Opinion Needed: Which Quote should I go with?

[Vhile1]

Hi all, been trying to do as much research as possible as I prepare to take the plunge of having solar panels installed here in upstate NY. I am at the point where I have 3 options on the table to consider. Some additional information:

1. I plan on getting a battery system for whole home backup purposes in the future, so I need to consider integration and future cost. I accept a sunk cost of $6k as the opportunity cost of a generator.
2. Estimated yearly Electricity usage is 6224-6884 (1st year in new construction) and cost is $.14-.16/watt
3. I value micro-inverters and optimizers as roughly equal. I haven't seen enough proof one way or another.
4. $20k is about my cash out of pocket budget, less is better but not enough to detract from overall cost.
5. I will be able to claim the full tax credits year 1.

Quote 1: Local Solar Installer (LG Chem authorized installer)

$3.45/watt for 15- LG 350 NEON2 panels with optimizers/SolarEdge Inverter+ Monitoring(SE-5000)

Total System Value- $18,113

NYSERDA Rebate - $1,838

Contract Price= $16,275

Fed ITC- $4,231.50/NYS Tax Credit - $4,068.75

Net Cost = $7,974.75 (can save another $500 by not using their bridge loan= $7,474.75)

Available 15 year 0% interest loan for the Net Cost amount

Estimated Production= 5,922kWh/year 1

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Quote 2: NYSSF (Tesla Powerwall authorized installer)

3.35/watt for 16- Sunpower 320w (SPR-E19-320-E-AC w/ Type E(16) and PVS6 Monitoring/InvisiMount

Total System Value- $17,152

NYSERDA Rebate- $1,792

Contract Price= $15,360

Fed ITC- $3,993.60/NYS Tax Credit- $3,840

Net Cost= $7,526.40

Estimated Production= 5,866kWh/year 1

​

Quote 3: Tesla

$2.38/watt for 7.56kw system w/Hanwha panels

Total System Value- $18,000

NYSERDA Rebate- $2,646

Contract Price= $15,354

Fed ITC- $3,992/NYS Tax Credit- $3,839

Net Cost= $7,524

If I add 2 Powerwalls at time of solar installation increases initial cash investment to $29,354 and net cost to $16,722. This makes the 2 Powerwalls w/ installation cost $9,198.

I was told there is a NYSERDA battery storage incentive in the works for upstate NY this year to the tune of $350/kw which would provide a $9,450 incentive on 2 Powerwalls. I am pretty torn between Quote 1 and 2 and I am concerned my decision could have a larger financial impact in the cost of batteries down the road. Any advice? Which system would you choose? Am I right in seeing the first two a similar in value?

Thanks!

[J.P.M.]

Welcome to the neighborhood. Congrads on what looks like through and informed prep.

1.) On the face of it, I'd agree that options 1 & 2 look pretty similar. as you note in #1, any thoughts/concerns about how either one or both offerings would interface w/ current/future battery plans ?

2.) Any shading considerations ? If not, have you considered a string inverter w/out optimizers ? Fewer parts --->>> higher probability of less to go wrong, KISS principle applies.

3.) Snow will impact your array's output depending on snow drift/wind patterns which are probably unknown at this time. What considerations have you made to get at/clean the array ?

4.) Why was the Tesla quote for a system that is so much larger ? Different orientation ? More shading ? ? Annual usage increase plans for the future ?

5.) Are the ouputs modeled by the vendors or by you ? If those are the vendor's modeled outputs, have you done any modeling to verify them ?

With #'s 1 & 2 being close, if they make the cut, I'd respectfully suggest spending as much time evaluating the vendors and their operations as you seem to have spent on all the research/prep./homework you've done so far. Good equipment and a 2d rate installer get you a 2d rate job. A good vendor, and that means a local, licensed electrical contractor who's been around for 10+ yrs. or so and sold solar for at least 5 of those years, with a good reputation and business ethics can help keep you out of trouble and is probably worth a slight premium. You'll sleep better at night when it rains/snows. As the ad says, Priceless !

Whereabouts in Upstate NY ? I'm pretty familiar w/ the area.

[Vhile1]

Capital Region.

1. From what I can gather both IQ7 and SolarEdge are both equally compatible with Powerwall.

2. A little shading from different level roof, plus a lot of different angle and direction for the south facing portions of the roof.

3. I havent thought much about that other than assuming most smaller snowfalls would melt off.

4. Tesla quote is just what is easily available on the website. From what I have read they are not really customizing system sizes to reduce cost and offer a cheaper price.

