Is this solar panel bid reasonable?

Questions on how we spend our money and our time - consumer goods and services, home and vehicle, leisure and recreational activities
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Is this solar panel bid reasonable?

Post by Boston Barry »

I have decided (I think) to purchase solar panels for a home in Colorado (great sun exposure). Want to take advantage of federal investment tax credit before it expires (30% through 2019, then starts decreasing).

I received two bids:
(a) LG 350 W panels, total 7.7kW system. It would produce 8162 kWh per year (28% of home consumption) and is mounted into roof (EDPM roof, membrane would be penetrated). $28000 cost (then -$8000 for Fed Tax Credit) = about $20,000 net cost. Monthly savings about $78.

(b) sunpower panels, total 10.3kW System. It would produce 14139 kWh per year (49% of home consumption) and would be ballasted on roof (no puncture of membrane roof). $39213 cost (then -$12214 for Fed Tax Credit) = about $27000 net cost. Also offered is 18 month interest free loan so first 1.5 years of electricity costs ($2635) saved before paying for system. So effective cost $24.5K or so (and 1.5 years inflation decreasing cost too!) monthly savings about $146.

I much prefer option (b) but have high respect for posters on this forum and would much appreciate anyone with solar panel experience to comment on anything I’m missing / misinterpreting; and whether this makes economic sense to people. Thanks in advance!
Valuethinker
Posts: 49035
Joined: Fri May 11, 2007 11:07 am

Re: Is this solar panel bid reasonable?

Post by Valuethinker »

Boston Barry wrote: Fri Jan 12, 2018 5:22 am I have decided (I think) to purchase solar panels for a home in Colorado (great sun exposure). Want to take advantage of federal investment tax credit before it expires (30% through 2019, then starts decreasing).

I received two bids:
(a) LG 350 W panels, total 7.7kW system. It would produce 8162 kWh per year (28% of home consumption) and is mounted into roof (EDPM roof, membrane would be penetrated). $28000 cost (then -$8000 for Fed Tax Credit) = about $20,000 net cost. Monthly savings about $78.

(b) sunpower panels, total 10.3kW System. It would produce 14139 kWh per year (49% of home consumption) and would be ballasted on roof (no puncture of membrane roof). $39213 cost (then -$12214 for Fed Tax Credit) = about $27000 net cost. Also offered is 18 month interest free loan so first 1.5 years of electricity costs ($2635) saved before paying for system. So effective cost $24.5K or so (and 1.5 years inflation decreasing cost too!) monthly savings about $146.

I much prefer option (b) but have high respect for posters on this forum and would much appreciate anyone with solar panel experience to comment on anything I’m missing / misinterpreting; and whether this makes economic sense to people. Thanks in advance!
I am not US based so can only address certain points:

- do you really use 30k kwhr pa? Is that with electric resistance heating? You might want to look into a heat pump? That's much more than the average US household, even those in high air conditioning zones

- generally have you exploited all opportunities to reduce energy consumption? Leak test & audit by your local utility (you can often get that free). LED lightbulbs. Replacement of pre 2000 fridges (a 1985 fridge can burn c. 2000 kwhr pa, a post 2003 one can burn 550 kwhr - that "beer fridge" in the back is often costing households $15 pcm). Kill-o-watt meters to determine power consumption (instant on features on plasma screen tvs, cable set top boxes, etc.)

- given that you will be generating lots of energy in the day, when you may not need so much, and importing power at night, what is the tariff you are paid for exporting electricity and can the utility change it force majeure? As the number of domestic solar installations grows ("behind the meter" generation), with more and more daytime electricity, this is destabilizing industry economics, and they are going back to the regulators and asking for changes.

- is it worth borrowing money to do this? If you have low yielding investments like bonds, would it be worth selling some of those to do this?
What is the Interest Rate your are being quoted on the loan? What is the term of the loan?

What happens if you sell the house before the loan is paid off?

- besides the tax credit expiring it is likely the US will impose tariffs on Chinese solar panels. As the US does not really manufacture solar panels domestically, that will push prices up (Japanese and Korean manufacturers are likely to take up the slack, but at higher prices)

- generally I would favour B, simply because there is no penetration of the roof membrane

There are probably tables out there of $/ peak kw of capacity installed, give you a feel for comparables.
NightFall
Posts: 336
Joined: Wed Mar 12, 2014 4:38 pm

Re: Is this solar panel bid reasonable?

Post by NightFall »

Option (a) has a payback period of 21 years. Option (b) has a payback period of 14 years assuming all of your numbers/estimates are correct. I would pick (b), especially given that you have a preference for it. However, I might ask how long such systems last. This feels a bit like buying a bond that pays 7% for 20 years but is then worthless. I haven't looked into solar installations very much though.
Bacchus01
Posts: 3182
Joined: Mon Dec 24, 2012 8:35 pm

Re: Is this solar panel bid reasonable?

Post by Bacchus01 »

Battery storage?

Sell back to the grid?

If not one or both, your costs savings will be a fraction of what you’ve posted.

Also, how much of that is labor vs parts? PV is dropping rapidly.
Jeep512
Posts: 121
Joined: Fri Oct 13, 2017 4:34 am

Re: Is this solar panel bid reasonable?

Post by Jeep512 »

Are you doing the solar panels for financial reasons (logic) or just to be environmentally friendly (emotional)?

In one case, it's a simple financial calculation.

In the other case, there's no reason to ask for advice on a financial forum.

How did you do your monthly savings calculation? Did you account for the shorter winter days? Days the panels are covered in snow? Cloudy days? That you will only get peak power during the middle part of the day?

There's a chance that the price of solar may drop 30% over the next 5-10 years. So you may be better off waiting, as it may be cheaper in the future even if there isn't a federal rebate.

For a financial calculation, be sure to include repairs of panels, wiring and the inverter over time. 20 years is a long time, so you need to add in some repair costs.

I just don't see where investing $20k in a home solar system is a wise financial investment. You wait 15 years (best case) for payback, and then after 5-10 more years, the system is worth $0 because it's at the end of its lifetime.

Hopefully, I'm not coming across as too negative. I'm of the general opinion that home solar doesn't make sense for most people. They can be eyesores, as well. If you are remote with frequent power delivery issues, then solar may make more sense. Utility scale solar is really a better solar implementation, so subscribe to your electric providers "green" energy plan if it is available.
4nursebee
Posts: 2664
Joined: Sun Apr 01, 2012 7:56 am
Location: US

Re: Is this solar panel bid reasonable?

Post by 4nursebee »

How much does your electricity cost? Is there a base facilities charge?
What arrangement does your current provider offer to you? This is really part of the equation and must be understood.
How efficient are those panels? Why is there a difference in size of the systems?
What kind of inverter and monitoring is offered?
Are there any businesses that offer solar leasebacks in your area that might improve your ROI?
Why not build a larger system for all of your needs?
ceteris paribus, ROI for 2nd system is better.

We have >10kw system. It supplies 2x what we need, but will never give us a $0 energy bill.
Pale Blue Dot
CnC
Posts: 961
Joined: Thu May 11, 2017 12:41 pm

Re: Is this solar panel bid reasonable?

