Tell me why PV systems are not a scam

[Besoeker]

I said "solar panels produce the most power when they are directly facing the sun (exactly 90 degrees)." If the panels don't produce their maximum output at exactly 90 degrees, then when do they do it? As far as how the power level falls off, a cosine function sounds less drastic than my understanding so you have made me feel a bit better about that.

I think it's actually a sine function. Starts as zero, increases to a maximum as the angle of incidence gets closer to the normal then falls back to zero as the sun sets. Just as the first half of a sinewave behaves.

 

[ggunn]

I think it's actually a sine function. Starts as zero, increases to a maximum as the angle of incidence gets closer to the normal then falls back to zero as the sun sets. Just as the first half of a sinewave behaves.

Most texts approximate it as a cosine function with solar noon as t=0. Same difference, though.

 

[ggunn]

I said "solar panels produce the most power when they are directly facing the sun (exactly 90 degrees)." If the panels don't produce their maximum output at exactly 90 degrees, then when do they do it? As far as how the power level falls off, a cosine function sounds less drastic than my understanding so you have made me feel a bit better about that.

See post #18. The important number isn't the instantaneous power output but the annual energy production.

 

[peterlarsen.suntec]

I would say you are off on your production assumptions. As Ron said, one can use pv watts to get an accurate production figure. They come out very close.

That said I do think there is quite a bit of dishonesty in most payback figures. It seems that most companies:

1. Dont account for the interest / cost of the invested money, and that it could be invested elsewhere

2. Assume the system will be maintenance free.

3. Assume the client will be able to take the full tax credit

Those are probably the big three

Now that being said, how is it different than any other type of thing someone sells? Do you think the car salesman or guy at the cellphone store has your best interests in mind?

I use proposal software with financial modeling that includes.
1. The cost of capital including the customers estimated discount rate.
2. O&M costs of about .05% per year. Inverter replacement in year 14. Most module level electronics are covered under warranty (total replacement) for 25 years. Panels generally carry a 25 year production guarantee.
3. I present my clients with a tax liability calculator and suggest a review of their previous year tax return so they may estimate any credits they may be eligible for. I make it clear that I am not an accountant and that if they want to verify their tax credit eligibility they should let an accountant review the proposal.

The vast majority of solar system owners tell me that their systems exceed performance expectations.

In any case we all know that there are unscrupulous tin men out there. Ultimately, one should educate themselves if they are going to make such an investment. If your salesperson is scratching out numbers on a yellow pad. Beware. If they are using proposal software based on PVWatts the estimates are likely reliable.
Many solar people see the proposal as part of the deliverable. We want to be sure our customers get what they pay for. Happy customers refer new customers. Referrals are the best kind of new customers. They cost far less to acquire than other new customers. It is not only against the best interest of the customer to offer a sketchy proposal but also the salespersons best interest.



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[ggunn]

In any case we all know that there are unscrupulous tin men out there. Ultimately, one should educate themselves if they are going to make such an investment. If your salesperson is scratching out numbers on a yellow pad. Beware. If they are using proposal software based on PVWatts the estimates are likely reliable.

Yes, but PVWatts is only as good as the data you give it. If there is the potential for shading on the roof from trees, nearby buildings, chimneys, heat vents, etc. a shade study must be performed to establish the solar resource available.

 

[peterlarsen.suntec]

https://www.aurorasolar.com/

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[peterlarsen.suntec]

https://www.energyperiscope.com/?page=features

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[jumper]

https://www.aurorasolar.com/

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Peter, please tell us what is in those links. A small description would be great.

 

[infinity]

I like the idea of PV systems but my biggest problem with them is that they are so ugly. As I drive around here and look at the really ugly ones it's my guess the PV panels and shiny EMT run across the roof actually diminish the value of the home. Many of these systems are just an eyesore. If every home had them well then we would have to adapt our thinking to finding beauty in something that is extremely ugly.

 

[jaggedben]

Peter, please tell us what is in those links. A small description would be great.

They are both software services that allow solar sales people to provide comprehensive energy and financial estimates to potential customers, as Peter described in his previous post. There are a few others.

 

[jaggedben]

I like the idea of PV systems but my biggest problem with them is that they are so ugly. As I drive around here and look at the really ugly ones it's my guess the PV panels and shiny EMT run across the roof actually diminish the value of the home. Many of these systems are just an eyesore. If every home had them well then we would have to adapt our thinking to finding beauty in something that is extremely ugly.

Your opinion is not uncommon but is definitely enough of a minority opinion so as not to uniformly affect home prices. I do still find it a bit baffling that people make this argument, and I think it goes away as solar becomes more common in an area. Nobody ever even looks at anybody's roof until people start installing solar panels and then suddenly people care about roofs because now that house looks different.
Nobody ever suggested that asphalt shingles were beautiful before solar panels came along. Nobody complained about skylights or plumbing vents beforehand. There are parts of California's central valley where every house has a tremendously hideous swap cooler on the roof; nobody complains about solar panel appearance in those neighborhoods. In the more affluent neighborhoods where people care the most, they can pay a bit extra for black-on-black panels and interior conduit runs. If it's just shiny EMT that bothers you we can knock that down with some matching spray paint in 5 minutes.