5. Output was based on vendors quotes. I admittedly havent looked at how to do my own modeling.

Quote 1 is Kasselman Electric and quote 2 is New York State Solar Farm. I feel like NYSSF has been a lot shadier about their sales pitch as they initially provided information using specs from their high end panels that are 22% efficiency, but quoted for the E20's that are 18 or 19%. The overall communication with them hasn't been as enjoyable as the other company.

[Ampster]

Did you say you wanted a generator or were you referring to sunk cost as funds available for Powerwalls?

[Ampster]

I would go with the Tesla proposal because it is so much better price wise. Be prepared for some frustration and go to teslamotorclub forum to get actual user experiences. Any of those proposals should be compatible with future Powerwall installations.

[Vhile1]

Nah, I was referring to the sunk cost of the Powerwalls as I know I wont get an actual ROI on them.

My biggest problem with the Tesla quote is that the CSR i was emailing indicated they are no longer customizing the system sizes. If I overproduce by a lot I am not going to get anything out of it other then energy credits to use in the future. I suppose even at a much worse degradation, 70% of a 7.56kW system may still out produce 90-92% of a 5.2kW system. Hm.

[Ampster]

......
My biggest problem with the Tesla quote is that the CSR i was emailing indicated they are no longer customizing the system sizes. If I overproduce by a lot I am not going to get anything out of it other then energy credits to use in the future. I suppose even at a much worse degradation, 70% of a 7.56kW system may still out produce 90-92% of a 5.2kW system. Hm.

Yes that cookie cutter approach is how they are able to deliver that low price. While others disagree, I think there is an argument for over paneling a system if one beleives there is value in a financial hedge.

I am a Tesla fanboy but don't expect customer support like a local vendor can give you for a PV system. I have had excellent support for my vehicles. A PV system doesn't benefit from the over the air updates that make my vehicle experience great. Powerwall users also get the latest enhancements routinely. You may have read that when a hurricane was about to hit Florida, Tesla made over the air adjustments that allowed Powerwalls to charge up to the max from the grid so they would have the maximum capacity going into that event. They did the same thing prior to scheduled public safety power outages.

[J.P.M.]

Capital Region.

1. From what I can gather both IQ7 and SolarEdge are both equally compatible with Powerwall.

2. A little shading from different level roof, plus a lot of different angle and direction for the south facing portions of the roof.

3. I havent thought much about that other than assuming most smaller snowfalls would melt off.

4. Tesla quote is just what is easily available on the website. From what I have read they are not really customizing system sizes to reduce cost and offer a cheaper price.

5. Output was based on vendors quotes. I admittedly havent looked at how to do my own modeling.

Quote 1 is Kasselman Electric and quote 2 is New York State Solar Farm. I feel like NYSSF has been a lot shadier about their sales pitch as they initially provided information using specs from their high end panels that are 22% efficiency, but quoted for the E20's that are 18 or 19%. The overall communication with them hasn't been as enjoyable as the other company.

Thank you for the response.

If you have not done so already, download a free but dated version of "Solar Power Your Home for Dummies". A revised version is avail. from Am,azon/bookstores for ~ 20 buicks +/- am bit.
Then, download something called PVWatts from NREL. It's a residential solar modeling program. User friendly. fast learning curve. Just read ALL the help screens a few times, avoid GIGO with inputs that are close to site realities, use 10 % system losses and do a few runs. With good inputs, after about an hour or less you'll get a rough feel of what to expect in terms of annual output before any considerations for snow. Once you get familiar, facile and dialed in w/PVWatts do a run for each array orientation and combine the results.

The more information and solar knowledge you get, the higher will be the likelihood of a successful and more fit for purpose installation.

Another common opinion FWIW: Above some basic level of quality, PV panels are and have been a commodity for some time now. LG and Sunpower are close/at top shelf but also probably top price. Good stuff. You want nice, you pay nice. Other, less expensive panels will have about the same (and that means low) probability of failure and same overall quality. If cost effectiveness is one project goal, using the more expensive panels may be leaving some $$ on the table. They may however, have a higher probability of being around longer, especially LG which, as you might surmise, has pretty deep pockets.

I've not seen too many Tesla installations, but if they are anything like the couple dozen SolarCity installs I've monitored in my HOA, I wouldn't want them near, much less on my property. In my direct experience, they're one of the 3 solar bottom feeders. SolarCity was just consistently unprofessional in job execution from the top office on down to the subcontracted labor. Since Tesla Solar seems to be SolarCity rebranded, given their pedigree, I'm skeptical of their current quality. I'd stay with local, established electrical contractors who install PV and expect a higher probability of a more professional result, but that's just me.

The Tesla modularity means it'll be difficult to get close to the most cost effective size according to whatever design parameters you use.

