Is Sunpower price difference worth it? -- thoughts, posting as new topic

[cebury]

Here's the math on those numbers just using my panels. ( not sunpower )
18 280 watt panels producing 25.86 kWh. That's about my average for the last week on sunny days.
Suddenly one panel drops to 75%. So I now have 17 panels producing 1.44 kWh and one panel producing at 75% or 1.08 kWh for a grand total of 25.5 kWh.

Is the math even close to accurate for string inverter systems?

[J.P.M.]

Solar Pete, bcroe, and samotlietuvis,

My point still is that without individual panel monitoring, the Sunpower warranty is virtually useless.

You represent the elite of the elite solar panel owners. You aren't the 1%, you are the .1%. ( congratulations )

How many owners can look at the temp and wind speed and determine what their output should be? ( Solar Pete )
How many owners have identical strings and take DC meter readings? ( bcroe )
How many owners check string Voltage and Current over time. ( samotlietuvis )

How would any of you three know which panel had gone bad?

Would you call your installer and say, well my production has dropped from 25.86 kWh to 25.50 kWh, could you come out and check all my Sunpower panels?
What would you say after the laughter on the other end of the phone call ended.

Here's the math on those numbers just using my panels. ( not sunpower )
18 280 watt panels producing 25.86 kWh. That's about my average for the last week on sunny days.
Suddenly one panel drops to 75%. So I now have 17 panels producing 1.44 kWh and one panel producing at 75% or 1.08 kWh for a grand total of 25.5 kWh.

I'm not pimping micro inverters or Solar Edge, just saying without one of those 2 systems its, VERY, VERY, VERY unlikely most people
that own Sunpower systems could or would EVER detect a single panel failure.

I don't think anyone is disagreeing with the idea of the difficulty of monitoring individual panel output. Similarly, most folks who have vehicles powered by multicylinder ICE's will probably have trouble monitoring individual cylinders. More to the point, most don't care. An 8 cylinder Camaro costs less than an 8 cylinder Mercedes roadster. The Mercedes warranty is a bit better. Most owners probably don't monitor each cylinder, but probably notice a performance drop off if the vehicle's performance is important to them.

Same goes for solar array performance. Some folks care. Some not so much. Some, none at all.

Enough already. The S.P. warranty, like most solar warranties, is a marketing tool. Leave it at that.

[sensij]

Suddenly one panel drops to 75%. So I now have 17 panels producing 1.44 kWh and one panel producing at 75% or 1.08 kWh for a grand total of 25.5 kWh.

Your definition of "failure" is much too narrow. How often does a single panel drop 25%? Most of the common failure modes, which are already rare, would drop the panel voltage by at least 33%, which is relatively detectable because it isn't very sensitive to irradiance. Yes, any failure mode that affects *only* current output would be harder to detect, but can you even propose how that could happen? The monitoring on string inverters is sufficient to detect most of the known types of failure, especially with two similar arrays to compare.

[Yaryman]

Enough already. The S.P. warranty, like most solar warranties, is a marketing tool. Leave it at that.

You are correct, it's a marketing tool the really means nothing, but people pay up for it.

[J.P.M.]

You are correct, it's a marketing tool the really means nothing, but people pay up for it.

Well, some people do. (A few) Others know better.

[KingAntonio]

I had this question when i started doing my research and going by everything i read the short answer is NO. I'm installing RenoSolar in a few days. Good luck

[Guest]

Really, if given a reasonable estimate for sunpower, which for a 3kW-5kW system is around $4.40-4.60 per watt and $4.10-$4.30/watt for 6kW-9kW and $3.90-$4.10 for 10kW+ systems, the price difference IS worth it. You will get 75% more energy over the lifetime of the panels. 8% more per rated watt, the degradation rate for Sunpower is actually only 33% of or 3 times better than the LG panels. You'll use, in your case, 1 less panel. I'd take a hard look at the extended production guarantee on the LG proposal before you go forward with it. If you need any more info I'd be glad to help.

[solar pete]

Really, if given a reasonable estimate for sunpower, which for a 3kW-5kW system is around $4.40-4.60 per watt and $4.10-$4.30/watt for 6kW-9kW and $3.90-$4.10 for 10kW+ systems, the price difference IS worth it. You will get 75% more energy over the lifetime of the panels. 8% more per rated watt, the degradation rate for Sunpower is actually only 33% of or 3 times better than the LG panels. You'll use, in your case, 1 less panel. I'd take a hard look at the extended production guarantee on the LG proposal before you go forward with it. If you need any more info I'd be glad to help.

