research for Y2K work-arounds, as part of my avocation of ham radio, I worked with other radio operators to research emergency power, and because I hung out with some "survivalist" (what's the opposite of that?) kooks, I studied the inverters pretty hard.

Trace makes some of the better equipment. And it's safe, and pretty stupid proof.

If you use the square wave inverters, clean up the AC before it gets to your transmitter, or you will be out of FCC regs.

/johnny

[JRandomFreeper]

Why is the well so difficult?

a)Most well pumps are 240VAC. Inverters for 240 volts are much more expensive.

b)Wells consume a LOT of power, but the duty cycle is variable. That means a lot of batteries and panels.

The first step to to make some measurements. How many minutes a day does your well run, average, peak, mean? How many HP is your well pump? W=770*HP (roughly). What is the power factor of your well pump? Answer those questions, and you can start to engineer your solar power system.

/johnny

[mojo114]

I see you are in the Northeast, I am also. The back of the house faces West and gets full sun. I have talked about solar for year’s but, husband, who studied solar energy back in the 70’s as a mechanical engineer, continues to think that solar is not going to pay for itself.
If you check with your State you may be able to receive tax benefits to out way the cost of adding a solar panel or two, however, it is expensive.
Heck, we have visited California, the Carolina’s, Florida and Las Vegas recently and I have seen very few houses with any solar support.

[Chickensoup]

I am not sure. How do I obtain this information. It must have come with the house.

My interest is in emergency use. Able to get potable water to drink and use in emergencies, not for daily showers.

[raybbr]

b)Wells consume a LOT of power, but the duty cycle is variable. That means a lot of batteries and panels.

Mine runs at 10.2 amps and is set 400 feet deep. The 240 part is the issue not the power. My fridge is 120 and is rated at 12 amps.

Better off with a generator for emergencies.

How heavy are the panels?

[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.