Post by CnC »

Boston Barry wrote: Fri Jan 12, 2018 5:22 am I have decided (I think) to purchase solar panels for a home in Colorado (great sun exposure). Want to take advantage of federal investment tax credit before it expires (30% through 2019, then starts decreasing).

I received two bids:
(a) LG 350 W panels, total 7.7kW system. It would produce 8162 kWh per year (28% of home consumption) and is mounted into roof (EDPM roof, membrane would be penetrated). $28000 cost (then -$8000 for Fed Tax Credit) = about $20,000 net cost. Monthly savings about $78.

(b) sunpower panels, total 10.3kW System. It would produce 14139 kWh per year (49% of home consumption) and would be ballasted on roof (no puncture of membrane roof). $39213 cost (then -$12214 for Fed Tax Credit) = about $27000 net cost. Also offered is 18 month interest free loan so first 1.5 years of electricity costs ($2635) saved before paying for system. So effective cost $24.5K or so (and 1.5 years inflation decreasing cost too!) monthly savings about $146.

I much prefer option (b) but have high respect for posters on this forum and would much appreciate anyone with solar panel experience to comment on anything I’m missing / misinterpreting; and whether this makes economic sense to people. Thanks in advance!
49% of home consumption... monthly savings about $146.

Did I hear that right? Your monthly electric bill is $300???
Thank you illinois coal cause ours is rarely over $100.


Anyway back on topic, what is the life span of these panels? How will they handle the freeze thaw of Colorado? What are you going to do about the 4± months of snow cover on the panel?
Valuethinker
Posts: 49035
Joined: Fri May 11, 2007 11:07 am

Re: Is this solar panel bid reasonable?

Post by Valuethinker »

NightFall wrote: Fri Jan 12, 2018 6:50 am Option (a) has a payback period of 21 years. Option (b) has a payback period of 14 years assuming all of your numbers/estimates are correct. I would pick (b), especially given that you have a preference for it. However, I might ask how long such systems last. This feels a bit like buying a bond that pays 7% for 20 years but is then worthless.
It's not clear what the residual value of a solar system is, nor whether a buyer for the home will pay that.

Inverters last say 10-12 years. Solar panels last 25 years+ but output falls-- by that time, the panels will probably be replaced with higher performance ones.

So I wouldn't say the system is worthless after 20 years-- it will still generate electricity and that electricity will still have value. However it's not likely to be worth more than OP paid for it and will probably be worth less than that. Then, as now, the future value will be based on a discounted value of the benefits it provides in the future to the owner - so production x avg price (of electricity not therefore bought from the grid & of electricity fed back into the grid)
I haven't looked into solar installations very much though.
So much depends on what you get for the power surplus that you generate (usually around mid day) and feed back into the grid.
Valuethinker
Posts: 49035
Joined: Fri May 11, 2007 11:07 am

Re: Is this solar panel bid reasonable?

Post by Valuethinker »

CnC wrote: Fri Jan 12, 2018 8:10 am
Boston Barry wrote: Fri Jan 12, 2018 5:22 am I have decided (I think) to purchase solar panels for a home in Colorado (great sun exposure). Want to take advantage of federal investment tax credit before it expires (30% through 2019, then starts decreasing).

I received two bids:
(a) LG 350 W panels, total 7.7kW system. It would produce 8162 kWh per year (28% of home consumption) and is mounted into roof (EDPM roof, membrane would be penetrated). $28000 cost (then -$8000 for Fed Tax Credit) = about $20,000 net cost. Monthly savings about $78.

(b) sunpower panels, total 10.3kW System. It would produce 14139 kWh per year (49% of home consumption) and would be ballasted on roof (no puncture of membrane roof). $39213 cost (then -$12214 for Fed Tax Credit) = about $27000 net cost. Also offered is 18 month interest free loan so first 1.5 years of electricity costs ($2635) saved before paying for system. So effective cost $24.5K or so (and 1.5 years inflation decreasing cost too!) monthly savings about $146.

I much prefer option (b) but have high respect for posters on this forum and would much appreciate anyone with solar panel experience to comment on anything I’m missing / misinterpreting; and whether this makes economic sense to people. Thanks in advance!
49% of home consumption... monthly savings about $146.

Did I hear that right? Your monthly electric bill is $300???
Thank you illinois coal cause ours is rarely over $100.
OP is burning at least 2500 kwhr pcm. I am guessing that you pay near the national average of about 11.5 c/ kwhr? Say 10 cents you would be paying $250 per month.

If you heat with gas and basically use electricity for ordinary purposes + AC, you are probably much closer to the US national average of c. 13,000 kwhr p.a. (say 1000-1100 kwhr pcm)?
Anyway back on topic, what is the life span of these panels? How will they handle the freeze thaw of Colorado? What are you going to do about the 4± months of snow cover on the panel?
Panels seem to last 25+ years, but their output declines over time. Inverters last say 10-12 years. Snow cover is a valid point, as is the freeze-thaw cycle (although there have been panels in CO for 40 years, so presumably it has been tackled).
ncbill
Posts: 2053
Joined: Sun Jul 06, 2008 4:03 pm
Location: Western NC

Re: Is this solar panel bid reasonable?

Post by ncbill »

option b: "no roof penetration" through the membrane (flat or low pitch?)
SCV_Lawyer
Posts: 142
Joined: Sun Nov 20, 2016 2:24 pm

Re: Is this solar panel bid reasonable?

Post by SCV_Lawyer »

I don't know prices in CO, but in CA, those quotes would seem high. We just put on 9kW of solar (27 LG panels @ 335W) with microinverters. Total cost was $27,400 before tax credit. And we had a more complicated roof design. We have Spanish "S-tiles." Rather than having the modules installed above the tiles with tile hooks (which looks aesthetically poor in my opinion), we had the S-tiles removed in the area of the solar installation and had a new 30-year composite roof laid down. The modules were installed on the new roof, with the S-tiles reinstalled to the edge of the panels for a flush appearance. Still just $3.04/W before the tax credit.

But the bigger issue I see is that your electricity charges make solar a lot less appealing cost-wise than say, CA. You are paying around 11.5 cents/kWh. We were paying on average on a tiered plan 25 cents. Our system produces 14MWh/year, which is about 100% of our usage, for a savings of $3,500/year. So our pay-off period (ignoring any present value effects) is under 5.5 years (after tax credit). And that ignores the value-add of the solar panels to the house value, which some studies have estimate at $4-$5/W in CA, again, due to the higher energy costs. Since the panels are guarantied to produce no less than 80% of initial value 25 years out, the value add to the house should continue far after the pay-off period.
hightower
Posts: 863
Joined: Mon Dec 12, 2016 1:28 am

Re: Is this solar panel bid reasonable?

Post by hightower »

Boston Barry wrote: Fri Jan 12, 2018 5:22 am I have decided (I think) to purchase solar panels for a home in Colorado (great sun exposure). Want to take advantage of federal investment tax credit before it expires (30% through 2019, then starts decreasing).

I received two bids:
(a) LG 350 W panels, total 7.7kW system. It would produce 8162 kWh per year (28% of home consumption) and is mounted into roof (EDPM roof, membrane would be penetrated). $28000 cost (then -$8000 for Fed Tax Credit) = about $20,000 net cost. Monthly savings about $78.

