Newbie Here - Purchase advice

[namelama]

Hello Everyone! I'm in the middle of getting quotes for a home solar system and live in So. Cal. Our home does not have any shading issues and the home faces south. I have two large west facing and one large southern facing portions of the roof where it has been suggested to install the panels. The south facing portion of the roof is the front of our home and would rather not install panels on the south portion even though it is the most ideal location. I use approximately 6400 Kw annually ($130-230/mo) but we're close to retirement and we'll probably use a little bit more electricity since we'll be home. Here are the quotes which I've received:

Independent contractor (which I've used before) offered $2.90/watt 320w LG Blk panels w/Enphase IQ6 micro inverters
20 panels (one line straight across the south portion) $18,300 / 6400Kw
22 panels (on both west facing portions) $19,800 7000Kw
23 panels (on both west facing portions) $21,000 7400Kw

Independent contractor offered $3.17/watt 290w Solar World panels w/Enphase IQ6 mircroinverters

22 panels (on the south portion) $17,864 / 6400Kw

Sunpower offered 5Kw system $3.51/watt 327w Sunpower panel with Micro inverters $19,587

We like clean black panels with no visible grid but not all vendors have that available without a large price increase. Warranties are all approximately the same except Sunpower is 25yr on everything (production, replacement) except monitoring or shipping/labor is 10 & 12 years respectively. I have the following questions:

Should I be pricing $ per/watt?
How important is the panel considering the warranties are relatively the same and just considering whether the company will be around for years to come?
Most independent reputable contractors in So. Cal have been in business around 10-15 years, should I be considering a large company and pay more?
Which aforementioned offer seems to be the best deal?
Am I missing anything here?

In advance, thanks for the assistance.
Al.

[ButchDeal]

Are your prices after incentives?
you are confusing kw and kWh
your annual consumption is 6400 kWh

the systems are sized in kw though you listed them as 6400kw that is really 6.4kw ( 20 X 320w = 6400 w = 6.4kw)

as for for south VS west roof, production on west will be reduced by 15-20% for west face ( assuming no difference in shadows)
though west face will produce latter in the day helping with time of use billing.

why are all your options with micro inverters?

[Kendalf]

namelama I'm in So Cal and our system just went live this week. We have slightly higher annual usage (~9000kWh annually for our family). We installed 21 Panasonic N315K "all black" panels. I personally would have preferred the higher efficiency N325/N330 Panasonic panels with the white backing, as the all-black does lead to higher temperatures (and lower efficiencies), but the installer we ended up choosing had best pricing with the all-black panels as that is what they had stocked up on.

We had the panels installed with a SolarEdge 6kW inverter w/ P400 optimizers, and our final $/W was $2.87/W. Our front roof is exactly south facing and that's where we had the panels installed. The all-black panels look nice, but TBH I doubt many people spend too much time looking at the PV array on the roof of people's houses (except when they are in the process of considering purchasing a solar system). Our installer added a black front skirt to block the view of the racking from the front. I've attached an image so you can get an idea what it looks like, if your concern about mounting on the South facing roof is due to aesthetic reasons. Without knowing any details of your roof, but my guess is that you would need a lot more panels for just a west facing system to match the overall output of the systems that are facing South.
IMAG0239.jpg

It looks like all your quotes are using microinverters. Have you asked for quotes from companies that use SolarEdge optimizers and inverters? Costs tend to be a bit lower than microinverters.

In regards to your question about local vs larger companies, I did get a quote from Tesla/SolarCity as well as a couple of the largest So Cal solar companies, but we ended up choosing a smaller local company that has not been around for as long as some of the others (10 years) but had a good reputation locally.

Are the two independent contractors that you mentioned actual solar installers, or do they just do solar installs on the side by themselves?

[namelama]

Thanks for clearing those things up. Regarding the micro inverters, I preferred micro inverters because our last system had one big main inverter on the wall which was not appealing and I also couldn't identify if a panel wasn't producing vs the system is not producing as much. I would be able to isolate each panel, my preference. All prices are before incentives.

