Looking at two systems

[Digital21]

Hi,

I've been doing a lot of reading on this forum the past few weeks. The wealth of information is just amazing ... Hope I can add a little to the conversation.

Looking to purchase a system in Long Island, NY and have quotes for two systems:

1 - LG 270 8.5 kW at $3.80 per watt

2 - SunPower E20-245 8.8 kW at $4.05 per watt

The inverter is SunnyBoy for both ... and the installer is a well known local company

We get a utility rebate and State tax credit to go along with the Federal tax credit so the net cost per watt is $1.81 for the LG and $2.01 for the SunPower.

Any thoughts/comments greatly appreciated.

[sensij]

Hi,

I've been doing a lot of reading on this forum the past few weeks. The wealth of information is just amazing ... Hope I can add a little to the conversation.

Looking to purchase a system in Long Island, NY and have quotes for two systems:

1 - LG 270 8.5 kW at $3.80 per watt

2 - SunPower E20-245 8.8 kW at $4.05 per watt

The inverter is SunnyBoy for both ... and the installer is a well known local company

We get a utility rebate and State tax credit to go along with the Federal tax credit so the net cost per watt is $1.81 for the LG and $2.01 for the SunPower.

Any thoughts/comments greatly appreciated.

Only 6.5% premium for Sunpower would be tempting. You won't see it right away, but with a long enough time horizon, the lifetime production numbers should be in Sunpower's favor. The post-rebate 11% difference is a harder sell... how many kwh do you typically consume?

[Digital21]

Only 6.5% premium for Sunpower would be tempting. You won't see it right away, but with a long enough time horizon, the lifetime production numbers should be in Sunpower's favor. The post-rebate 11% difference is a harder sell... how many kwh do you typically consume?

I'm at 13,000kWh and both of these systems are estimated to produce approx. 10,400kWh utilizing the SE and SW parts of the roof.

[sensij]

I'm at 13,000kWh and both of these systems are estimated to produce approx. 10,400kWh utilizing the SE and SW parts of the roof.

Well, it looks like you've got a generous net metering policy, so that helps. Your rates look pretty low though, so even with the rebates, the payback might take some time.

The 8.8 kW Sunpower system looks like 36 panels, but there isn't a whole number of 270's that adds up to 8.5 kW. Was there a reason the two proposals were sized differently?

For systems of similar power rating, and assuming you have the roof space available, there is evidence that suggests the most significant difference between Sunpower and someone else's panels is in the degradation rates. It will take some time for that difference to cancel out the difference in upfront price. Over what time horizon do you plan to benefit from this system?

[silversaver]

If the price is for SP 327+ panel, it will be good. I am not sure the SP 245W panel worth any extra...

[Digital21]

Well, it looks like you've got a generous net metering policy, so that helps. Your rates look pretty low though, so even with the rebates, the payback might take some time.

The 8.8 kW Sunpower system looks like 36 panels, but there isn't a whole number of 270's that adds up to 8.5 kW. Was there a reason the two proposals were sized differently?

For systems of similar power rating, and assuming you have the roof space available, there is evidence that suggests the most significant difference between Sunpower and someone else's panels is in the degradation rates. It will take some time for that difference to cancel out the difference in upfront price. Over what time horizon do you plan to benefit from this system?

For the LG it was more of a quick quote rather than a full workup. So it was an approximation but I was told the cost would be $3.80 per watt.

Yes, the net metering very good ... until it is updated. The rate is at around 17 -18 cents all in, which is borderline for installing a system from a purely cost perspective. Chances are good the rate will increase overtime, the incentives will phaseout and the net metering will be modified. So the decision to install the system now rather than in the future (3 to 5 years) is to catch the incentives, maybe get grandfathered-in for the net metering and help the environment a little. I expect to start benefiting from the system in 6-8 years would really depends on the rate increases.

I am leaning towards the SunPower system. Where does the system cost rank for what I am getting?

[Digital21]

If the price is for SP 327+ panel, it will be good. I am not sure the SP 245W panel worth any extra...

From what I understand, the only difference between the SP 327 and the SP 245 is the name plate watts - the technology behind them is the same. They will have a smaller footprint for the same size system. Please correct me if I am wrong.

[sensij]

From what I understand, the only difference between the SP 327 and the SP 245 is the name plate watts - the technology behind them is the same. They will have a smaller footprint for the same size system. Please correct me if I am wrong.

Correct, the performance warranty is the same, so the degradation curve is still a clear differentiator from other panel manufacturers. "Ranking" your price is fairly location sensitive, so you'd need feedback from other Long Islander's to really know. I sent you a PM with a national installer you might want to contact to find the price floor for your area. FWIW, the LG quote looks a little on the high side for where I live (San Diego), while the Sunpower quote looks more typical or maybe on the low side.

[silversaver]

From what I understand, the only difference between the SP 327 and the SP 245 is the name plate watts - the technology behind them is the same. They will have a smaller footprint for the same size system. Please correct me if I am wrong.

Mostly correct. The newer panels has lower temp coeff lost. The panels tend to produce more energy in higher temp. I would prefer less panels on the roofs because of the weight.

[Digital21]

Mostly correct. The newer panels has lower temp coeff lost. The panels tend to produce more energy in higher temp. I would prefer less panels on the roofs because of the wight.