(b) sunpower panels, total 10.3kW System. It would produce 14139 kWh per year (49% of home consumption) and would be ballasted on roof (no puncture of membrane roof). $39213 cost (then -$12214 for Fed Tax Credit) = about $27000 net cost. Also offered is 18 month interest free loan so first 1.5 years of electricity costs ($2635) saved before paying for system. So effective cost $24.5K or so (and 1.5 years inflation decreasing cost too!) monthly savings about $146.

I much prefer option (b) but have high respect for posters on this forum and would much appreciate anyone with solar panel experience to comment on anything I’m missing / misinterpreting; and whether this makes economic sense to people. Thanks in advance!
We got a quote in the midwest this year for a system that would be around 8.3 kW and total cost after the tax credit was somewhere in the 13k range. So, your quotes seem a bit high to me. Our mounting system would be different since we have a standing seam metal roof and there would be no penetrations (they make a special clamp that clamps the panels to the standing seams). I don't remember what kind of inverters. I do know that our city was doing a special program that somehow got cheaper prices by some how aggregating the purchase of the panels.
hightower
Posts: 863
Joined: Mon Dec 12, 2016 1:28 am

Re: Is this solar panel bid reasonable?

Post by hightower »

Jeep512 wrote: Fri Jan 12, 2018 7:17 am
I just don't see where investing $20k in a home solar system is a wise financial investment. You wait 15 years (best case) for payback, and then after 5-10 more years, the system is worth $0 because it's at the end of its lifetime.
Most well designed solar systems are engineered to break even on costs after about 7-8 years. The solar installer will help you design it to work out that way based on your location, electric usage, weather, etc. SO, we're talking about purchasing a system that will not only pay for itself after 7-8 years, but continue to provide "free" energy for another 15+ years after that. So, it could easily end up working out that a system that operates for 25 years or more, would not only pay for itself long before that, but also provide enough profit to pay for it's replacement when the time comes.

Also, you're not considering the advantage of having some energy independence. Having a way to generate your own electricity, especially coupled with battery storage, means you can function off grid in the event of power outages. With climate change causing more and more unpredictable bad weather lately, this sort of energy independence could become very valuable in years to come.

For me, there is certainly an emotional aspect to solar. I want to do everything I can do to help the environment. But, from a practical/financial standpoint I also believe that owning a solar system and especially coupling it to battery storage, is a very wise move and will continue to become more valuable over time.
4nursebee
Posts: 2664
Joined: Sun Apr 01, 2012 7:56 am
Location: US

Re: Is this solar panel bid reasonable?

Post by 4nursebee »

Off grid with battery makes the payback much longer.
Pale Blue Dot
User avatar
dodecahedron
Posts: 6607
Joined: Tue Nov 12, 2013 11:28 am

Re: Is this solar panel bid reasonable?

Post by dodecahedron »

Is community solar (i.e., buying panels in a "solar farm") an option for you? No roof worries or esthetic issues.

I just bought 20 solar panels in a community solar array rated to deliver 8687 kwhr per year, which is roughly my projected annual usage. The remote rural site is ideal for solar--no trees or hills nearby, huge surrounding empty land, and the angle, direction, and spacing of the array is completely optimized.

I paid $18,632 and will get the 30% federal credit, reducing my net cost to $13,042. There is also a $200/year maintenance fee ($10 per panel), which includes inspection, repairs and maintenance (particularly to inverters), insurance against vandalism and natural disasters, lease payments to the landowner, bookkeeping of the power credits to the 30 or so joint owners, etc. But I don't have to worry about anything on *my* property going forward. It is 25 year arrangement, with option to renew at the end of that time. In the meantime, I have the right to sell or transfer my shares to anyone I want (e.g., future buyer of my home or anyone else of my choosing as long as they live in the large "load zone" served by my electric company) and I can also take the shares with me if I move (as long as I stay within the load zone".)

Edited to add: I get net metering on my electric bill (exactly the same as if the panels were on my roof), so my only ongoing payment to the power company will be the $17/month fixed connection fee. (Had been paying about 12 cents per kwh and utility is requesting a 20% increase in rates.) Utility is pushing back against net metering (for understandable reasons) but this project broke ground in time to be "grandfathered in" to 100% net metering credits. My understanding is that future new projects will gradually get lower net metering credits.
tech_arch
Posts: 253
Joined: Wed May 27, 2015 11:47 am

Re: Is this solar panel bid reasonable?

Post by tech_arch »

hightower wrote: Fri Jan 12, 2018 10:47 am
Also, you're not considering the advantage of having some energy independence. Having a way to generate your own electricity, especially coupled with battery storage, means you can function off grid in the event of power outages. With climate change causing more and more unpredictable bad weather lately, this sort of energy independence could become very valuable in years to come.
This may not be accurate for CO. In FL and PA (and maybe other states), when the grid goes down your panels automatically disconnect as a safety feature, to ensure the grid is not unexpectedly powered when line workers aren't expecting it. If you have a battery, the battery can still function and be actively charged.
SCV_Lawyer
Posts: 142
Joined: Sun Nov 20, 2016 2:24 pm

Re: Is this solar panel bid reasonable?

Post by SCV_Lawyer »

tech_arch wrote: Fri Jan 12, 2018 11:25 am
hightower wrote: Fri Jan 12, 2018 10:47 am
Also, you're not considering the advantage of having some energy independence. Having a way to generate your own electricity, especially coupled with battery storage, means you can function off grid in the event of power outages. With climate change causing more and more unpredictable bad weather lately, this sort of energy independence could become very valuable in years to come.
This may not be accurate for CO. In FL and PA (and maybe other states), when the grid goes down your panels automatically disconnect as a safety feature, to ensure the grid is not unexpectedly powered when line workers aren't expecting it. If you have a battery, the battery can still function and be actively charged.
I believe in all cases and in all states, when the grid goes down, solar without battery back-up will not work, even during a sunny day for the reason you stated, safety of line workers not getting fried by backfed energy. But if you do have battery back-up, there is an automatic transfer switch that cuts the connection to the grid when the grid goes down, so the batteries can run the house (either full or partial through a critical load panel) and recharge from the panels during the day. We are having two Tesla Powerwalls installed, for a total of 28kWh of energy storage. With the SGIP rebates in CA plus the solar credit, it makes these quite affordable for the piece of mind they deliver.
BoilerUp
Posts: 25
Joined: Wed Feb 17, 2010 12:44 pm

Re: Is this solar panel bid reasonable?

Post by BoilerUp »

Have you asked the folks over at www.solarpaneltalk.com?

They'll have a natural internal bias of pro solar in a general should I get solar or not analysis, but if you're looking for sound advice on comparing some quotes, there are some very knowledgeable people on that forum who can help.

Why are the two systems you're comparing significantly different sizes? If you have room on your roof to put up a 10.3KW system in option B, why not add more panels and put up a larger system in option A?
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Re: Is this solar panel bid reasonable?