[ButchDeal]

Thanks for clearing those things up. Regarding the micro inverters, I preferred micro inverters because our last system had one big main inverter on the wall which was not appealing and I also couldn't identify if a panel wasn't producing vs the system is not producing as much. I would be able to isolate each panel, my preference. All prices are before incentives.

You should know that You have better monitoring with SolarEdge.

[namelama]

The Independent installers are local (Menifee and Aliso Viejo). Menifee guy has a lot of Yelp reviews and the Aliso Viejo guy I previously used. Not a fan of Solar World panels if I can get LG's for about the same price. You're correct, I'll need an additional 3 panels for the west facing install. Your 2.87 price is really good.

[Kendalf]

Thanks for clearing those things up. Regarding the micro inverters, I preferred micro inverters because our last system had one big main inverter on the wall which was not appealing and I also couldn't identify if a panel wasn't producing vs the system is not producing as much. I would be able to isolate each panel, my preference. All prices are before incentives.

The new SolarEdge HD-wave inverters are actually relatively compact, probably significantly smaller than the inverter you had in the past. Also, with optimizers you can get panel level monitoring.
IMAG0218.jpg

[namelama]

How is the SolarEdge better monitoring?

[J.P.M.]

For starters, those system sizes are in thousands of watts, not thousands of kW.

Next: Why are your proposed systems so large ?

Your annual load is ~ 6,400 kWh/yr. Aside from the likely reality that a 100% offset of your load may not be as cost effective as a < 100% annual offset, in/around most of So. CA, a 6,400 kWh annual load can be 100% offset by a system that's about 4 S.T.C. kW in size, maybe a bit more. If what you are reporting for an annual load is correct, and your shading and orientation are as you say, those vendors are way oversizing to the point of being way unethical.

Before you do anything else, get and read a copy of "Solar Power Your Home for Dummies" at bookstores or Amazon. You need an education, if only for self defense against getting screwed as you will be if you listen to who you've got quotes from so far. You'll also way overpay if you believe the Sunpower hype and go with that panel. Good stuff, but no more fit for purpose than other quality products costing a whole lot less.

PV equipment is now a commodity. Sunpower is the Mercedes. You will do quite nicely with the equivalent of a Ford or Toyota.

With no shade, you have nothing to gain by using microinverters except more failure points (one inverter per panel instead of one inverter for the entire system), with all the electronics in a harsh environment (your roof) and pretty much inaccessible, rather than one inverter that you can walk up to and service if needed. BTW, microinverter systems usually cost ~~ $0.10 - 0.20/S.T.C Watt more than string inverter systems. For that you get more complication, a lot more temp. sensitive electronics on a mostly inaccessible roof and the lower reliability that goes will all that. Such a deal.

Any peddlers talk annual savings to you ? If so, make sure they are using the new net metering tariffs and NOT old estimates using OLD rates. Residential PV is about 20-25 % less cost effective than it was a year or 2 ago because of CPUC revisions that allowed POCOs (POwer COmpany) to shift folks over to Time of Use (T.O.U.) metering with peak times that are much less favorable to PV economics. Peddlers usually leave that part out.

I'd not worry about warranties. Panels seem quite reliable. If you're like me, you'll probably be dead or moved before a panel fails (but maybe not so for microinverters BTW).

On appearance: In spite of what you may think, you'll most likely stop looking at and noticing your array after a week or two as will your neighbors. All black may look nice, but beauty is in the eye. Besides usually costing a bit more, all black also comes with a slight performance penalty as all black tend to run just a bit hotter. So "2001: A Space Odyssey" comes to your roof for a premium price and lower output. Such a deal.

You should be pricing in $/watt, but NOT initial $$ alone. Think most bang for your buck. This is important and a long way from low initial price. Buy cheap, buy twice.