Snow is something installers and peddlers don't seem to want to talk about much. Often you'll hear stuff like "There's no sun in the winter around here anyway so we don't worry about it". While there's a kernal of truth in there, that kernel is small. There is indeed sun in winter in Albany. I lived in Buffalo for 25 years and while there isn't a lot of sun over a 6 month winter there, it still accounted for ~ 25 % of a typical modeled year's output. The capital region's solar potential is similar to that of Buffalo but a bit sunnier in winter, and maybe upping that 25 % to 30 % or so of a typical year's total insolation.

As for accumulation of snow on an array, I'd plan on it and design accordingly. A lot of snow and also ice melt will stick to an array, and a lot of that will stay there for several days between snow events. Count on it. Also don't be surprised if ice dams form on a roof below an array.

On the E20 eff.: You're correct, you won't get 22% eff. out of an E20, the STC eff. will be ~ 20 %, and a system operating eff. averaging something like 17% or so over a year. However, I'd not make too big deal out of it. The STC #'s are area efficiencies. They have some use but beyond some space allocation considerations are more of a marketing tool and distraction than an effective design tool. Pay more attention to operating efficiencies and annual system output. Anecdotally, I've got 16 Sunpower 327's. The STC eff. is listed on the spec sheet as 20.05%. The modeled and actual annual system operating efficiency is ~ 16.9%, that is, of all the solar energy that hits my array over the course of a year, about 16.9% of it gets turned into useful electricity. The actual production #'s are quite close to the modeled #'s. Your results may be similar but a bit different due to different locations.

Point is, STC efficiencies are of limited use. As your first 2 quotes seem to confirm, all 5 STC kW arrays (for example), in the same location, orientation and conditions of service will produce pretty close to the same annual output pretty much regardless of the STC rating of the panels used. Or, put another way, all, 300 W panels for example, will put out 300 W under Standard Test Conditions ("STC"). The more STC efficient but still 300 STC W panels will just have a smaller footprint than the less STC efficient but larger footprint 300 W panel, but both will put out 300 STC W on test and as a practical matter about the same annual output when placed in service. If you are cramped for space, a more area efficient (that is, physically smaller) panel may be necessary to meet array annual production project goals you set. However, the rub there is that more efficient panels (like Sunpower and LG) usually come at a premium price for the panel with the hit coming in the form of higher cost per PV generated kWh and so the design goes back to balancing project goals and priorities such as the system size that balances the mix of PV power and POCO power that results in the lowest NPV cost of supplying electricity to a residence. Read the Dummies book for more info.

I'd get a quote or two for a 5 kW system from local installers using Hanwa or other quality but less top shelf panels just for the hell of it.

[Ampster]

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The Tesla modularity means it'll be difficult to get close to the most cost effective size according to whatever design parameters you use.
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Yes, I agree, But don't let perfect be the enemy of good.
If you compare a Tesla system by derating it to a smaller system that is sized perfectly to the design parameters you use, then you can compare them and if the modular system if less expensive you have gotten as close to a cost effective system as you could get. Also that extra capacity will hedge degradation losses and possibly provide for future growth in energy consumption.

[J.P.M.]

Yes, I agree, But don't let perfect be the enemy of good.
If you compare a Tesla system by derating it to a smaller system that is sized perfectly to the design parameters you use, then you can compare them and if the modular system if less expensive you have gotten as close to a cost effective system as you could get. Also that extra capacity will hedge degradation losses and possibly provide for future growth in energy consumption.

I don't understand what you mean when you write : "If you compare a Tesla system by derating it to a smaller system that is sized perfectly ...". Any way to elaborate ?

[Ampster]

I don't understand what you mean when you write : "If you compare a Tesla system by derating it to a smaller system that is sized perfectly ...". Any way to elaborate ?

I use the term derate to mean, reduce the power rating.
If you compare for example an 7.56 kW Tesla system at $2.38 per Watt or $18.000 dollars to a 5.12 kWh Sunpower system at $3.35 per Watt or $17,152 the obvious choice to me would be the Tesla system.

However if the analysis concluded that you only needed a 5 kW system then some would say the Sunpower system was the perfect system.

I was trying to anticipate the bias about perfect size, which sometimes happens when you ask an Engineer if the glass is half full or half empty and the Engineer says that the glass is too large. That is what I meant by, don't let perfect be the enemy of good.

[Vhile1]

My other issue with the Tesla system is needing to fit 24 panels on my roof without shading. The below is from the Kasselman Solar quote and I can see how 3 mor panels could fit, but beyond that it seems angling or shading issues would come into play.

Also, I forgot to mention that the builder has to approve Street facing solar panels as long as they are still building in the development as outlined in the DCR we signed at closing. They have already approved the below layout, but I am afraid that with Tesla it would be difficult to get a layout available to be approved without me being too far down that rabbit hole.