Post by Boston Barry »

Valuethinker wrote: Fri Jan 12, 2018 6:43 am
Boston Barry wrote: Fri Jan 12, 2018 5:22 am I have decided (I think) to purchase solar panels for a home in Colorado (great sun exposure). Want to take advantage of federal investment tax credit before it expires (30% through 2019, then starts decreasing).

I received two bids:
(a) LG 350 W panels, total 7.7kW system. It would produce 8162 kWh per year (28% of home consumption) and is mounted into roof (EDPM roof, membrane would be penetrated). $28000 cost (then -$8000 for Fed Tax Credit) = about $20,000 net cost. Monthly savings about $78.

(b) sunpower panels, total 10.3kW System. It would produce 14139 kWh per year (49% of home consumption) and would be ballasted on roof (no puncture of membrane roof). $39213 cost (then -$12214 for Fed Tax Credit) = about $27000 net cost. Also offered is 18 month interest free loan so first 1.5 years of electricity costs ($2635) saved before paying for system. So effective cost $24.5K or so (and 1.5 years inflation decreasing cost too!) monthly savings about $146.

I much prefer option (b) but have high respect for posters on this forum and would much appreciate anyone with solar panel experience to comment on anything I’m missing / misinterpreting; and whether this makes economic sense to people. Thanks in advance!
I am not US based so can only address certain points:

- do you really use 30k kwhr pa? Is that with electric resistance heating? You might want to look into a heat pump? That's much more than the average US household, even those in high air conditioning zones

- generally have you exploited all opportunities to reduce energy consumption? Leak test & audit by your local utility (you can often get that free). LED lightbulbs. Replacement of pre 2000 fridges (a 1985 fridge can burn c. 2000 kwhr pa, a post 2003 one can burn 550 kwhr - that "beer fridge" in the back is often costing households $15 pcm). Kill-o-watt meters to determine power consumption (instant on features on plasma screen tvs, cable set top boxes, etc.)

- given that you will be generating lots of energy in the day, when you may not need so much, and importing power at night, what is the tariff you are paid for exporting electricity and can the utility change it force majeure? As the number of domestic solar installations grows ("behind the meter" generation), with more and more daytime electricity, this is destabilizing industry economics, and they are going back to the regulators and asking for changes.

- is it worth borrowing money to do this? If you have low yielding investments like bonds, would it be worth selling some of those to do this?
What is the Interest Rate your are being quoted on the loan? What is the term of the loan?

What happens if you sell the house before the loan is paid off?

- besides the tax credit expiring it is likely the US will impose tariffs on Chinese solar panels. As the US does not really manufacture solar panels domestically, that will push prices up (Japanese and Korean manufacturers are likely to take up the slack, but at higher prices)

- generally I would favour B, simply because there is no penetration of the roof membrane

There are probably tables out there of $/ peak kw of capacity installed, give you a feel for comparables.
To answer these good questions:

Unfortunately yes I use a significant amount of electricity. I have been trying to cut down on consumption with LEDs / low thermostats this past year. Has helped some but lots of windows in house (modern style). Last month 1670 kWh / cost $183.

Xcel policy is net metering: “Xcel Energy's net metering program allows customers to get credit back from excess generation on a bill when the amount of energy a solar panel system generates is greater than the amount of energy consumed from Xcel Energy. Customers receive payment for the excess energy generated.”

Won’t be borrowing anything, plan is to pay entire amount back at 1.5 years — until then, 0%. (After 1.5 yrs loan rate is 1.99%)

Thanks for the insights. Good suggestions regarding leaky house, I will look into consumption side further.
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Re: Is this solar panel bid reasonable?

Post by Boston Barry »

NightFall wrote: Fri Jan 12, 2018 6:50 am Option (a) has a payback period of 21 years. Option (b) has a payback period of 14 years assuming all of your numbers/estimates are correct. I would pick (b), especially given that you have a preference for it. However, I might ask how long such systems last. This feels a bit like buying a bond that pays 7% for 20 years but is then worthless. I haven't looked into solar installations very much though.
Yes lifespan not known for sure, Sunpower SPR-X21-345-AC panels have 25 yr warrantee, degradation lowest in market per salesperson :shock: . It is certainly a bit of a leap of faith
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Re: Is this solar panel bid reasonable?

Post by Boston Barry »

Bacchus01 wrote: Fri Jan 12, 2018 6:55 am Battery storage?

Sell back to the grid?

If not one or both, your costs savings will be a fraction of what you’ve posted.

Also, how much of that is labor vs parts? PV is dropping rapidly.
No battery storage plan, if I have extra Xcel credits me back.? On option (a) labor vs PV panels cost split 50/50. Don’t know for option (b)
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Re: Is this solar panel bid reasonable?

Post by Boston Barry »

Jeep512 wrote: Fri Jan 12, 2018 7:17 am Are you doing the solar panels for financial reasons (logic) or just to be environmentally friendly (emotional)?

In one case, it's a simple financial calculation.

In the other case, there's no reason to ask for advice on a financial forum.

How did you do your monthly savings calculation? Did you account for the shorter winter days? Days the panels are covered in snow? Cloudy days? That you will only get peak power during the middle part of the day?

There's a chance that the price of solar may drop 30% over the next 5-10 years. So you may be better off waiting, as it may be cheaper in the future even if there isn't a federal rebate.

For a financial calculation, be sure to include repairs of panels, wiring and the inverter over time. 20 years is a long time, so you need to add in some repair costs.

I just don't see where investing $20k in a home solar system is a wise financial investment. You wait 15 years (best case) for payback, and then after 5-10 more years, the system is worth $0 because it's at the end of its lifetime.

Hopefully, I'm not coming across as too negative. I'm of the general opinion that home solar doesn't make sense for most people. They can be eyesores, as well. If you are remote with frequent power delivery issues, then solar may make more sense. Utility scale solar is really a better solar implementation, so subscribe to your electric providers "green" energy plan if it is available.
Doing for both financial and environmental reasons. First environmental, but if financial did not make any sense whatsoever then wouldn’t proceed.

Yes winter months accounted for in expected production, I am trusting installer regarding estimated power generation.

Roof is such that panels will be minimally visible or not visible. But yes I too have had doubts regarding the purchase. Appreciate the shared thoughts.
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Re: Is this solar panel bid reasonable?

Post by Boston Barry »

4nursebee wrote: Fri Jan 12, 2018 7:57 am How much does your electricity cost? Is there a base facilities charge?
What arrangement does your current provider offer to you? This is really part of the equation and must be understood.
How efficient are those panels? Why is there a difference in size of the systems?
What kind of inverter and monitoring is offered?
Are there any businesses that offer solar leasebacks in your area that might improve your ROI?
Why not build a larger system for all of your needs?
ceteris paribus, ROI for 2nd system is better.

We have >10kw system. It supplies 2x what we need, but will never give us a $0 energy bill.
Example of electricity cost: 1670kWh —> $183 last month. Not sure of amount of base charge but there is one. Panel efficiency 21.5% I believe in option (b). Not sure why the first bidder made a smaller system, Option b put panels on garage as well. I don’t have room for enough panels to meet all my needs.
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Re: Is this solar panel bid reasonable?