I think I just hit my limit on the tech curve ... much more to learn. Does the lower temp coeff lost make much of an incremental difference or is it something nice to have since it is available? I am all for cutting edge technology but sometimes the premium charged outweighs the benefit. Also, it means that technology that was perfectly fine yesterday is available at a discount today - which I think may be the case with the quote that I received. The SP 327's are pricing higher.

I agree that less weight on the roof is better.

[Digital21]

Correct, the performance warranty is the same, so the degradation curve is still a clear differentiator from other panel manufacturers. "Ranking" your price is fairly location sensitive, so you'd need feedback from other Long Islander's to really know. I sent you a PM with a national installer you might want to contact to find the price floor for your area. FWIW, the LG quote looks a little on the high side for where I live (San Diego), while the Sunpower quote looks more typical or maybe on the low side.

Thanks for the link ... I was following that thread.

I think the SP quote that I got is slightly better than average for my location. Spoke with a couple of top tier installers and they came in around the same ballpark ... I think they would be marginally more competitive if I indicate I am ready to go ...

Thanks for your help! Just trying to make an informed decision and possibly contribute to the forum in return.

[J.P.M.]

From what I understand, the only difference between the SP 327 and the SP 245 is the name plate watts - the technology behind them is the same. They will have a smaller footprint for the same size system. Please correct me if I am wrong.

I believe they are essentially and for all practical purposes identical in terms of performance. 245 has 72 cells, the 327 has 96. So a nom. 8kW sys. will need 24 327's or 32 245's. The 245's may need a bit more labor, but may be a bit more flexible in terms of layout, although the dimensional difference is mostly in panel width. The weight is almost never an issue - the damn things only weigh ~2.5 #/ft^2, and an 8 kW array or whatever size chosen will weigh the same whether 327's or 245's. Wind is usually a much bigger concern for the Island.

In this case, given your incentives and the relatively small vendor price difference, I might be temped to bite the bullet and Go for the for S.P., unless the LG dealer finds out about the small price diff. Have you checked other LG vendors. That LG price seems kinda high, especially for somewhat dated panels (and, as you note, not a thing wrong with that, just don't pay today's price for yesterday's technology) . Different vendors, different prices, even for same panel. Just a thought.

[Digital21]

I believe they are essentially and for all practical purposes identical in terms of performance. 245 has 72 cells, the 327 has 96. So a nom. 8kW sys. will need 24 327's or 32 245's. The 245's may need a bit more labor, but may be a bit more flexible in terms of layout, although the dimensional difference is mostly in panel width. The weight is almost never an issue - the damn things only weigh ~2.5 #/ft^2, and an 8 kW array or whatever size chosen will weigh the same whether 327's or 245's. Wind is usually a much bigger concern for the Island.

In this case, given your incentives and the relatively small vendor price difference, I might be temped to bite the bullet and Go for the for S.P., unless the LG dealer finds out about the small price diff. Have you checked other LG vendors. That LG price seems kinda high, especially for somewhat dated panels (and, as you note, not a thing wrong with that, just don't pay today's price for yesterday's technology) . Different vendors, different prices, even for same panel. Just a thought.

That is the exact same info that I got for the installer regarding the differences between the two panels - glad to see it confirmed.

I was able to get down to $4.00 per watt on the SP-245 system from the same vendor and while not a huge decrease it is better than the previous quote and shows they are trying to be competitive. So after incentives I am down to $1.95. I don't think they will decrease any further since labor is pretty expensive around here. Also, I don't want to run the risk of the vendor dropping into a different profit tier to get the deal signed and then cut corners on workmanship to make it up. Just want to minimize the amount of money I am leaving on the table but still get a quality product installed. They are going to be installing something that will be used for two decades and although they are providing a 10 year workmanship guarantee I need it to start off in good condition...

[J.P.M.]

That is the exact same info that I got for the installer regarding the differences between the two panels - glad to see it confirmed.

I was able to get down to $4.00 per watt on the SP-245 system from the same vendor and while not a huge decrease it is better than the previous quote and shows they are trying to be competitive. So after incentives I am down to $1.95. I don't think they will decrease any further since labor is pretty expensive around here. Also, I don't want to run the risk of the vendor dropping into a different profit tier to get the deal signed and then cut corners on workmanship to make it up. Just want to minimize the amount of money I am leaving on the table but still get a quality product installed. They are going to be installing something that will be used for two decades and although they are providing a 10 year workmanship guarantee I need it to start off in good condition...

I share most of your sentiment on price, the risk of squeezing vendors too hard and your time horizon. I'd still be watchful for surprises. Again, I do not know your market, but the price diff, S.P. to others seems pretty narrow with that S.P. price lower than just about any other S.P. price I've seen on this forum or elsewhere. Like a politician once said: trust but verify.

[Digital21]

I share most of your sentiment on price, the risk of squeezing vendors too hard and your time horizon. I'd still be watchful for surprises. Again, I do not know your market, but the price diff, S.P. to others seems pretty narrow with that S.P. price lower than just about any other S.P. price I've seen on this forum or elsewhere. Like a politician once said: trust but verify.

I agree the SP-245 price is lower than the SP-327 that I got quoted. I think they have room to move on the LG's but I have not pushed to hard. The reason I was told was because SP is discontinuing the SP-245 and replacing it with either a 255 or 250 ... as such SP is discounting the 245's and they could not give me that pricing on the 327's. The installer has been up-front with me from the start and as far as I can tell not tried to feed me BS but I agree 100% on trust but verify. I will do my part to make sure they keep to their word and not change things towards the end.