Hi Advice4SoCal it is not cool for newbies to come here seeking free advertising or self promotion, and trying to justify Sunpowers sales hype BS is not going to go down to well either, cheers.

[sunnyguy]

Really, if given a reasonable estimate for sunpower, which for a 3kW-5kW system is around $4.40-4.60 per watt and $4.10-$4.30/watt for 6kW-9kW and $3.90-$4.10 for 10kW+ systems, the price difference IS worth it. You will get 75% more energy over the lifetime of the panels. 8% more per rated watt, the degradation rate for Sunpower is actually only 33% of or 3 times better than the LG panels. You'll use, in your case, 1 less panel. I'd take a hard look at the extended production guarantee on the LG proposal before you go forward with it. If you need any more info I'd be glad to help.

Ooooh. Ahhhhh. What other dancing monkey tricks do you have for us?

[ButchDeal]

Really, if given a reasonable estimate for sunpower, which for a 3kW-5kW system is around $4.40-4.60 per watt and $4.10-$4.30/watt for 6kW-9kW and $3.90-$4.10 for 10kW+ systems, the price difference IS worth it. You will get 75% more energy over the lifetime of the panels. 8% more per rated watt, the degradation rate for Sunpower is actually only 33% of or 3 times better than the LG panels. You'll use, in your case, 1 less panel. I'd take a hard look at the extended production guarantee on the LG proposal before you go forward with it. If you need any more info I'd be glad to help.

what a pile of crap. 75% more over the lifetime, You got some proof on that one!? Take you BS crap someplace else.

[inetdog]

what a pile of crap. 75% more over the lifetime, You got some proof on that one!? Take you BS crap someplace else.

You mean 7% more per year over ten years does not equal 70%?

[Guest]

LOL

Really 75% is conservative.

Guaranteed degradation for a Lease is .25% LG average degredation (http://www.lg.com/us/commercial/sola...lg-LG360N2W-B3) is .6%= .35% difference
8% more energy per rated watt (SP rates their panels at 8% less than their actual production)
No light induced degredation = 2% more from day one

All added up: .35%+2%+8%=10.35%

10.35% * 20 years for the typical SunPower Lease= 207% more for the same size system if you really want to get serious about it. But that is so incredible why say it to begin with when people dont even believe 75%.

http://www.solarreviews.com/manufacturers/sunpower/

http://www.solarreviews.com/installers/sea-bright-solar-reviews/

Admin note, I got changed a couple of urls, is this an example of the caliber of the solar sales reps? Seems to have fallen for the marketing guff

[inetdog]

LOL

Really 75% is conservative.

Guaranteed degradation for a Lease is .25% LG average degredation (http://www.lg.com/us/commercial/sola...lg-LG360N2W-B3) is .6%= .35% difference
8% more energy per rated watt (SP rates their panels at 8% less than their actual production)
No light induced degredation = 2% more from day one

All added up: .35%+2%+8%=10.35%

10.35% * 20 years for the typical SunPower Lease= 207% more for the same size system if you really want to get serious about it. But that is so incredible why say it to begin with when people dont even believe 75%.

https://www.sunpower.com/home-solar

https://www.seabrightsolar.com

https://www.socalfreesolarestimate.com

You are actually doing it! And I was just trying to make a joke.

You are saying that from day one the SP panels produce 8% more power than another panel of the same rating.
That means that over the 20 year lifetime the SP panel producs 8% more power than the other panel. Multiplying the 8% by 20 tells you that over the course of 20 years the excess is 160% of ONE YEAR'S production, not that the total 20 year production is 160% greater.
Now when you look at the degradation, that will be 20 times as great at the end of 20 years (which means that the average degradation seen over the 20 year period will be ten times the single year figure, by the way.)
Your numbers do not mean what you think they mean and therefore do not make any sense.

[sunnyguy]

10.35% * 20 years for the typical SunPower Lease= 207%

inetdog called it and you still fell for it. That is not how math works.

i guess we know how these leasing companies are getting people to sign for sunpower systems now.

[ButchDeal]

LOL

Really 75% is conservative.

Guaranteed degradation for a Lease is .25% LG average degredation (http://www.lg.com/us/commercial/sola...lg-LG360N2W-B3) is .6%= .35% difference
8% more energy per rated watt (SP rates their panels at 8% less than their actual production)
No light induced degredation = 2% more from day one

All added up: .35%+2%+8%=10.35%

10.35% * 20 years for the typical SunPower Lease= 207% more for the same size system if you really want to get serious about it. But that is so incredible why say it to begin with when people dont even believe 75%.

Soooo you are in sales I guess. Well that isn't how math works there guy. Go sell your yellow primer someplace else.