Post by Boston Barry »

CnC wrote: Fri Jan 12, 2018 8:10 am
Boston Barry wrote: Fri Jan 12, 2018 5:22 am I have decided (I think) to purchase solar panels for a home in Colorado (great sun exposure). Want to take advantage of federal investment tax credit before it expires (30% through 2019, then starts decreasing).

I received two bids:
(a) LG 350 W panels, total 7.7kW system. It would produce 8162 kWh per year (28% of home consumption) and is mounted into roof (EDPM roof, membrane would be penetrated). $28000 cost (then -$8000 for Fed Tax Credit) = about $20,000 net cost. Monthly savings about $78.

(b) sunpower panels, total 10.3kW System. It would produce 14139 kWh per year (49% of home consumption) and would be ballasted on roof (no puncture of membrane roof). $39213 cost (then -$12214 for Fed Tax Credit) = about $27000 net cost. Also offered is 18 month interest free loan so first 1.5 years of electricity costs ($2635) saved before paying for system. So effective cost $24.5K or so (and 1.5 years inflation decreasing cost too!) monthly savings about $146.

I much prefer option (b) but have high respect for posters on this forum and would much appreciate anyone with solar panel experience to comment on anything I’m missing / misinterpreting; and whether this makes economic sense to people. Thanks in advance!
49% of home consumption... monthly savings about $146.

Did I hear that right? Your monthly electric bill is $300???
Thank you illinois coal cause ours is rarely over $100.


Anyway back on topic, what is the life span of these panels? How will they handle the freeze thaw of Colorado? What are you going to do about the 4± months of snow cover on the panel?
My vision of Colorado exactly when I lived on East Coast — everyone said, “Moving to Colorado? Better buy a warmer jacket!” But averages 6 Deg warmer than NYC and 300 Days sunshine, there hasn’t been a 24 h period this winter with snow cover on ground. It’s really incredible.

Yes my electric bill is gastly. Big reason why I’m looking into solar. I feel ashamed of house consumption.
User avatar
dodecahedron
Posts: 6607
Joined: Tue Nov 12, 2013 11:28 am

Re: Is this solar panel bid reasonable?

Post by dodecahedron »

Boston Barry wrote: Fri Jan 12, 2018 2:41 pm I don’t have room for enough panels to meet all my needs.
Again, if you don't have physical room for enough panels to meet your needs, I would suggest checking into whether buying shares in community distributed solar could meet your needs. Around here, the cost of buying panels in an offsite remote array seems quite competitive with putting them on your rooftop (and many fewer logistical headaches because there is nobody physically on your property, angles can be optimized, etc.)
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Re: Is this solar panel bid reasonable?

Post by Boston Barry »

SCV_Lawyer wrote: Fri Jan 12, 2018 9:53 am I don't know prices in CO, but in CA, those quotes would seem high. We just put on 9kW of solar (27 LG panels @ 335W) with microinverters. Total cost was $27,400 before tax credit. And we had a more complicated roof design. We have Spanish "S-tiles." Rather than having the modules installed above the tiles with tile hooks (which looks aesthetically poor in my opinion), we had the S-tiles removed in the area of the solar installation and had a new 30-year composite roof laid down. The modules were installed on the new roof, with the S-tiles reinstalled to the edge of the panels for a flush appearance. Still just $3.04/W before the tax credit.

But the bigger issue I see is that your electricity charges make solar a lot less appealing cost-wise than say, CA. You are paying around 11.5 cents/kWh. We were paying on average on a tiered plan 25 cents. Our system produces 14MWh/year, which is about 100% of our usage, for a savings of $3,500/year. So our pay-off period (ignoring any present value effects) is under 5.5 years (after tax credit). And that ignores the value-add of the solar panels to the house value, which some studies have estimate at $4-$5/W in CA, again, due to the higher energy costs. Since the panels are guarantied to produce no less than 80% of initial value 25 years out, the value add to the house should continue far after the pay-off period.
Xcel Energy in Colorado Xcel filed a proposal with the Colorado Public Utilities Commission this month to increase Colorado customer bills by 2 percent annually through 2021 to support the utility’s ongoing developments. So this would be expected rate increase, FWIW, if approved by Commissioner
Topic Author
Boston Barry
Posts: 146
Joined: Sat Jan 14, 2017 3:55 pm

Re: Is this solar panel bid reasonable?

Post by Boston Barry »

BoilerUp wrote: Fri Jan 12, 2018 12:36 pm Have you asked the folks over at www.solarpaneltalk.com?

They'll have a natural internal bias of pro solar in a general should I get solar or not analysis, but if you're looking for sound advice on comparing some quotes, there are some very knowledgeable people on that forum who can help.

Why are the two systems you're comparing significantly different sizes? If you have room on your roof to put up a 10.3KW system in option B, why not add more panels and put up a larger system in option A?
I could ask first bidder to match output, but I just assumed that it would be more expensive, based on cost per kW in their first proposal.

Thanks for the tip of solarpaneltalk. Will check it out!
SCV_Lawyer
Posts: 142
Joined: Sun Nov 20, 2016 2:24 pm

Re: Is this solar panel bid reasonable?

Post by SCV_Lawyer »

Boston Barry wrote: Fri Jan 12, 2018 2:28 pm
To answer these good questions:

Unfortunately yes I use a significant amount of electricity. I have been trying to cut down on consumption with LEDs / low thermostats this past year. Has helped some but lots of windows in house (modern style). Last month 1670 kWh / cost $183.

Xcel policy is net metering: “Xcel Energy's net metering program allows customers to get credit back from excess generation on a bill when the amount of energy a solar panel system generates is greater than the amount of energy consumed from Xcel Energy. Customers receive payment for the excess energy generated.”

Won’t be borrowing anything, plan is to pay entire amount back at 1.5 years — until then, 0%. (After 1.5 yrs loan rate is 1.99%)

Thanks for the insights. Good suggestions regarding leaky house, I will look into consumption side further.
LEDs do make a very big difference. We have about 40 pot lights throughout the house, which were all incandescent and 65W. We replaced them all with LEDs that were 9W and even brighter than the 65W bulbs since there is minimal heat generation. I looked online for daily power usage and average over the prior week was 27kWh and it went down to to 22kWh. Before solar, that saved us $450/year (for a cost of about $200). These have a 25,000 hour life and I think only one has gone out in 2 years. When we decided to go solar, these helped us buy a smaller system and still cover 100% of usage (would have needed 10kW+ system instead of 9kW).

Another savings for people that have swimming pools is to replace a single speed pool pump with a variable rate pump. Our pool pump was 25% of our monthly electricity costs. Because of fluid dynamics, if you run a pump at 1/2 the speed, it actually uses 1/8 of the power. You have to run it twice as long to move the same amount of water, but that still yields a 75% savings in energy.
mervinj7
Posts: 2496
Joined: Thu Mar 27, 2014 3:10 pm

Re: Is this solar panel bid reasonable?