Spend time evaluating vendors and forget crap like yelp, Angie's list and even the BBB. They're sellouts, and/or with reviews/comments from people who don't know anything about what they bought except maybe that the salesperson smiled a lot making such information less than useless. Basically, you're on your own. That's one big reason why it's important that you get educated (the book), then fill in information gaps with questions here. Learn and understand how PV works, its capabilities and limitations, and how to get the most bang and quality for your buck. Then, run something called PVWatts. It's a user friendly residential sizing model from NREL. Read ALL the help screens a couple of times, then get your orientations correct, Use 10% system losses (you'll figure what that is from the help screens) and do a few runs. About 20 minutes/half an hour and you'll understand what's required. Just read the book first. Depending on where you are in So. CA, you'll probably find that, as I suggested above, a 4 S.T.C. kW system will generate somewhere in the vicinity of 6,400 kWh/yr.

As to which of your listed systems is the best deal: Short answer is they are all oversized so they all suck. Sunpower is good quality but almost always overpriced for what they provide and what's needed. Better question is: How to find a quality vendor with some integrity who will provide a quality installation using fit for purpose equipment for the best long run cost effective price ?

To do that, take all your new knowledge and then study up on how you are charged for electricity. That's the biggest PITA of this whole exercise but important to help get you the most cost effective size and system. The rate info and rate plan options are available from your POCO, but don't expect much help from the POCO in understanding any of it. Again, you're on you own. Sorry I can't be more positive about that. Just remember that nothing can replace persistence.

Depending on where in So. CA you're located, you'll probably find that a 4 S.T.C. kW south facing unshaded system will produce about 6,400 kWh per yr. or so.

After all that, formulate a bunch of questions that you already know the answers to by virtue of your recent education and call some vendors of non Sunpower equipment. Then, ask your chosen vendors your questions. You'll get another education in the form of their answers. That education being in the form of what they (don't ?) know. Use those answers and your gut to choose the vendor that you feel will give you the best quality equipment and, equally or more importantly, the best installation quality. Negotiate tough, but fair and remember two things: Every thing is negotiable, but a few pennies per watt for quality work is about the cheapest insurance you can buy.

Also, get your roof inspected and serviced as necessary. More cheap insurance. Finding leaks or fixing a roof under an array is expensive and a real PITA. PV will last a long time on your roof. Give the roof the best/highest probability of lasting as long. You will not regret the extra expense. Payback on that comes in the form of peace of mind during the first big rainstorm. Believe it.

Add: almost forgot, between west facing and south facing orientations, if you will be on the new T.O.U. rates and times (as you probably will), a south facing array will, in all likelihood produce more revenue offset than will a west facing array. I know that may seem counterintuitive, as you may think once you get into POCO rates, but the most bill offset under most POCO T.O.U. tariffs is with an array azimuth of ~ 205 to 225 deg. and ~ 20 - 30 deg. tilt. For other orientations, without shading, dead south will beat dead west for SDG & E rates, and from what I know of the similarities to other So.CA POCO rates, I believe the same holds true for them.

Welcome to the neighborhood and the forum of few(er) illusions.

Take what you want of the above. Scrap the rest.

[namelama]

Thank you for the response and I'll buy that book. Seems like an education I need.

[J.P.M.]

Thank you for the response and I'll buy that book. Seems like an education I need.

You're most welcome. As you go through this process, question everything everyone says (even and maybe especially me) until you understand what you're being told. None of us is as smart as all of us. Knowledge is power. In this case, the power to avoid getting completely screwed. The book is ~ $20 and money well spent.

Good luck

[J.P.M.]

Thanks for clearing those things up. Regarding the micro inverters, I preferred micro inverters because our last system had one big main inverter on the wall which was not appealing and I also couldn't identify if a panel wasn't producing vs the system is not producing as much. I would be able to isolate each panel, my preference. All prices are before incentives.

