Quotes are in...survey says?

[Gstachura]

EDIT...added Quote 4 and listed the companies w/ links

My initial post on the intro page was that I was beginning the process of obtaining quotes for my Corona CA home (18° concrete tile roof). I've met with 6 different companies, obtained 10 different quotes of various panel/inverter brands, and have narrowed it down to three based on a number of criteria. Some were ruled out immediately as I knew more than their sales rep did and they were supposedly the professionals (I've only been researching for a month now). So here's the scoop, please let me know your opinions on what's been proposed.

Quote 1 - Jamar Power Systems http://www.solarreviews.com/installe...stems-reviews/
System size - 9.6 kW
Panel - 32, LG 300N1C-B3 Black, 300 watt
Inverter - 1, SolarEdge SE7600 w/ 32 SolarEdge P300 Optimizers
Racking - Unirac or Iron Ridge
Warranty - 10 yrs installation, 25 yrs on panel output
Cash price before tax credit - $29,775
Price per watt - $3.10
Estimated annual production - 13,175 kWh per year
Pros - lowest price per watt, LG panels rated very high, excellent contractor reviews
Cons - warranty not as good as quote 2,

Quote 2 - PetersenDean http://www.solarreviews.com/installe...nergy-reviews/
System size - 9.52 kW
Panel - 34, SolarWorld Sun Module Plus SW280 Black, 280 watt
Inverter - SMA Sunny Boy (model not specified)
Racking - Not specified
Warranty - 30 yrs. installation, 30 yrs. kWh production, 25 yrs. on panel output
Cash price before tax credit - $35,098 Lowered to $33,250
Price per watt - $3.69 now $3.49
Estimated annual production - 13,033 kWh per year
Pros - best warranty, all USA made equipment, excellent contractor reviews
Cons - higher price per watt

Quote 3 - Triple Line Solar http://www.solarreviews.com/installe...solar-reviews/
System size - 8.1 kW Upsized to 9.6 kW
Panel - 32, LG 300N1C-A3 Black, 300 watt
Inverter - 2, SMA Sunny Boy SB000TL-US-22
Racking - Quick Mount
Warranty - 10 years on installation, manufacturer's on equipment
Cash price before tax credit - $32,750
Price per watt - $3.82 now $3.41
Estimated annual production - 12,082 kWh per year
Pros - LG panels rated very high, excellent contractor reviews
Cons - highest price per watt

Quote 4 - LA Solar Group http://www.solarreviews.com/installe...group-reviews/
System size - 9.6 kW
Panel - 32, LG 300N1C-B3 Black, 300 watt
Inverter - 1, SolarEdge SE7600 w/ 32 SolarEdge P300 Optimizers
Racking - Iron Ridge
Warranty - 20 yrs labor/installation, manufacturers warranty on equipment
Cash price before tax credit - $29,088
Price per watt - $3.03
Estimated annual production - 14,120 kWh per year
Pros - lowest price per watt, LG panels rated very high, excellent contractor reviews
Cons - Only been in business for 3 years

So there you have it. Thoughts??? Thanks in advance!

[sensij]

What is your estimated annual energy consumption?

Also, where are the kWh estimates coming from?

[solarix]

The problem with the 2nd two quotes using two inverters is that the combined output current is going to be more than code allows for backfeeding a 200A service. SMA makes a 7700W version which solves this problem but a 9.5kW array like the 2nd quote may be a little overpowering. Quote 3 using a single SB7700TL inverter should even be significantly cheaper.

[Gstachura]

What is your estimated annual energy consumption?

Also, where are the kWh estimates coming from?

My last 12 month average was 14,777 kWh. Annual production estimates are from the solar companies.

[sensij]

My last 12 month average was 14,777 kWh. Annual production estimates are from the solar companies.

Your kWh estimates look low. Find out what azimuth and tilt your array will be, and check out PVWatts to generate your own estimate. Use premium panels, roof mount, 8-10% loss if the array will not regularly see shade. Read the documentation to understand what PVWatts is doing.

You might be able to push for a smaller system at the $3.30-$3.50 / W price point . Take some time to understand how you are billed by your power company, and you might find that offsetting 100% or more is not as cost effective as offsetting some portion less than that.

[Gstachura]

Thanks for the info sensij. My roof pitch is 4:12 or 18° all the way around, with 16 panels on the 270° azimuth, 6 on the 180° and 10 on the 90° and very limited shading if any at all. In reviewing the quote again, the production estimate is from PV Watts but I'll run the numbers myself too.

[Gstachura]

So I ran the numbers on PV Watts. Unfortunately, PV watts does not let you choose multiple azimuths as my lay out would be (16 panels on the 270° azimuth, 6 on the 180° and 10 on the 90°). That being said, I ran a scenario for each azimuth and came up the following.