Post by mervinj7 »

SCV_Lawyer wrote: Fri Jan 12, 2018 9:53 am I don't know prices in CO, but in CA, those quotes would seem high. We just put on 9kW of solar (27 LG panels @ 335W) with microinverters. Total cost was $27,400 before tax credit. And we had a more complicated roof design. We have Spanish "S-tiles." Rather than having the modules installed above the tiles with tile hooks (which looks aesthetically poor in my opinion), we had the S-tiles removed in the area of the solar installation and had a new 30-year composite roof laid down. The modules were installed on the new roof, with the S-tiles reinstalled to the edge of the panels for a flush appearance. Still just $3.04/W before the tax credit.

But the bigger issue I see is that your electricity charges make solar a lot less appealing cost-wise than say, CA. You are paying around 11.5 cents/kWh. We were paying on average on a tiered plan 25 cents. Our system produces 14MWh/year, which is about 100% of our usage, for a savings of $3,500/year. So our pay-off period (ignoring any present value effects) is under 5.5 years (after tax credit). And that ignores the value-add of the solar panels to the house value, which some studies have estimate at $4-$5/W in CA, again, due to the higher energy costs. Since the panels are guarantied to produce no less than 80% of initial value 25 years out, the value add to the house should continue far after the pay-off period.
Sounds cool. We were planning on doing something similar in 4-5 years when the roof needs to be replaced. Who did you go with for the panels and installation?
SCV_Lawyer
Posts: 142
Joined: Sun Nov 20, 2016 2:24 pm

Re: Is this solar panel bid reasonable?

Post by SCV_Lawyer »

mervinj7 wrote: Fri Jan 12, 2018 3:22 pm Sounds cool. We were planning on doing something similar in 4-5 years when the roof needs to be replaced. Who did you go with for the panels and installation?
I sent you a PM.
4nursebee
Posts: 2664
Joined: Sun Apr 01, 2012 7:56 am
Location: US

Re: Is this solar panel bid reasonable?

Post by 4nursebee »

I think you should read the fine details on your providers website and make sure you know what the costs will be and which billing methods they offer. Many individuals that I know that have solar were not aware what they were getting into.

Perhaps your utility offers community solar and it might be a better deal? ( I think they do offer it)
Pale Blue Dot
User avatar
unclescrooge
Posts: 6265
Joined: Thu Jun 07, 2012 7:00 pm

Re: Is this solar panel bid reasonable?

Post by unclescrooge »

I just got a 6.5 kw system in Los Angeles. I paid less than $3/w before tax credits.

I would get a few more quotes.

Also, I'm amazed that your 10 kw system will only cover half of your usage.

Either you must have a 10,000 sqft house, or you're growing medicinal herbs! :mrgreen:
madbrain
Posts: 6809
Joined: Thu Jun 09, 2011 5:06 pm
Location: San Jose, California

Re: Is this solar panel bid reasonable?

Post by madbrain »

Both are way too high.

For reference, if you buy just the parts, a 7 kW grid-tie system would cost $11,774 on the site below (I don't have any affiliation) :

https://www.wholesalesolar.com/1891215/ ... att-panels

At $28k with labor, your installer has a huge profit margin.

Ask for separate labor quote, buy parts yourself, and save thousands. You can ask your installer to recommend parts - just purchase directly and not through him to avoid markup. The total including labor should be well under $20k unless there are major things going on in your house (like having to replace main panel, upsize power line from the utility).
madbrain
Posts: 6809
Joined: Thu Jun 09, 2011 5:06 pm
Location: San Jose, California

Re: Is this solar panel bid reasonable?

Post by madbrain »

unclescrooge wrote: Fri Jan 12, 2018 6:42 pm I just got a 6.5 kw system in Los Angeles. I paid less than $3/w before tax credits.

I would get a few more quotes.

Also, I'm amazed that your 10 kw system will only cover half of your usage.

Either you must have a 10,000 sqft house, or you're growing medicinal herbs! :mrgreen:
OP is much farther north, so solar production will be far less.

I have a 9.5 kWh system. Last week, we had a lot of rain in the bay area. Total of only 73 kWh produced for the week ! On my best day ever in the summer (not week) it has produced 65 kWh.
My net consumption from the utility for those 7 days has been 465 kWh. Ie. total of (465 + 73) / 7 = 76 kWh .
We have been driving our 2 electric cars a lot. Probably half of that consumption is for charging. We have natural gas heat for the house.
We did use the outdoor hot tub and indoor sauna quite a bit this last week. The combination of all those factors makes for the perfect storm.
Of course, this is winter. In the summer, production will be much higher (like 4-8x higher). Sauna won't be in use. Hot tub won't use nearly as much energy. Driving electric consumption will be reduced too because of temperature. The electric heater in the cars are a huge factor.
User avatar
prudent
Moderator
Posts: 9085
Joined: Fri May 20, 2011 2:50 pm

Re: Is this solar panel bid reasonable?

Post by prudent »

Topic moved to Personal Consumer Issues.
Angelus359
Posts: 846
Joined: Mon Mar 03, 2014 11:56 pm

Re: Is this solar panel bid reasonable?

Post by Angelus359 »

Ubiquity sells an 8kw system for 12k, without install
2kw can be installed in a half hour (they have a video to prove it)

Do you think 2 hours of time are worth 16000
Systems Engineer
WhyNotUs
Posts: 2610
Joined: Sun Apr 14, 2013 11:38 am

Re: Is this solar panel bid reasonable?

Post by WhyNotUs »

Jeep512 wrote: Fri Jan 12, 2018 7:17 am Are you doing the solar panels for financial reasons (logic) or just to be environmentally friendly (emotional)?

Hopefully, I'm not coming across as too negative. I'm of the general opinion that home solar doesn't make sense for most people. They can be eyesores, as well.
Gee, not sure how someone creating the false choice of either being logical or emotional in this situation could be seen as negative :shock:

As to the OP's original question, the most recent proposal that I have is from 2016 so a little dated. It is $3.52 per watt before any rebates for Suniva panels. Sunpower has premium panels and they are prices with a premium. I also have a Sunpower system and they replaced an inverter after my warranty was up, which I took as a sign of their commitment to quality as they had experienced issues with the inverter and wanted to make it right.
The roof mount system that you using may carry a premium as well. My guess is that the Sunpower bid in in the ballpark.

The fact that the per watt price on your LG system is higher than Sunpower is curious to me. I would have expected the opposite.

Are you an Excel customer? They have a Solar Rewards program that offers additional rebates. I am a consumer in a Rural Coop and they offer rebates as well. We also have a local energy office with small rebates. Your solar company should be willing to pursue those programs and deal with the paperwork.

After all of my rebates and credits, my net cost was less than $2 a watt.
I own the next hot stock- VTSAX
WhyNotUs
Posts: 2610
Joined: Sun Apr 14, 2013 11:38 am

Re: Is this solar panel bid reasonable?

Post by WhyNotUs »

SCV_Lawyer wrote: Fri Jan 12, 2018 9:53 am I don't know prices in CO, but in CA, those quotes would seem high. We just put on 9kW of solar (27 LG panels @ 335W) with microinverters. Total cost was $27,400 before tax credit.
$3 a watt seems about right for LG or similar.
I own the next hot stock- VTSAX
squirm
Posts: 4239
Joined: Sat Mar 19, 2011 11:53 am

Re: Is this solar panel bid reasonable?