Bet you'll stop looking at the output very quickly. if so, one panel out will likely go unnoticed a lot longer than a string or an entire inverter. Believe it.

Oh yea: Try to get at a micro that's in the middle of an array. Lots of labor. Everything moved/disconnected gets hooked up correctly ? Many micro warranties exclude part or all labor.

Also, that skirt Kendalf shows inhibits air circulation under the array. That raises array temp. That temp. increase decreases array efficiency and therefore array output. That makes things less cost effective. Kendalf:: You just shot yourself in the foot. As an added bonus, the higher temps make things more failure prone, and you paid more to do it.. Suit yourself. not my array/house/money/life, but it's an array for God's sake, not a fashion statement. It's an appliance like a garage door opener or a water heater, not a lifestyle.

[ButchDeal]

How is the SolarEdge better monitoring?

Better pv module level and free for life.

[Kendalf]

Also, that skirt Kendalf shows inhibits air circulation under the array. That raises array temp. That temp. increase decreases array efficiency and therefore array output. That makes things less cost effective. Kendalf:: You just shot yourself in the foot. As an added bonus, the higher temps make things more failure prone, and you paid more to do it.. Suit yourself. not my array/house/money/life, but it's an array for God's sake, not a fashion statement. It's an appliance like a garage door opener or a water heater, not a lifestyle.

I'm all for maximizing efficiency and reducing temperatures. That said, I agreed to the front skirt because it is only attached to the front (South) edge of the array; the sides and top are still open. The wind that we get is about 95% East to West or West to East, so the breeze will still flow mostly unhindered underneath the array, and heat can still go out from the top of the array via convection. The front skirt is also not flush with the roof, leaving a 2-3 inch space for some airflow to enter from the front. I also didn't ask for the skirt nor was it an added cost in the BOM.

If I'm not satisfied with array performance in the summer, and suspect it is due to higher temps, I may try to unscrew the skirt and see if that improves anything. As it is, I've been happy with the array performance so far as I indicated in another thread, with a 7.12 kWh/kW(DC) efficiency over the course of the first full day of data when highs were 85F.

[J.P.M.]

I'm all for maximizing efficiency and reducing temperatures. That said, I agreed to the front skirt because it is only attached to the front (South) edge of the array; the sides and top are still open. The wind that we get is about 95% East to West or West to East, so the breeze will still flow mostly unhindered underneath the array, and heat can still go out from the top of the array via convection. The front skirt is also not flush with the roof, leaving a 2-3 inch space for some airflow to enter from the front. I also didn't ask for the skirt nor was it an added cost in the BOM.

If I'm not satisfied with array performance in the summer, and suspect it is due to higher temps, I may try to unscrew the skirt and see if that improves anything. As it is, I've been happy with the array performance so far as I indicated in another thread, with a 7.12 kWh/kW(DC) efficiency over the course of the first full day of data when highs were 85F.

Anything that inhibits or reduces free air movement around, over and under an array will have a cost in terms of performance by affecting natural (bouyancyyancy induced) convective heat transfer and forced convective (wind) heat transfer. The two act simultaneously with forced convection usually being the larger of the two, often by an order of magnitude. Those air movement reductions will cause an increase in array temp. The restriction on the lower edge will, depending on wind direction, reduce the free flow area either into or out of the space under the array. It may be a small effect and not even measureable, or it may be larger. Point is, it will have a performance penalty and it's user initiated.

Given the idea that one big goal of getting PV is to reduce electric bills, one good way to meet that goal is not to do anything that reduces efficiency. Inhibiting air flow reduces efficiency. In terms of aesthetics, everyone has a opinion and they're all different, but once you make a statement and put a big black slab of several hundred ft.^2 on a roof, seems like the style battle has been irretrievably lost. At that point, putting a skirt around the bottom of a roof mounted array seems kind of like thinking your pig can win a beauty pageant if you put a tutu around it that the pig then trips over during a runway performance.