I plan on doing the modeling today to see what I come up with and I reached out to a few more companies to try and get more quotes.

I did get 2 additional quotes on Energy Sage for companies using Trina and Q-cell panels that both came in at $3.05/watt. Which is only a $1,500 difference and less after incentives.

I am also going to play CSR Roulette with Tesla to see if I can get someone to commit or set me up with a quote for an 18-panel setup.

Thanks for all of the info and helping me with various perspectives.

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[J.P.M.]

I use the term derate to mean, reduce the power rating.
If you compare for example an 7.56 kW Tesla system at $2.38 per Watt or $18.000 dollars to a 5.12 kWh Sunpower system at $3.35 per Watt or $17,152 the obvious choice to me would be the Tesla system.

However if the analysis concluded that you only needed a 5 kW system then some would say the Sunpower system was the perfect system.

I was trying to anticipate the bias about perfect size, which sometimes happens when you ask an Engineer if the glass is half full or half empty and the Engineer says that the glass is too large. That is what I meant by, don't let perfect be the enemy of good.

Thank you for the clarification.

I don't know if you are aware of this or not, but it's not rocket science difficult to figure out that engineering energy systems is not the same as describing how full a container is.

BTW, perfect is not a term I'd use to describe the engineering design process or any component of it, including system sizing. Too absolute. Besides, most all designs can be improved. The professional knows that it's a lot less dichotomous than that. But, I am biased - against not doing the most thorough job as possible to produce the safest, most fit for purpose and most cost effective designs possible within stated project design goals.

For the OP's situation, I'm skeptical of Tesla Solar's price as related by the OP. If it was me, and it sure ain't, while I was at it I'd also check the other 2 prices as well. Seems like maybe ~ $ 3/STC W might be a bit closer to what the market may allow for a decent job. Sunpower and LG are high end and high price for sure, but 40 % higher ? Too much spread. If the Tesla pricing is correct, I'd go to an installer who handled Hanwa and find out what a 5 kW system costs, then tell then, when they say $3.00 or so/STC w, inform them - but don't show them - never volunteer sources in a negotiation - the $2.38/ STC w price and negotiate. You might not get down to $2.38, but you'll wind up with a less oversized system for less $$ than either the S.P. or LG quotes, and you won't need to put up with the Tesla B.S./unprofessionalism.

On your bias toward oversizing: Two things about cost effectiveness as it relates to residential PV:

1.) After safety, and let's talk about the elephant in the room, cost effectiveness, however that's defined by whoever is footing the bill, is many people's biggest and often only reason for getting PV.

2.) One of the biggest and most common killers of cost effectiveness is oversizing of an array. It is however, most likely a necessary evil. that's why I try to be careful about it.

Thinking this over some, It looks to me that we both agree that some system oversizing is necessary and probably unavoidable. I see your method as adding extra size to an array after the design is set> I add size as a considered decision part of the design process. You may (although I certainly don't know for sure) look at it as a "what if" situation and react to some unknown reasons that would make for < 100 % offset as much as possible, or cause a residual electric bill > minimum. using what looks, to me anyway, a scattergun approach. That may work, but IMO, the method has a higher probability of oversizing, and a lower probability of the lowest long term cost of providing electrical service to a residence. It also makes the process economics more vague and fuzzy. The way I do it, I consider future uses and project goals such as an EV or increased family size, or other things like cell degradation, tree growth etc. and plan as best as possible. Taking what amounts to a best guess at where, when and why future loads will occur and their size also aids the process economics drudge.

Your method may get you a lower bill. I believe that's shortsighted. My method will have, all things considered, a higher probability of the best chance for a lower long term cost of providing electric service.

Regardless of method used to decide how much to oversize, one advantage of less oversizing that I haven't seen anyone write about is a result of what happens when something happens like the recent AB 327 mandated changeover from tiered rates to T.O.U. rates for residential customers of the CA, I.O.U. POCOs. Rates got realigned, most customers got or will get shifted to T.O.U. rates, and the T.O.U. times got shifted. One big and bottom line upshot of all that (that was kind of stealthy on the POCO's part actually) was to make the output of an existing PV system on the old T.O.U. rates about 20% to ~ 24% or so less cost effective the instant the new T.O.U. rates, times and tariffs took effect. The hit was even worse for most users who were on tiered rates and got shifted to the new T.O.U. rates. In all cases of existing oversized arrays, an oversized system took a larger % hit with the larger the oversize, the greater the hit. I don't hold out much hope for the CA POCO's letting up the pressure to gut NEM. To the degree that's a correct way to see the situation, it'll only make oversizing an array less cost effective than it already is.

So, oversize - yes- but be very judicious about it.

[Ampster]

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So, oversize - yes- but be very judicious about it.

Yes we agree on that.