270° - 13,864 kWh per year
180° - 15,454 kWh per year
90° - 13,407 kWh per year

Average of all three, 14,241 kWh per year.

I'm not sure if this is a good way to estimate production values but it does appear that the quote provided may be underestimated. But, is this done so that when the actual come in the company can say the system is exceeding expectations?

[thejq]

So I ran the numbers on PV Watts. Unfortunately, PV watts does not let you choose multiple azimuths as my lay out would be (16 panels on the 270* azimuth, 6 on the 180* and 10 on the 90*). That being said, I ran a scenario for each azimuth and came up the following.

270* - 13,864 kWh per year
180* - 15,454 kWh per year
90* - 13,407 kWh per year

Average of all three, 14,241 kWh per year.

I'm not sure if this is a good way to estimate production values but it does appear that the quote provided may be underestimated. But, is this done so that when the actual come in the company can say the system is exceeding expectations?

You can take the pvwatt outputs divide by the number of panels for each az to get per panel output. Then multiple the panels for each az and sum to get the total. Also when running pvwatt, use 6% or 8% system loss (instead of the 14% default) to get a more accurate estimate. What did you use as tilt for your flat roof?

[Gstachura]

Then multiple the panels for each az and sum to get the total. What did you use as tilt for your flat roof?

Sorry but I'm not following this part of the equation. 4:12 pitch = 18° tilt.

[thejq]

Sorry I meant to say, multiply the per panel output by the number of panels in each az and then sum to get the total output. Also when you said flat concrete roof, I thought, flat as in level (or zero degrees). Apparently you meant the tile itself is flat, and roof is tilted already. So never mind with the 2nd part of the question.

[Gstachura]

I reran the numbers on PV Watts as suggested by thejq for each azimuth and came up with a total of 14,375 kWh per year versus the estimated annual production of quote 1 at 13,812. Not too far off and I suspect they used the PV Watts default settings rather than some of the adjustments I made for inverter efficiency, shading, etc. I also tend to think as mentioned before that they underestimate so when the system produces more they can show that as good marketing on how well the system they are selling performs.

With all that out of the way, does anyone have any thoughts on the quotes and systems themselves, pricing, etc. or am I missing anything? $3.28 per watt seems like a great deal from what I've been reading on this forum and the LG panels appear to rank very high performance-wise from what I've read.

[solar pete]

I reran the numbers on PV Watts as suggested by thejq for each azimuth and came up with a total of 14,375 kWh per year versus the estimated annual production of quote 1 at 13,812. Not too far off and I suspect they used the PV Watts default settings rather than some of the adjustments I made for inverter efficiency, shading, etc. I also tend to think as mentioned before that they underestimate so when the system produces more they can show that as good marketing on how well the system they are selling performs.

With all that out of the way, does anyone have any thoughts on the quotes and systems themselves, pricing, etc. or am I missing anything? $3.28 per watt seems like a great deal from what I've been reading on this forum and the LG panels appear to rank very high performance-wise from what I've read.

Sounds like you have done well from your time here and all your research, anything below $3.50 per watt seems like a good deal, cheers.

[thejq]

I reran the numbers on PV Watts as suggested by thejq for each azimuth and came up with a total of 14,375 kWh per year versus the estimated annual production of quote 1 at 13,812. Not too far off and I suspect they used the PV Watts default settings rather than some of the adjustments I made for inverter efficiency, shading, etc. I also tend to think as mentioned before that they underestimate so when the system produces more they can show that as good marketing on how well the system they are selling performs.

With all that out of the way, does anyone have any thoughts on the quotes and systems themselves, pricing, etc. or am I missing anything? $3.28 per watt seems like a great deal from what I've been reading on this forum and the LG panels appear to rank very high performance-wise from what I've read.

Looks like you're going for 100% sizing. If you don't expect to increase your consumption in the future, you are probably going to leave $$$ on the table at true up time. FYI, all CA utilities charges minimum usage fees between $5-10/month right now. So if you average net consumption is less than that, you pay the minimum. If you're going for 100% sizing, you should at least subtract the minimum usage from the top line. If you can utilize some type of TOU to maximize production revenue by shifting your usage around, your sizing could be even less. Don't just look at the $/Watt price, proper sizing is more important (given a consumption level) for saving your money.

[Gstachura]

Hmmm...I'm not necessarily looking to offset SCE by 100% for that very reason. Per the company quoting, that was also a reason to keep it a little under sized. If anything, my consumption may drop as I change out lighting to LED and replace my pool pump with a variable speed pump and I have no plans for an electric car at this time unless CA gas prices get stupidly high again.

[Tycron]

I'm also doing my research on going solar. I'm in southern Ca and I haven't been getting near the price you are being offered. Can you PM the companies you got the quotes from? Thanks in advance.