Post by squirm »

Somewhat high, try for$2.75 /watt before tax incentives.
hightower
Posts: 863
Joined: Mon Dec 12, 2016 1:28 am

Re: Is this solar panel bid reasonable?

Post by hightower »

SCV_Lawyer wrote: Fri Jan 12, 2018 12:19 pm
tech_arch wrote: Fri Jan 12, 2018 11:25 am
hightower wrote: Fri Jan 12, 2018 10:47 am
Also, you're not considering the advantage of having some energy independence. Having a way to generate your own electricity, especially coupled with battery storage, means you can function off grid in the event of power outages. With climate change causing more and more unpredictable bad weather lately, this sort of energy independence could become very valuable in years to come.
This may not be accurate for CO. In FL and PA (and maybe other states), when the grid goes down your panels automatically disconnect as a safety feature, to ensure the grid is not unexpectedly powered when line workers aren't expecting it. If you have a battery, the battery can still function and be actively charged.
I believe in all cases and in all states, when the grid goes down, solar without battery back-up will not work, even during a sunny day for the reason you stated, safety of line workers not getting fried by backfed energy. But if you do have battery back-up, there is an automatic transfer switch that cuts the connection to the grid when the grid goes down, so the batteries can run the house (either full or partial through a critical load panel) and recharge from the panels during the day. We are having two Tesla Powerwalls installed, for a total of 28kWh of energy storage. With the SGIP rebates in CA plus the solar credit, it makes these quite affordable for the piece of mind they deliver.
Right, when the grid goes down your solar/battery system will start to function as an "off-grid" set up. Which, depending on the size of your system in relation to your electric usage, could maintain your home off grid for as long as needed until the city's power is restored.
240U
Posts: 48
Joined: Wed Nov 22, 2017 5:54 pm
Location: Silicon Valley

Re: Is this solar panel bid reasonable?

Post by 240U »

Having been in the PV industry for a dozen years, owning 30% of an installation company in the South Bay Area and currently a product manager at a company that manufactures inverters for the PV industry I can't believe the misinformation and just plain wrong ideas and concepts being discussed as fact in this thread.

It is rather humorous what people think.
Valuethinker
Posts: 49035
Joined: Fri May 11, 2007 11:07 am

Re: Is this solar panel bid reasonable?

Post by Valuethinker »

240U wrote: Sun Jan 14, 2018 11:37 am Having been in the PV industry for a dozen years, owning 30% of an installation company in the South Bay Area and currently a product manager at a company that manufactures inverters for the PV industry I can't believe the misinformation and just plain wrong ideas and concepts being discussed as fact in this thread.

It is rather humorous what people think.
This is your opportunity to enlighten them, no?
4nursebee
Posts: 2664
Joined: Sun Apr 01, 2012 7:56 am
Location: US

Re: Is this solar panel bid reasonable?

Post by 4nursebee »

240U wrote: Sun Jan 14, 2018 11:37 am Having been in the PV industry for a dozen years, owning 30% of an installation company in the South Bay Area and currently a product manager at a company that manufactures inverters for the PV industry I can't believe the misinformation and just plain wrong ideas and concepts being discussed as fact in this thread.

It is rather humorous what people think.
+1.
Pale Blue Dot
RetiredAL
Posts: 3537
Joined: Tue Jun 06, 2017 12:09 am
Location: SF Bay Area

Re: Is this solar panel bid reasonable?

Post by RetiredAL »

Be aware "net-metering" charging that the solar owners love seems to be heading to to "time-of-day" charging. This is happening because the "net-metering" financial model is not sustainable when solar becomes a significant % of the electric generation. Too many fixed costs someone has to pay for, plus, what you functionally sell to the grid as your surplus during peak daylight is much more costly to the utility than what they can buy/generate power at when you want power from them at a different time.

It would be kinda upsetting for one to to buy solar , then a few years later find that a large part of the anticipated savings went poof.

As said earlier, invest first in energy savings items. Then size it right, as paying for excess KW just to force your bill to near zero, puts you are more risk if you loose "net-metering". I suspect Tesla's bet on a big battery plant has a factor in it expecting battery demand so one can escape a large part of the impact to solar of "time-of-day" charges.

That said, "net-metering" has been a huge factor here in CA for encouraging solar installs, so thus far "net-metering" was remained, though it is being constantly challenged by the utilities. Of course our "inverted" usage charges of 25+cents a KW has also been a factor for pushing to solar. Both of those decisions are political, not cost reality based, thus they functionally drains one's wallet equivalent to a tax. I know, the "tax" word is generally a no-no word in CA, the PC term is "fee".

I say weigh your decision less on finance, more environmental stewardship, but be aware of the pitfalls.
240U
Posts: 48
Joined: Wed Nov 22, 2017 5:54 pm
Location: Silicon Valley

Re: Is this solar panel bid reasonable?

Post by 240U »

It has been posted that perhaps I could enlighten. I have been willing to do that in the past and usually been accused of perpetuating falsehoods.

But I get a kick out of responses like "Buy the components yourself and then hire an installer". Assuming you can find someone to install the system you will pay a lot more for the labor. As an installer my margins are dependent on parts and labor. I cannot forgo a complete sale just to lose margin to install your system. If you find someone to install your system he is probably desperate for any work. Or he is not a good businessman and doesn't understand what he is losing. In addition away from the immediate financial issues, if you install for a person that has proceeded in this way should something should go wrong, infant mortality of the inverter, a bad module diode whatever, it is almost a given that the installer will be called in to "do the warranty work". I got snookered into that exactly once. Never again. You bought the parts you deal with it. I was called in to install not do your overhead.

Installing 1K in 30 minutes. On a comp roof, MAYBE. This was a flat sealed roof. You aren't installing at that rate on your best day. But this advice is given like it is an absolute.

I have had people get a quote and then argue over the proposal that $4K to install a 6K system was robbery. My response was do the labor yourself. After 6 weeks he called and asked if I could "help" with the install. I politely declined. We would have been in and out in a single day.

Making $8K on an 8kW system? That is gross margin. The installer is having to pay for the crew, benefits, insurance, fuel, tools, incidentals and business overhead. He probably has a small office, warehouse, interest payments etc. to cover with that $8K. The margin on the parts cover shipping and logistics in most cases. If you charge much more than that you will not be competitive.

Having said that compared to California this system seems a little expensive and he should get a couple more bids. However, I don't bid in CO. I don't know the permit costs and I don't know the utility requirements. California is far simpler in general to install than other areas of the country. This may be a completely reasonable rate for CO. BTW, cold is GOOD for PV systems. Just make sure you don't put too much PV on the inverter or you may have a problem with clipping in clear cold days. A good installer will always consider this in the design.

These are just a few of the issues I see I could go on. I follow this group as my wife REALLY likes the advice and philosophy of the people here. I follow and for the most part I really like it as well. I am just always hesitant to step in on these kinds of topics.

Note: I understand how all of this comes across. I said it was humorous, I truly find it funny. I am not trying to come down on any one in particular. I am too old and respect the intelligence of the people on this list to do that. It is just funny to me that so much that is "known" by intelligent investors doesn't work in real life.
madbrain
Posts: 6809
Joined: Thu Jun 09, 2011 5:06 pm
Location: San Jose, California

Re: Is this solar panel bid reasonable?

