Comparing two quotes in central Oklahoma

[Minerva]

First time poster so promise me you will be gentle....

We are considering having a PV Solar system installed at our residence. Our house is about 1600 SF in size and has had additional insulation installed in the attic and thermally efficient windows installed. HVAC is about a 16 SEER with a condensing furnace. Dryer is electric, oven and water heater are natural gas.
The house has no trees around it and a south roof that will allow 13-16 panels, the west roof will take whatever panels the south cannot.I live in central Oklahoma. Our utility provider (OG&E) has a 13.57 monthly demand charge that credits cannot be applied to and will not allow roll over from year to year.

Power consumption for last year:
10.272 KWH consumed.
$1257.54 total cost for power consumed.
$104.80/month average. If we were to go to average billing next year it would be $112.00 as we have a rate increase coming soon.


We have narrowed our search down to two vendors. Both vendors are established and reputable. Both are turn key installations. Vendor 1 is local to Oklahoma and vendor 2 is a Tex/Ok/Kansas operation.

Solar Vendors Comparison:

Vendor 1
For a 93% demand system rated at 5.92 KW installed with a new 200 amp main breaker the cost would be $19,010.00. With a 26% tax credit ($4942.60) factored in the cost would be $14,067.40.


Vendor 2
For a 104% demand system rated at 6.32 KW installed with a new 200 amp main breaker the could would be $23,972.00. With 26% tax credit ($6232.72) factored in the cost would be $17,639.28.


The difference in cost, after tax credit, is $3,571.88.
The cost per watt is 2.38 for Vendor 1 and 2.79 for Vendor 2.


Vendor 1 is quoting Enphase IQ7 micro inverters with Silfab Prime 370 panels, 16 in total.
Vendor 2 is quoting Enphase IQ8M micro inverters with REC Alpha Pure 395 watt, 16 in total.

Both will take care of all permits and licensing requirements.

Vendor 2 has a slightly better labor warranty but I am comfortable with either as far as installation and future service is concerned.

Anyone care to share with me their insights and thoughts?

Thank you.

[J.P.M.]

At a current best case ($14,067/($1,344/yr.)) = ~ 10.4 yr. simple payback, I'd skip the PV and find a better place to put the money and still have it there after 10.4 years.

You are to be congratulated. Seriously. Your's is an example of how conservation measures are alternate energy's most effective competitors. That and low power rates are combining to make PV less cost effective for you than alternate investments.

If more homeowners did the things you have done to your home, there would be less of a need for PV on residential property and more $$ in people's pockets.

[Minerva]

At a current best case ($14,067/($1,344/yr.)) = ~ 10.4 yr. simple payback, I'd skip the PV and find a better place to put the money and still have it there after 10.4 years.

You are to be congratulated. Seriously. Your's is an example of how conservation measures are alternate energy's most effective competitors. That and low power rates are combining to make PV less cost effective for you than alternate investments.

If more homeowners did the things you have done to your home, there would be less of a need for PV on residential property and more $$ in people's pockets.

Thank your for your response, J.P.M.!!

Interesting. Not the response I was expecting from a solar forum but I cannot fault the logic. Of course all vendors made a claim of a quicker ROI but all used a model that included annual increases in billing rates, something not likely to happen. OG&E is currently (May 2022) seeking a rate increase that will increase the average monthly bill by $10.00 and going to a formulation that will allow them to make minor increases without approval from the Oklahoma Corporation Commission. http://OG&E is currently (May 2022) seeking a rate increase that will increase the average monthly bill by $10.00 and going to a formulation that will allow them to make minor increases without approval from the Oklahoma Corporation Commission.

We are still intrigued by the idea and have some further questions.

We were told that the IQ7 will no longer be manufactured, are the IQ8M backwards compatible with the IQ7's?

Does Enphase have a reputation for supporting legacy products? (I worked as an industrial electrician for years, some companies dropped their support for legacy product very quickly, others would support it for several years past the expected life cycle)

What is considered an appropriate ROI timeline?

[slinthicum]

Speaking from the perspective of a San Diego homeowner where our summer peak rate from 4:00p.m. to 9:00p.m. for the EV02 rate is $0.68/kWh, ROI energy costs here certainly justified my decision to install a rooftop solar system, particularly in light of the fact that I have an EV and spa. For you, the answer isn't so clear. Your current rate, based on the information provided is below $0.10/kWh. If that was my rate, even with the EV and spa, I would not have installed the system. I know the temptation when facing increasing rate hikes is to build that potential into the decision process. If I were recommending a pure ROI decision, it might be smart to park $10,000 in a Treasury Direct I Bond (current initial rate is 9.62%) and watch it grow.