 

[MAC702]

I like the idea of PV systems but my biggest problem with them is that they are so ugly. As I drive around here and look at the really ugly ones it's my guess the PV panels and shiny EMT run across the roof actually diminish the value of the home. Many of these systems are just an eyesore. If every home had them well then we would have to adapt our thinking to finding beauty in something that is extremely ugly.

You must admit they are a lot better looking than the sagging broken hot water lines on the roofs! I always wonder how much money they actually saved before those systems disintegrated in the SW sunshine.

Here, they wrote laws to forbid HOAs from banning solar systems. So you aren't allowed to choose to live in a neighborhood that doesn't allow them.

 

[infinity]

Your opinion is not uncommon but is definitely enough of a minority opinion so as not to uniformly affect home prices. I do still find it a bit baffling that people make this argument, and I think it goes away as solar becomes more common in an area. Nobody ever even looks at anybody's roof until people start installing solar panels and then suddenly people care about roofs because now that house looks different.
Nobody ever suggested that asphalt shingles were beautiful before solar panels came along. Nobody complained about skylights or plumbing vents beforehand. There are parts of California's central valley where every house has a tremendously hideous swap cooler on the roof; nobody complains about solar panel appearance in those neighborhoods. In the more affluent neighborhoods where people care the most, they can pay a bit extra for black-on-black panels and interior conduit runs.

Beauty is in the eye of the beholder. Around here put a swamp cooler on the roof and they might run you out of town. Same for a chain link fence or the 6' high block walls that are common in California.

 

[peterlarsen.suntec]

Peter, please tell us what is in those links. A small description would be great.

Good proposal software that include shade modeling.

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[jumper]

They are both software services that allow solar sales people to provide comprehensive energy and financial estimates to potential customers, as Peter described in his previous post. There are a few others.

Good proposal software that include shade modeling.

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Thank you gentlemen. I appreciate it.

 

[ggunn]

I like the idea of PV systems but my biggest problem with them is that they are so ugly. As I drive around here and look at the really ugly ones it's my guess the PV panels and shiny EMT run across the roof actually diminish the value of the home. Many of these systems are just an eyesore. If every home had them well then we would have to adapt our thinking to finding beauty in something that is extremely ugly.

Ugly is in the eye of the beholder. I make my living in the solar business, so they are beautiful to me. Cue Joe Cocker.

I must admit, though, that some systems are not so beautiful, as when the modules seem to be thrown around on the roof like a giant was dealing cards. But believe it or not, some customers do not care about that; they just want as many modules up there as will fit in any way possible. We try hard to dissuade them when we encounter this; my company's work is on display with every system we install.

 

[jumper]

Ugly is in the eye of the beholder. I make my living in the solar business, so they are beautiful to me. Cue Joe Cocker. .

Don’t tell anyone here, but most normal people think most electrical is ugly, that is if they even notice it.

 

[GoldDigger]

Don’t tell anyone here, but most normal people think most electrical is ugly, that is if they even notice it.

And they definitely do not want to see plumbing.

 

[GeorgeB]

Anybody care to comment on these two assertions? Am I wrong?

I'll give you my take on it, and providing Enphase production graph from a sunny yesterday for comment.

My orientation (tilt) is not optimum for maximizing annual production, perhaps 50 degrees. The array does point almost perfectly south. I'm in upstate South Carolina, about 35 degrees latitude.

It is pretty good for January, however. I'm between 75% and 100% of daily maximum from 10:15 and 3:45. Enphase production suggests I'm getting about 94% of [their] estimated. I have some shading of which they are unaware.

Do I think it is a rip-off? No, I went in with my eyes open. Our local utility (Duke Energy) was pressured by the utilities commission to increase renewable energy. They paid $1.00 per DC Watt. I qualified for a pretty good federal tax rebate but am about 90% retired and didn't qualify for South Carolina's rebate. With some initial fees, Duke pays retail rates for my excess production. From reading the solar energy forums, Duke is far more economical than most others.

I predict, courtesy of rebates and deals created by our guv'mint, payback in 6-7 years. It also let's me pretend to be environmentally conscious. Our kids and grand-kids are fascinated by the system.

I am politically far far right fiscally, and oppose what I was given, but am not unwilling to take a gift that would otherwise go to someone else.

 

[jumper]

And they definitely do not want to see plumbing.

Any pipe. Show a normal people a beautiful conduit/pipe run and the most common response is:

Why can’t you guys hide it in the wall like usual?