Post by madbrain »

240U wrote: Sun Jan 14, 2018 2:28 pm But I get a kick out of responses like "Buy the components yourself and then hire an installer". Assuming you can find someone to install the system you will pay a lot more for the labor. As an installer my margins are dependent on parts and labor. I cannot forgo a complete sale just to lose margin to install your system. If you find someone to install your system he is probably desperate for any work. Or he is not a good businessman and doesn't understand what he is losing. In addition away from the immediate financial issues, if you install for a person that has proceeded in this way should something should go wrong, infant mortality of the inverter, a bad module diode whatever, it is almost a given that the installer will be called in to "do the warranty work". I got snookered into that exactly once. Never again. You bought the parts you deal with it. I was called in to install not do your overhead.
Buying components myself and hiring the installer is what I did, and it has worked out great so far when I did my solar expansion in 2012. The total for parts and labor was much less than complete bids. And I got to choose the parts I wanted, not what the installer wanted to push on me.

When some parts (micro-inverters) failed on my initial 2010 array, the manufacturer covered the labor to replace them, and paid the installer of my choice - same one who did my expansion. The installer who did the initial array in 2010 was no longer in business and could not do the labor work even though he was paid for parts & labor. So yes, I stand by what I wrote. And I may expand my array yet again in the future and use the same approach. It will cost more than $3/watt this if I do it, because I'll have to move to 400 amp residential service to add more solar.
240U
Posts: 48
Joined: Wed Nov 22, 2017 5:54 pm
Location: Silicon Valley

Re: Is this solar panel bid reasonable?

Post by 240U »

I rest my case. The person that installed your system is no longer in business.

Not a good business plan from my point of view.
240U
Posts: 48
Joined: Wed Nov 22, 2017 5:54 pm
Location: Silicon Valley

Re: Is this solar panel bid reasonable?

Post by 240U »

Sorry, I misread your post. You were fortunate and I am glad it worked for you.

Companies that typically work this way don't stay in business very long.
MathIsMyWayr
Posts: 2775
Joined: Mon Mar 27, 2017 10:47 pm
Location: CA

Re: Is this solar panel bid reasonable?

Post by MathIsMyWayr »

I am cosidering going for rooftop solar, around 4KW capacity. I have a few quotes ranging from around $2.2 to around $3/W after a tax credit of 30%.
  • Are These prices competitive in the Silicon Valley?
    How do you feel going with big guys (Tesla, Sunrun,,,) vs. small ones?
    Any opionions on the type of inverters?
    Should I try to match the current electricy consumption or increase the wattage for future increased usage for more AC or electric cars? I learned that about 6 panels are needed for an electric car with about 1,200 miles/mon.
If you have any recommendation of a specific vendor, I will appreciate.
madbrain
Posts: 6809
Joined: Thu Jun 09, 2011 5:06 pm
Location: San Jose, California

Re: Is this solar panel bid reasonable?

Post by madbrain »

MathIsMyWayr wrote: Sat Apr 21, 2018 10:49 am I am cosidering going for rooftop solar, around 4KW capacity. I have a few quotes ranging from around $2.2 to around $3/W after a tax credit of 30%.
  • Are These prices competitive in the Silicon Valley?
$3 after tax credit is not competitive, IMO.
How do you feel going with big guys (Tesla, Sunrun,,,) vs. small ones?
The big guys have one-size-fits-all formula which may not be the best for your, especially in terms of what equipment they use. This is not necessarily the best for you. If you go with a small guy, you'll have more choice in terms of parts. While the big guys will have lower parts cost because they buy wholesale, the difference goes in their pocket, and not yours. In reality solar systems, will last a long time, except inverters which will need replacements occasionally. I don't personally think it's critical that the original installer still be the one to service in at 10 or 20 years when those times come.

There is no guarantee the big guys won't fail either. Solar city might have had a tough time if not for the sale to Tesla . Sungevity failed - I guess they were not that big, but not small either. My point is, it's not just small installers that can disappear. I'm not sure what benefit I would really get from being with one of the big ones. A solar system is not like a car with thousands of parts where you really need the manufacturer and service personnel to stick around.
Any opionions on the type of inverters?
I'm personally partial to micro-inverters, but those can fail too, and if they do, the install cost may be higher (need to find matching part, and go on the roof). On the other hand, they should last longer than the string inverters. My Enphase D380/M190 and M215 were warrantied for 15 years and 25 years respectively. A few of my D380 failed and were replaced for free by M215s by the manufacturer, who paid for labor as well. Replacement with new model was because no new D380s were available as replacement parts. My M190s have not failed. Enphase is still in business thankfully. I am at year 8 of solar system ownership.
Should I try to match the current electricy consumption or increase the wattage for future increased usage for more AC or electric cars? I learned that about 6 panels are needed for an electric car with about 1,200 miles/mon.[/list]
If you have any recommendation of a specific vendor, I will appreciate.
Electric car usage will not be fixed year round. It is much higher in winter when batteries don't work as well in cold temperatures, and heater uses much more. This accounts for about 30% more electricity usage in winter months. Unfortunately, those are the months with the least solar production as well. Our solar production in peak summer month can up to 3 times the lowest production winter month.

And of course, YMMV goes very much for electric cars too, in terms of what speed you drive, and the terrain.
I would not assume any better than 3 miles/kWh efficiency in winter months, and 4 miles/kWh in summer months.
1200 miles at 3 miles/kWh in winter is 400 kWh. Our 9.4 kW solar system only produced 595 kWh this january for example. A 4kW system would over less than that. You want to make sure you have some excess electricity in summer months when you get money back at peak hour rates, to make up for the huge shortage you will winter months.

Without knowing which size panels, it's impossible to say if 6 panels would cover it. My 9.4 kW system is 40 panels. 6 panels would be 15% of my system or 1.4 kW . This would generate only 88 kWh in lowest winter month, based on 595 kWh production, enough to drive an EV only 265 miles at 3 miles/kWh.

In peak summer month, based on our 1741 kWh produced last July, these same 6 panels would generate 261 kWh, enough to drive 1044 miles at 4 miles/kWh.

Unless you are talking about much bigger panels (300 W+ range), IMO there is no way 6 panels cover your EV consumption for the year. Certainly not in terms of net energy. In terms of bills, possibly, based on time differential between peak and off peak. But that is not likely given the newest PG&E rates. We are granfathered into E-6 rates which is closed to new solar customers. Newer rate schedules have much less favorable hours for solar.

I would say in the current environment, with electricity rates the way they are, and rising for baseline rates, and diminishing for the tiers, you really need to allow for some margin in your system, and oversize it at least little a bit. I would not have said the same 8 years ago when I put my system in. One thing you never want to do is have excess electricity on an annual basis, as you would be giving electricity for free to the utility at that point essentially (net surplus compensation is nothing), so don't overdo it. But plan to cover 100% of the annual energy for your current electricity usage + projected EV consumption, and you will be fine. I highly doubt that a 4 kW system will be enough unless your home uses very little .
Post Reply