New Member wanting to put in SunPower System..is this a good deal?

[Naptown]

I was told I could not expand with an inline inverter that is why the guy with SolarWorld told me to do the micros? Do you think there is room in the SunPower bids to get it a little lower or doeSunPower not negotiate?

So with the micro inverters you would be able to add a grand total of maybe depending on how they wire things 4 panels to your system before you got into rewiring.
You can always expand but it will mean adding an inverter. I do not suggest getting an overly large inverter now but wait till you need to add on and add one.
Besides with the Solarworld panels taking up every square inch of roof where could you expand anyway?

[J.P.M.]

So here are my recent proposals. I'm planning on mounting on the front of the house since I have pool solar on the back.

Reputable Company
18 SunPower Panels NE-327 All Black
Size 5.89
Production monthly/annual = 883/10,595
SunPower Inverter SPR-5000
$21,887

Reputable Company
21 SunPower Panels 327 NE-Wht (Not as attractive)
Size 6.86
Production 10,020 annually
Inverter PowerOne PUI-6000
$21,630

Reputable Company
21 SunPower Panels NE-327 Wht (Not as attractive)
Size 6.86
Production 10,020 annually
Inverter Same
$21,470

Been around about 4 years
30 SolarWorld SW 265 MonoBlack (This would cover just about every square inch of the roof)
Size 7.95 kW
Production is just under 11,000 annually
Enphase M215 Micro-Inverters
$20,200


What you guys think?

Provided all the panels are at the same location orientation, elevation and shading, the annual production from a solar electric system in terms of how much electricity you get per year per nameplate (D.C) Watt of installed capacity should be about the same from one panel to the next. Sunpower MAY be a BIT higher. My non rigorous observation leads me to believe S.P. does less than 5% or so better +/- some per D.C. Watt on an annual basis. S.P. efficiency advantage is mostly, but not entiely a production per area efficiency advantage, not a production per D.C. Watt efficiency advantage. There is a small advantage from increased eff. as temp. goes up, but it's small in the overall scheme of things.

1.) The first S.P. quote looks a little high on annual production (1.8 kW/W per year.). I've got 16 - 327's in north county San Diego with pretty good orientation. I watch it like a hawk. I'll get about 1.7W/kW per year from a new and clean system.

2.) Depending on orientation, elevation and shading, the Solarworld and the other 2 S.P. quotes look a little low on annual production compared to the first S.P.Quote.. ( 1.38 to 1.45 kW/W per year). Other folks in my neighborhood are getting 1.4 to about 1.6 depending on orientation etc. for non S.P. and a bit more than that for S.P. Someone may be trying to sell you more than you may need by underestimating performance. No one ever got fired for selling too much. Caveat Emptor.

3.) Have you considered how much of your annual electric load you want to offset ?

4.) Have you determined the most cost effective amount (%) of your annual load to offset?

5.) The fire marshal may not let you cover an entire roof section with panels. This may knock the Solarworld quote out of the box. Check the fire code yourself and don't assume the they or the vendor give you a correct answer.

[J.P.M.]

[QUOTE=advan24r;93847]

Very well said. I got an updated quote on another Sunpower system (all priced AFTER incentives), but the only downfall is that I would have to seperate the panels into 2 different arrays. Looks like it is slowly dropping after taking more time on shopping around. If I had more room on my roof, I would have tried to make it a larger system to take me off the grid but then again, price is a major factor since I don't want to pay over $18k BEFORE incentives. Are there any other panels that produce this many wattage other than Sunpower though and has the efficiency and quality as them? Also, CSI database..it's been exhausted for PG&E. I know in S.Cal especially San Diego there's still some left over.

8 Sunpower X21 345 Panels @ $3.81/DCWatt
9 Sunpower X21 335 Panels @ $3.78/DCWatt

I'm aware of the rebate exhaustion situation(s). The reason I suggested the CSI database was so you could compare prices and get a reasonable feel for what others in your area have paid for Sunpower and other systems. It's a very valuable tool, full of the type of stuff vendors don't want customers to know. Check it out. Also, if by "take me off the grid" you mean reducing your electric bill to zero, I'd suggest considering that that option, while certainly a choice, may not be the most cost effective one. If you mean taking yourself off the grid by "batteries" - that's probably not an option for most folks anyway it's looked at - at least not at this time.

[Volusiano]

I was told I could not expand with an inline inverter that is why the guy with SolarWorld told me to do the micros?

Normally you want to right size the string inverter so in the future if you want to expand, you'd just add more string inverter that would match with your expansion.

For some reason I thought if you went with Sunpower, you may have only about 20% more room for expansion, in which case it may be OK to "slightly" oversize your current inverter to add on a few more panels to the strings, but not much more. But I looked more carefully and it looks like you have room for 9 more panels before running out of roof space if you go with Sunpower. That would be 9x327W = 2.943 KW which is 40-50% expansion and not just 20%. In that case, Naptown is right, just right size it for now and add on another new (3K?) inverter later if you expand.

On the micros, yes, it may be easier to expand, but like Naptown said, unless they really beef up the wiring up front considerably more for future expansion, you may have to add more wiring to support a lot more panels. Just simple math for when you want to add more power at a fixed voltage, you'll need to add more current -> need to beef up the wiring, unless it's already beefed up for expansion in the first place. That's one of the drawbacks of micros that they normally don't tell you. With strings, you can add more panels to strings to push the voltage (up to around 600V) to add power for the same wiring size with same current. With micros, the voltage is fixed at either 120 or 240V so pushing more power = pushing more current = beefier wiring needed.