[J.P.M.]

Thank your for your response, J.P.M.!!

Interesting. Not the response I was expecting from a solar forum but I cannot fault the logic. Of course all vendors made a claim of a quicker ROI but all used a model that included annual increases in billing rates, something not likely to happen. OG&E is currently (May 2022) seeking a rate increase that will increase the average monthly bill by $10.00 and going to a formulation that will allow them to make minor increases without approval from the Oklahoma Corporation Commission. http://OG&E is currently (May 2022) seeking a rate increase that will increase the average monthly bill by $10.00 and going to a formulation that will allow them to make minor increases without approval from the Oklahoma Corporation Commission.

We are still intrigued by the idea and have some further questions.

We were told that the IQ7 will no longer be manufactured, are the IQ8M backwards compatible with the IQ7's?

Does Enphase have a reputation for supporting legacy products? (I worked as an industrial electrician for years, some companies dropped their support for legacy product very quickly, others would support it for several years past the expected life cycle)

What is considered an appropriate ROI timeline?

Welcome to the neighborhood !

You are most welcome.

Having been around alternate energy and conservation for going on a half century and becoming being one of its biggest fans doesn't mean I'm an apologist for the ignorance and cons often pulled with the purpose of separating the ignorant from their assets.

Conservation and lifestyle adjustments that result in less energy use are almost always more cost effective than generating more energy. As I wrote, you are to be congratulated for those efforts. If you do get PV, know that the system will be smaller (likely less $$) as a result.

As for Enphase being good at product support, seems to me from what I hear from neighbors and this forum - most of which I'd suggest and caution can be more anecdotal and hearsay than verifiably factual - is that their product support is hit/miss. Add to that a lot of what seem to be otherwise reliable mfgs. (LG and Sunpower for example) have pulled out of the panels making business altogether. Also, solar vendors seem to be going out of business more than in the past.

That's not to say that good and reliable vendors aren't around or that PV products are prone to failure. Also, panels from decent mfgs. don't fail much at all. Inverters and ancillary equipment seem to be more troublesome, with a lot of that - but certainly not all of it caused by poor installs by bad vendors.

I can't tell you what an appropriate ROI might be for anyone's situation except mine.
I think these days most folks can do better than the numbers you show if they can tolerate some risk. How much risk ? That's most of why I can't tell you.

But, FWIW, and acceptable ROI for me is any ROI that is greater than the best currently available ROI for any other investment vehicle I might consider after looking at the primary parameters of risk, length of time involved and the impact the choices make on my personal lifestyle. Basically, for me only, it comes down to a life cycle cost analysis. The investment with the most bang for the buck wins. If it's PV, so be it. If not, it isn't the choice. Like Michael Corleone said in "The Godfather": "It's just business".

Then, I look in the mirror for a reality check and say, "well, how important is money against who I think I am, my priorities in life and how I choose to live?".

[foggysail]

You certainly enjoy economical electricity cost!!! However, I recommend that you consider what is happening in our Country pertaining to energy costs that are about soar at places other than at your local gas station! Further, government benefits are beginning to fade into history.

My present cost per kilowatt hour is 11.29 cents plus another almost 15 cents for delivery. I have no clue to what my POCO (Eversource) will increase their delivery charges but for certain.....it will happen and quickly. I have 3 year contract with Constellation and was just notified it is time for renewal at a bargain price of 15.29 for a whopping 35% increase. If I failed to take advantage of this rate before 1 June the rate will be 17.49 or 55% increase and add to the electric cost is the delivery charge!!!!

There was an old commercial on TV that I well remember...........''pay now or pay later'' for a Fram auto engine oil filter. My recommendation is to get solar but do more searching for cost benefits. I contracted here in Massachusetts for a 10.4KW system for under $31K planned for installation in September. The choice is yours and if panel tariffs increase........see the opinion page in yesterday's WSJ

[J.P.M.]

Speaking from the perspective of a San Diego homeowner where our summer peak rate from 4:00p.m. to 9:00p.m. for the EV02 rate is $0.68/kWh, ROI energy costs here certainly justified my decision to install a rooftop solar system, particularly in light of the fact that I have an EV and spa. For you, the answer isn't so clear. Your current rate, based on the information provided is below $0.10/kWh. If that was my rate, even with the EV and spa, I would not have installed the EV. I know the temptation when facing increasing rate hikes is to build that potential into the decision process. If I were recommending a pure ROI decision, it might be smart to park $10,000 in a Treasury Direct I Bond (current initial rate is 9.62%) and watch it grow.

