Advice for minimum requirments to build starter PV system.

[Rex Mundi]

I have been interested in setting up a small PV system to attach to a
gardening shed to provide light and maybe a small fan and/or radio. I
don't want to have to run power to the shed and I want to use this
setup to test the waters for more PV independence down the road. What
are the minimum items I will need to set up a small system, besides
panels and batteries?

 

[Vaughn Simon]

I have been interested in setting up a small PV system to attach to a
gardening shed to provide light and maybe a small fan and/or radio. I
don't want to have to run power to the shed and I want to use this
setup to test the waters for more PV independence down the road. What
are the minimum items I will need to set up a small system, besides
panels and batteries?

At minimum, you need to add a solar charge controller to your equipment list.
In my similar small system, I use 13 watt, 12 volt compact fluorescent lamps
rather than dealing with an inverter. I buy them at West Marine. They are
pricy, but they last me several years in daily use.

My system lights the front and rear of my house, and keeps my generator
battery charged.

Vaughn

 

[Eeyore]

I have been interested in setting up a small PV system to attach to a
gardening shed to provide light and maybe a small fan and/or radio. I
don't want to have to run power to the shed and I want to use this
setup to test the waters for more PV independence down the road. What
are the minimum items I will need to set up a small system, besides
panels and batteries?

What's your estimate of the number of watts you need and for how many
hours a day ? You can't intelligently design a PV system without that.

Also it's important to know where you live to check the insolation data.

Graham

 

[Eeyore]

I think you'll need some disconnect switches. You'll need one so you can
turn off power from the panel.

He said he didn't want to run AC to the shed.

Graham

 

[Eeyore]

There is no need to test the water. Solar will run your shed, and yes,
it can even run your house.

At a vast cost of course.

Graham

 

[Vaughn Simon]

There is no need to test the water. Solar will run your shed, and yes,
it can even run your house.

Your best bet is to learn the correct formula for sizing and design of
systems.

Perhaps, but my system is still waiting for me to whip out my calculator.
Meanwhile, it has been chugging along for about the last 6 years with nary a
problem. It was really quite simple: I started out with an old 70 watt panel.
(70 watts 'cause that was the one I was able to scrounge.) Then I bought an
appropriately sized charge controller (still no calculations). I have 2 amps of
load for 4 hours a day. (8 AH. I can do that calculation in my head) My
generator battery (80 amp hours)can easily handle several days of autonomy and
still have enough left to crank my battery.

This is not rocket science.

Vaughn

 

[Vaughn Simon]

I think you'll need some disconnect switches. You'll need one so you can turn
off power from the panel.

Here, I use an automotive style 2-pole flat connector rather than a
switch. The connector is appropriate to both the current load and the semi-damp
environment.

You'll need another to turn off power from the battery.

Again, I see no reason for a switch, but I do have a fuse in the line which
serves as both my maintenance disconnect and as overcurrent protection.

Vaughn

 

[Eeyore]

"Eeyore" wrote

Sorry. That should read "solar panel".

OK.

Graham

 

[Rex Mundi]

On Thu, 29 May 2008 15:37:00 -0400, Rex Mundi <[email protected]>
wrote:


Thanks for everyone's suggestions.

 

[Ulysses]

for the light how about getting a couple of those garden
lanterns, put them on the roof, and rig the LED lights inside
the shed. For under 20 bux you could see what you stubbed your
foot on when it is dark out.

peace
dawg

They also make pretty good AA chargers (if you get the kind that use AA
batteries, of course)

 

[Ulysses]

At minimum, you need to add a solar charge controller to your equipment list.
In my similar small system, I use 13 watt, 12 volt compact fluorescent lamps
rather than dealing with an inverter. I buy them at West Marine. They are
pricy, but they last me several years in daily use.

I've not seen lights such as you described but I have used some CCFL lights
that use two 12" tubes that came from www.elwirecheap.com. They used around
1/2 amp compared to about 2 1/2 amps for a regular 12 volt incandescent bulb
and take about a minute to warm up. I did have an inverter fail on one and
I think it was caused by overvoltage from an RV 12 volt converter. In any
case the lights, including the inverter and two tubes only cost around $12
and I think that was including shipping. This one says it's for a computer
but I think it's what I got but you might want to check the input voltage:
http://www.elwirecheap.com/du12cokit.html. I don't know where the prices
went.

 

[Vaughn Simon]

I roofed my shed with clear polycarbonate panels from Home Depot on
the north side and use a little solar shed light from Harbor Freight
to light it at night. The PVC roofing panels are cheaper but break too
easily.

Some of them also seem to suffer from UV exposure, curling and becoming
brittle after a year or two. While not specifically designed for the job and
more expensive, clear plastic hurricane panels would last much longer.

Vaughn

 

[Vaughn Simon]

On May 30, 10:40 am, "Vaughn Simon"

Well, just like wayne you have told us what you have but not what it
actually runs, sounds like a single 20W globe.

Well, you have compared me to someone I don't even know, and you have made
(wrong) assumptions that you did not need to make about my system...

I am sure everyone is impressed.

Now you have made assumptions about how "everyone" must think about my
system.

Do you suppose that I was trying to "impress" someone? ...or do you suppose
that I was trying to make a point about a system that is very much like the one
the OP is contemplating? Interesting how you ignored the thrust of my post and
tried to change the subject.

Bye.
Vaughn