Noob with a big problem...

[M153Ry]

Okay where to start... Well I guess here is as good as any! So my parents approached about making a "Solar dIy System" for their home. What I'm working on is trying to design the system so I can price supplies. For the sake of saving me from messing up the numbers I'm just going to say I'm making 4kw (180-200 watts over) worth of paneling. Which comes to a nice whole 10 panels. So being an art student I feel like I'm stuck in the proverbial "Rock &a Hard place".

Here's where I'm at with my panel layout:

Panel size - 4'x8'
Polycyrstalline Cells - 6"x6"

That's 105 cells per panel equaling about 420 watts per panel

Things I'm sure I need:

Inverter - unsure on size
MPPT
Charger Controller - unsure on size
2 switch boxes
3 inline fuses

So here's where I get lost....
>.>
<.<
???

I'm guessing I want my panels to be an output of 24 volts right, and once I'm outside the j-box can I run everything in a 220 line or do i need another type of wire? Am I forgetting anything, doing anything wrong? Any type of help and support on my adventure is greatly appreciated!

~M153Ry~

[Mike90250]

Whoa! put the brakes on.

Any DIY panels you build:
a) are from 2nds and failures from the production lines. There are no prime cells on ebay,
it's just that mere mortals do not have the gear to test all the many ways cells can fail

b) DIY panels are not UL listed, and cannot be placed or connected on any insured building,
or connected to a Grid Tie system

c) the sheer physical size of a +400watt panel is too huge to move safely. I don't know of any
commercial panels this size - maybe there is a good reason.

d) the problems of building and sealing (vapor tight seal, not rain tight) panels at home
are way underestimated. DIY panels last a couple weeks to a year. The first warm spring after a
rainy season usually will finish them off.

e) the issues of 600V rated components and their construction is beyond 99% of well equipped DIY
workshops. I think the new standard for panel isolation is now 1Kv.

For a grid tie system, you need to look at a couple years of electric bills, to get an idea of how much
panel you need to offset a major portion of your electric bill. Then, if you are in a low sun area, and have cheap electric rates, you may never get the system to pay back itself.

If your parents are on grid, it's pointless to go "off grid" because any quick estimate will show their
electric bill (batteries, inverter, controller, mounts, pv panels) will go up at least 10x what they pay for grid power. (unless you donate $40,000 worth of gear to them)

[Sunking]

Do not even bother with making the panels. You can buy them cheaper and they can actually be used as part of the house wiring. A DIY panel is not listed and cannot be used as part of the house wiring system.

Secondly if th ehouse has commercial power, you will not be going off-grid battery. To do that is foolish as the power will cost you some 10 times more than buying it from the power company, nor does it qualify for any incentives. If your parent use an average 30 Kwh per day they are looking at around $90,000 initial cost to install with $30,000 of that being in batteries that need replaced every 5 years.

Go read this stickie and you will see what you are up against. Once you have read that one try this one.

[M153Ry]

My statements in bold

Whoa! put the brakes on.

Any DIY panels you build:
a) are from 2nds and failures from the production lines. There are no prime cells on ebay,
it's just that mere mortals do not have the gear to test all the many ways cells can fail

this is true but with a muitimeter I trest and replace dead cells

b) DIY panels are not UL listed, and cannot be placed or connected on any insured building,
or connected to a Grid Tie system

they don't want a grid tie system because if they ever decide to move thats more work and the paneling wont be place on the house they'll be mounted in the yard

c) the sheer physical size of a +400watt panel is too huge to move safely. I don't know of any
commercial panels this size - maybe there is a good reason.

I'm on of 4 boys so with four sets of hands I believe a 4x8 panel can be moved safely

d) the problems of building and sealing (vapor tight seal, not rain tight) panels at home
are way underestimated. DIY panels last a couple weeks to a year. The first warm spring after a
rainy season usually will finish them off.

I do see what your getting at here

e) the issues of 600V rated components and their construction is beyond 99% of well equipped DIY
workshops. I think the new standard for panel isolation is now 1Kv.

For a grid tie system, you need to look at a couple years of electric bills, to get an idea of how much
panel you need to offset a major portion of your electric bill. Then, if you are in a low sun area, and have cheap electric rates, you may never get the system to pay back itself.

this was already which is why we decided on a 4kw worth of cells

If your parents are on grid, it's pointless to go "off grid" because any quick estimate will show their
electric bill (batteries, inverter, controller, mounts, pv panels) will go up at least 10x what they pay for grid power. (unless you donate $40,000 worth of gear to them)

so what your saying is it would be more cost effective to buy a kit then?

[russ]

Buy factory built panels - you save time, money and have a better product.

[inetdog]

this is true but with a muitimeter I trest and replace dead cells

Actually, since you are dealing with factory seconds or untested fallouts, all you can do is separate the dead cells from the merely bad ones. (Low output current, poor life expectancy, etc.)
A panel made from selected bad cells will not last as long or perform as well as a panel made entirely from good cells.
A multimeter is not enough to do a complete test!

[Sunking]

4 boys to move a 9000 pound battery. Good luck with that.

You need to listen. This project is not going to happen. You have no idea of the cost involved or the logistics. READ THIS PART CAREFULLY. You cannot use DIY panels as part of your homes wiring. They are not listed for that purpose.