And, if it needs to be said, still have about as much of a certainty as exists anywhere of getting all of that $10,000 back as well.

On those rates, while those on peak summer rates are pretty high - $0.68065/kWh for EV-TOU-2 that you appear to be on, or $0.65158 for those on DR-SES that have a PV system and no EV, one thing that's not immediately obvious but sort of hiding in plain sight is the relatively small number of hours those higher rates are in effect.

Over 365 days, the number of summer on-peak hours is 765 out of 8,760 hours for the year or 765/8,760 = 8.83 %. Granted, most of those are the hours are when peak POCO residential demand occurs, mostly because of A/C loads, but at ~ 9% of all "summer" hours or 5/24~ = 21% of hours over a 153 day "summer" schedule, a fair opportunity seems to exist for time shifting. There's also the idea that the other 5 hourly rates - 3 for winter plus the 2 other summer rates are quite a bit less than the on peak summer rate.

Not that any of SDG & E's rate structures are probably of any practical use to the OP other than to suggest his rates and annual bill are comparatively low, making PV more difficult for him to cost justify.

[Minerva]

Thanks to all that have replied...

[Minerva]

I have two quotes I am considering.

Both are for 16 panels using IQ8 inverters.

One uses Silfab Prime SIL-370 HC panels and comes in at 93% consumption offset with cost of $14,430 after the tax credit is factored in.
The other uses REC 395 Watt Alpha Pure All Black panels and comes in at 103% consumption offset with a cost of $17,740 after tax credit is factored in.
Difference in cost works out to $3,310

I'm comfortable with either company, they have been in business a while and from what reviews I find, do good work.

How do the REC 395 Watt - Alpha Pure - All Black solar panels compare to the Silfab PrimeSIL-370 HC when it comes to performance after 25 years or otherwise?

.

[Ampster]

I would compare the price per Watt and the total generation predicted in kWhs. Is that 10% increased production worth $3000 to you. It depends on your rate for electricity and how that pencils out financially.

[J.P.M.]

I have two quotes I am considering.

Both are for 16 panels using IQ8 inverters.

One uses Silfab Prime SIL-370 HC panels and comes in at 93% consumption offset with cost of $14,430 after the tax credit is factored in.
The other uses REC 395 Watt Alpha Pure All Black panels and comes in at 103% consumption offset with a cost of $17,740 after tax credit is factored in.
Difference in cost works out to $3,310

I'm comfortable with either company, they have been in business a while and from what reviews I find, do good work.

How do the REC 395 Watt - Alpha Pure - All Black solar panels compare to the Silfab PrimeSIL-370 HC when it comes to performance after 25 years or otherwise?

.

Beyond some basic quality in materials and manufacturing, panels are pretty much of a commodity.

I'd spend more time in checking out the vendors.

Because a lot of material that goes into an array is pretty bulletproof, particulary the panels and excepting micros and optimizers which, because they're in/on a hostile (roof) environment that's not easily accessible and so tend to be the most problematic part of the system, the quality of a job most often comes down to the installer and that installer's professionalism and integrity.

Those two qualities will most likely be found in local installers who were already licensed electrical contractors who have been in businees for > 10 years before getting into solar. The big national firms with revolving doors for employees seem to fall short in those two areas of professionalism and integrity.

Just don't fall into the lowest initial price trap. Quality work has a price and a reward. Think long term.

Edit: Reviews are either plants or written by people who, at this point, most likely know less about PV than you do except maybe that their sales person smiled and nodded her/his head up and down a lot. Do your own research on vendors and ask questions you already know the answer to from your read of the Dummies book. You'll not only learn more about PV, but also what the prospective installer doesn't know or tries to B.S. their way out of a situation.

[Minerva]

Beyond some basic quality in materials and manufacturing, panels are pretty much of a commodity.

I'd spend more time in checking out the vendors.

Because a lot of material that goes into an array is pretty bulletproof, particulary the panels and excepting micros and optimizers which, because they're in/on a hostile (roof) environment that's not easily accessible and so tend to be the most problematic part of the system, the quality of a job most often comes down to the installer and that installer's professionalism and integrity.

Those two qualities will most likely be found in local installers who were already licensed electrical contractors who have been in businees for > 10 years before getting into solar. The big national firms with revolving doors for employees seem to fall short in those two areas of professionalism and integrity.

Just don't fall into the lowest initial price trap. Quality work has a price and a reward. Think long term.

