Price of Solar! WOW

CA Traveler wrote:
Almot,

Please tell me I won't regret taking your advice. :B

But the die is cast with 3 panels and 10 ga wire purchased and installation just started.

You mean "...not taking my advice". Of course, you will :), because there is no such thing as too much solar. What you are doing, is what SMK here did, with TS 60, as I recall. Worked for him, will work for you.

KMLsquared wrote:
BFL, could you expand on why you would prefer the PWM? I was beginning to lean towards MPPT due do the fact I camp all year around northern ca and I want to flat mount panels on the roof. I have gathered that the MPPT works better in less than optimal panel aiming conditions. Am I way off base?

My situation is different from that so I don't know what would be better for that.

I had two 12s last year with PWM and got the panel's full amps so I was happy with that. Then this year I tried it with one 230w panel and MPPT thinking I would get more amps than with the PWM. I did in April-May when it was cool, but by June it was warmer and now I was getting fewer amps with the MPPT than I would have with PWM. Turns out that panel heating loses voltage so you get fewer amps the way MPPT works. With PWM you don't get that reduction in amps with hotter panels. Difference was PWM 14.5a, MPPT cool 15.5a, hot 13.5a

So on average I would do better with a steady 14.5 instead of mostly 13.5 for the time and location we use solar. However there are many other factors in what to chose like price, roof real estate, etc etc.
Man-handling as portables another thing.

As it is, we have enough solar anyway even with the 13.5 so it is no big deal for getting by or not, and it was less money for the 24v and MPPT in this case than the more expensive 12v panels would be, thanks to the MPPT controller only costing $102 instead of $300 or whatever.

I don't know about that low/indirect light advantage for MPPT. Haven't noticed it but others swear by it. I do aim my panel during the day, if that makes any difference.

BFL, could you expand on why you would prefer the PWM? I was beginning to lean towards MPPT due do the fact I camp all year around northern ca and I want to flat mount panels on the roof. I have gathered that the MPPT works better in less than optimal panel aiming conditions. Am I way off base?

The Eco-w didn't close any gaps, it filled a void. When it came out not only was there no inexpensive functional 20a MPPT controller. There was no 20a MPPT controller at all. You had the choice of the MS 15a for $225 or the Rogue 30a for $325. Now you can get a Rogue 20a for $250 to run the same single $150 solarblvd panel a Eco-w does.

As far as carrying the cargo, if the features the Eco-w has fits your needs, it's proven to do what it says it will. Our "affordable" 720 watt system will give us all the comforts of home and we wont be using a fraction of the power it's capable of.

wintersun wrote:
Problem with that is the ones used for buildings are much larger than the available space on most - RV's. The Kyocera 140 Watt is probably the best selling RV panel and what makes it attractive is its narrow width. It can fit in spaces and not be shaded by something else on the roof of the RV.

Well there has been a consistent bias on these boards towards mounting smaller panels closer to the roof and "Damn the shadows - Limited power ahead".

I've photographed several installations with raised panels. My installation will be shadow free in the summer from 6 AM to 6 PM regardless of rig orientation but what do I know as I've only installed one small system on my son's 5er? My panels will either blow off the roof or be rock solid. And you bet I have a backup plan JIC.

KMLsquared wrote:
KYOCERA SOLAR PANEL 120W 12V $99
http://sfbay.craigslist.org/nby/eld/4716352370.html


Since this is a cost thread, is this a good deal and are these good panels?

I try to do as much reading and learning as posable but my head just turns into mush!

That is an excellent price for those 120w panels, and they are quality panels if there is such a thing. (If it works at all it is good AFAIK, but some claim to be higher quality, whatever that means)

So if such panels are what you want/need, and there is no shipping (you pick up) then IMO grab them.

Some dealers here say solar panel prices will go up next year due to higher material costs to make them, if for no other reason such as currency exchange rates.

Operationally, in my situation, I would rather have two 120s and the Solar30 in PWM than my 230 and Eco-W MPPT, but last year when I got the 230, it was because it was much cheaper to go that route where 12s here are twice the cost of 24s.

If they were near the same price, that would open up the options. Too late for me now. I will live with what I have since it works well enough, but it is not what I would really prefer.

Almot,

Please tell me I won't regret taking your advice. :B

But the die is cast with 3 panels and 10 ga wire purchased and installation just started.

Surely with next summers sun I'll be a happy camper I hope.:)

wintersun wrote:

JiminDenver wrote:
You might try calling some solar installers in your area and seeing if they have any left overs. Many order a extra panel or two per project but don't want to go thru the hassle of selling them.

Problem with that is the ones used for buildings are much larger than the available space on most RV's. The Kyocera 140 Watt is probably the best selling RV panel and what makes it attractive is its narrow width. It can fit in spaces and not be shaded by something else on the roof of the RV.

Hey, if they fit they fit. That's a requirement of any panel isn't it? If the big panels do fit, they can make a inexpensive powerful system.

KMLsquared wrote:
KYOCERA SOLAR PANEL 120W 12V $99
http://sfbay.craigslist.org/nby/eld/4716352370.html


Since this is a cost thread, is this a good deal and are these good panels?

Er... a 24V "cost thread", probably. At least, this is what the OP started. So let's not deviate. But, yes, ~$1/W is normal or good for 12V panels. The best way to stop your head from turning into mush is to stop thinking and start doing. Make cardboard templates of this panel size, or a 24V panel (220 to 250W are all same size), and see what fits.

pianotuna wrote:
Hi CATraveller,

I do series parallel for an input voltage of 33 to a Blue Sky 3024di controller. It works well.

I think Don is onto something here.

CA - here is what I would do (and there are, of course, other solutions). Get 4*240 or 4*250, as you already planned, and TS 60. Wire panels in series-parallel. Then you will have a manageable 17A to controller at 64 Vmp. Plug and play, with MC4 connectors all the way, no rooftop box, no monstrous #4 cable. Just make sure that the final cable from roof to controller is #8, not #10 or #12. Unlimited Solar have MC4 #8.

SMK here has 750W with all-series MC4 #10, and it works for him. I have 500W series with MC #8 - after running the numbers I wasn't even sure that should pay extra few bucks for $8, as at 9A the difference in V-drop from #10 was negligible. You will have enough pains planning and putting it all together as it is, why making it more difficult.

KYOCERA SOLAR PANEL 120W 12V $99
http://sfbay.craigslist.org/nby/eld/4716352370.html


Since this is a cost thread, is this a good deal and are these good panels?

I try to do as much reading and learning as posable but my head just turns into mush!