Will this solar system suffice?

jrnymn7 wrote:
2solar.ca

no idea how much for shipping... but pay my gas and I'll deliver them to ya. o.k., just kidding, but i really do want to head out to bc at some point :)

Not sure what's going on, if they're still in business or not?
2solar.ca

Their prices seemed good though, are their panels any good? (Found a link to their prices on FaceBook)
prices

THey sau made in Ontario but the name on the back is Sunbe which looks to be made in China?
Sunbe

Hi,

The inverter is going to dwarf all the other loads. Count on at least 50 amp-hours per day for it.

Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!
solar spreadsheet by N8GS

raztec wrote:

4. Inverter to charge my computer, cell phone, cameras about 4-5 hrs/day.

300w of solar Wil avg 15~18amps at solar noon, if the batteries can accept it
Cloud effect fringe lensing peaks might it 20~22 but only momentarily
New panels will sometimes show a peak above rating on good days
Buy that's only during the "as new period" , after a while they settle down

pianotuna wrote:
start by doing an energy audit.

Good point. I'm not sure how to do that but I probably should get a little more than I need.

Here's what I would use for about 10 days off grid.

1. 2 lights for about 4-5 hours.
2. Furnance depending on temperature q hourly
3. Fantastic fan 2 hours/d
4. Inverter to charge my computer, cell phone, cameras about 4-5 hrs/day.
5. Water pump for sink and shower. Average 40 minutes/d
6. Some form of external water pump to fill my clean water tank (only 30gal) from stream or lake at least twice in 10d.

Thanks for any advice you guys can provide.

start by doing an energy audit.

1) For pwm, you want parallel. pwm basically passes thru the amps, so you want the most you can get... in parallel, amps are added, in series volts are added. With mppt you want series and high volts.

(pwm can be used 12v panels to 12v bank, or 24v panels to 24v bank... but not 24v panels to 12v bank.)

2) either or... it's up to you. if you think you'll need to squeeze every ounce of energy out of the array, (especially spring and fall), go mppt. If mostly summer camping, pwm will work well... in fact, in hot weather, pwm does near as good, if not better (which is still up for debate). :)

3) wire for parallel to be safe... then you can do either. for only 10', panels to controller, personally, i'd go 8awg, but others will likely say 10awg... (I'm not a fan of voltage drop), and it will allow for any future adding on.

4) I like the trimetric, but I think there are cheaper alternatives. An Amp Hour counter is a must have, imo. No idea how the ms meter would work. I know on the tracer, it has no idea what the soc of the bank is, although it likes to pretend it does... but I didn't buy it for monitoring soc, anyway.

5) can't advise you on that. I have a metal roof, and will be using sheet metal screws and butyl gasket.

Also, for 300w, you'll see ~20a thru the pwm controller. You need to allow for another 20%, so 24a... so you need at least a 30a pwm.

And if going with mppt, you need one with a high enough Voc rating to handle those 150w/12v's in series. (panel Voc x2)

pianotuna wrote:
1. your choice will determine whether you use a pwm or mppt controller (series = mppt)

Any suggestion on whether to go series or parallel for this system and my usage?

Thx

1. your choice will determine whether you use a pwm or mppt controller (series = mppt)
2. yes
3. depends on #1
4. no
5. no holes needed on a fiberglass roof. 3m has an adhesive. With a rubber roof holes required.

jrnymn7 wrote:
raztec,

Wire size will depend on length of run and amount of current running thru them, be it from panel to controller, or controller to bank. When running two 140w/12v panels in series, thru 50' (one way) of 6awg, to mppt cc, I see very minimal voltage loss... less than a third of one percent. In parallel/pwm, that would be 2-3x the loss, as amperage from array would be 2-3x that of series/mppt.

Thanks for this. A few more questions:

1. So should I install the two 150W panels in series or parallel?
2. For that kind of wattage wouldn't a PWM controller suffice? Or should I spend the extra and get an MPPT. The max wattage I'll ever be able to upgrade to probably 600W. But not sure with my usage and limited battery space I'll ever need that.
3. Considering a max of 10 feet to the panels, what gauge wire would I need from panels to controller and from controller to panels?
4. Is a battery monitor like the trimetric really necessary or can I simply use the morningstar controller which comes with some kind of monitor?
5. Do I have to drill holes in the roof, or can some industrial strength glue/sealant hold the panels in place?

2solar.ca

no idea how much for shipping... but pay my gas and I'll deliver them to ya. o.k., just kidding, but i really do want to head out to bc at some point :)