Edit: Reviews are either plants or written by people who, at this point, most likely know less about PV than you do except maybe that their sales person smiled and nodded her/his head up and down a lot. Do your own research on vendors and ask questions you already know the answer to from your read of the Dummies book. You'll not only learn more about PV, but also what the prospective installer doesn't know or tries to B.S. their way out of a situation.

The Silfab are warranted to 85.1% at 25 years, the REC at 92% at 25, but am uncertain how much weight to place on that rating.

Your comment about local vs. national is on point. One is a local company where the business owners are both long time residents of this state. One partner owns a construction that has been successful for a number of years and the solar company is an offshoot of it. When talking to the sale rep we mentioned out a roofing company accidentally damaged our HVAC system when installing the roof. The RC took care of the repairs to my system in a quick and professional manner without any real effort on my part. I told the sales guy this impressed me very much, as you really learn about the quality of a company when things don't go to plan. He replied that they had a occasion where one of their guys stepped though the ceiling of a house while doing an install. The owner of the company sent folks from his construction company out and they repaired the ceiling and repainted and cleaned the carpet of the insulation.

The other company is a national one but from the reviews I can find online from various sources seems to do well. Their bid proposal was the most complete and professional looking bid of the ones I have received.

[J.P.M.]

The Silfab are warranted to 85.1% at 25 years, the REC at 92% at 25, but am uncertain how much weight to place on that rating.

Your comment about local vs. national is on point. One is a local company where the business owners are both long time residents of this state. One partner owns a construction that has been successful for a number of years and the solar company is an offshoot of it. When talking to the sale rep we mentioned out a roofing company accidentally damaged our HVAC system when installing the roof. The RC took care of the repairs to my system in a quick and professional manner without any real effort on my part. I told the sales guy this impressed me very much, as you really learn about the quality of a company when things don't go to plan. He replied that they had a occasion where one of their guys stepped though the ceiling of a house while doing an install. The owner of the company sent folks from his construction company out and they repaired the ceiling and repainted and cleaned the carpet of the insulation.

The other company is a national one but from the reviews I can find online from various sources seems to do well. Their bid proposal was the most complete and professional looking bid of the ones I have received.

Understood. Usually, such numbers are subject to interpretation. Back to the idea that most panel manufacturing is pretty much the same which, beyond some basic quality, makes panels a commodity.

Anyway, such claims are effectively impossible to verify in the event of problems putting them in the wild west region of honesty.

With respect to various on line sources, as I wrote, and still my opinion which I believe is based on a bit of common sense and experience is that online reviews and endorsements mean little and can't be trusted for a whole lot that means anything.

Which means you're back to self reliance.

See the work a vendor has done. The rub with that is getting in touch with a vendor's customers. A vendor probably won't provide names of customers in an unbiased way - only the most glowing customers and the most successful projects. It's hard to get unbiased information that way.

In the end, just like most of the rest of life, you're back to your own efforts to get at some version of reality using your brains and what your gut tells you.

[Minerva]

Doing an analysis of the bids, the one that is a 104% consumption offset is cheaper per KWh. They also are using the Enphase IQ8M micro inverters. The selling point of the M series, as I understand it, is that they can go off grid automatically so that if we loose the utility power we can still supply power for the house. In our area we loose power during the winter when ice and trees take out the power lines. Our house is gas/electric so when this happens we would be able to use the solar during daylight hours and I have small gennys I can run the HVAC and fridge/gas stove/freezer off of.

[oregon_phil]

Doing an analysis of the bids, the one that is a 104% consumption offset is cheaper per KWh. They also are using the Enphase IQ8M micro inverters. The selling point of the M series, as I understand it, is that they can go off grid automatically so that if we loose the utility power we can still supply power for the house. In our area we loose power during the winter when ice and trees take out the power lines. Our house is gas/electric so when this happens we would be able to use the solar during daylight hours and I have small gennys I can run the HVAC and fridge/gas stove/freezer off of.

If backup mode is something you really need, read up on the IQM in backup mode: "Design and Installation Parameters for IQ8 Back-up Configurations". Don't make any assumptions about anything. For Enphase IQ8M backup, what equipment is needed, how is it wired, what apps are needed? What happens if the power AND internet goes down? Can I still access my Enphase system in backup mode through phone app using mobile data or local network? How does this affect cost as your original quote #2 only lists new 200amp breaker.

If you don't need back mode, then the Enphase IQ8M potential "Sunlight Backup mode" wouldn't be a selling point in your circumstance.