To add a new string inverter, you'll need to add new wiring for the new inverter, too, anyway, so it's not any different. Unless you just add a few more panels to existing strings of an existing "slightly" larger inverter like I was thinking earlier.

[J.P.M.]

Also, I asked about the all black. One of the guy says the ALL Black do not perform as well as the White, is that true?

Maybe. Maybe because black surfaces are hotter in the sun than white ones, and hot panels are less efficient than cold ones. BUT, I think the black/white refers to the back (underside) of the panel. I wonder (doubt) if anyone has hard #'s to show for it. Still - the statement seems to smack of common sense.

[KRK]

Wow..Ok, you guys way too smart for me on this board. I guess this is why I came to it, looking for direction.

My annual usage in 2012 was 10,465 and I'm track for 2013 to use 10,950-11,000. I did call a buddy of mine after I read your post, and you are right there are limitations on the coverage and on January 1, 2014 the setbacks are moving to 3 feet from all edges of the roof lines including the roof caps for the City of San Diego and shortly Ca. State wide!!

Do you have the white or all black? Would you be ok with the white on the front of the house?

I have not made any considerations as to the offset. I thought 100% but I'm willing to listen to you experts whom have already done this once?
I have the cash saved up to make the purchase. I just want to make the best financial decision for my family. I have no plans to sell in the next 10 years. It seems an outright purchase is the way to go instead of the pre-pays and the leases and loans?

I just don't know math well enough to figure these things out. I'm a +/- guy. High school grad only!! I carry a gun for a living.....

I don't want to be taken advantage of one way or another.....

Thanks for the help

KRK

[advan24r]

Wow..Ok, you guys way too smart for me on this board. I guess this is why I came to it, looking for direction.

My annual usage in 2012 was 10,465 and I'm track for 2013 to use 10,950-11,000. I did call a buddy of mine after I read your post, and you are right there are limitations on the coverage and on January 1, 2014 the setbacks are moving to 3 feet from all edges of the roof lines including the roof caps for the City of San Diego and shortly Ca. State wide!!

Do you have the white or all black? Would you be ok with the white on the front of the house?

I have not made any considerations as to the offset. I thought 100% but I'm willing to listen to you experts whom have already done this once?
I have the cash saved up to make the purchase. I just want to make the best financial decision for my family. I have no plans to sell in the next 10 years. It seems an outright purchase is the way to go instead of the pre-pays and the leases and loans?

I just don't know math well enough to figure these things out. I'm a +/- guy. High school grad only!! I carry a gun for a living.....

I don't want to be taken advantage of one way or another.....

Thanks for the help

KRK

Hi KRK

not to be mean but would you mind taking your questions to another thread? I've been getting alot of e-mail notifications on this thread since I created it to question about my solar panel set up.

[KRK]

Sure no problem

[advan24r]

Here another quotation from my 3rd bid

10 Sunpower X21 335 @ $3.74/DC Watt
9 Sunpower X21 345 @ $3.69 /DC Watt (unless he was mistaken)

All after incentives. Another question is, is the federal rebate supposed to be calculated BEFORE the Sunpower rebate or AFTER?

[J.P.M.]

Here another quotation from my 3rd bid

10 Sunpower X21 335 @ $3.74/DC Watt
9 Sunpower X21 345 @ $3.69 /DC Watt (unless he was mistaken)

All after incentives. Another question is, is the federal rebate supposed to be calculated BEFORE the Sunpower rebate or AFTER?

1.) Price (~$5.30/Watt) still seems a bit high to me.

2.) I didn't know Sunpower was offering rebates.

[Volusiano]

Another question is, is the federal rebate supposed to be calculated BEFORE the Sunpower rebate or AFTER?

There's already another thread on this forum that discusses how to handle federal tax credit (not rebate) in light of the other rebates (from vendors or utility companies). If you file your federal tax credit with your cost basis BEFORE any rebate (for the highest cost and therefore most federal tax credit), you'll then have to claim all those rebates as taxable income. If your cost basis is AFTER the rebates (lowest cost and therefore least federal tax deduction), then you don't need to claim the rebate as taxable income. Which way to file depends on whether your income tax bracket is more than or less than 30%.

[frizzlefry]

1.) Price (~$5.30/Watt) still seems a bit high to me.

2.) I didn't know Sunpower was offering rebates.

There's a friends and family rebate. Unfortunately I wasn't able to get in on it. Signed contract before a friend who works there told me about it.

[J.P.M.]

There's a friends and family rebate. Unfortunately I wasn't able to get in on it. Signed contract before a friend who works there told me about it.

Some friend.

[joegovette]

1.) Price (~$5.30/Watt) still seems a bit high to me.

2.) I didn't know Sunpower was offering rebates.

Sunpower does offer rebates. I received a $2000 rebate for working at Intel. I am not sure what other companies would qualify for a rebate, but it is something to check into to save a few bucks.

[advan24r]

Even everyone is saying that my quotations are little high, I've already gone through 4 Sunpower Dealer Installers and the prices are all around the same ball park BEFORE incentives. I guess that is just the going rate for the Bay Area.

Anyways, I am that much closer now on signing

I am now leaning between the 2 systems

9 panels of X21 345W (lead time is about 23 weeks out) - Contract Cost $17,377...AFTER incentives (Sunpower KQED rebate + Federal Rebate) $11,356 ($3.66 /DC Watt)

10 panels of X21 335W - Contract Cost $18,671...AFTER incentives $12,412 ($3.705 /DC Watt)

the other quotations were all about $3.80+ /DC Watt after incentives.

Which would you guys choose? Also, which inverter? SunnyBoy or Power One?