New Member - Requesting Advice on Estimates

[dcchapman7]

Have been doing a lot of research on solar the last few weeks, getting bids, running system sizes through PVwatts - some background before asking about the estimates I got: my home is in Fresno, CA, 2069 sq ft, our annual consumption was 9400 kwh last year, average monthly electric bill with PG & E about $155 (annual cost - $1860). Our only options for a roof mount are east and west facing due to very large trees in a neighbors yard that shade the south side of the house - these trees eliminate the option of installing on that end and also do bring some shade on the east and west sides especially in the winter. We are interested in an larger system that would produce well above our current consumption (margin enough to offset the electrical costs of running a hot tub - those we've talked to have suggested an extra 100-200 kw/mth more?) Think I have narrowed down quotes to 2 companies at this point - here are the details:

Option A) 8.8 kW system - Canadian Solar 325W - (CS6X-325p) - 27 panels
with Solar Edge inverter and optimizers
Cost - $24,132 - $2.74/W
Company has been around since 2008 - fairly solid reviews

Option B) 8.8 kW system - Hanwa 340W - (Q.Plus L-G4.2) - 26 panels
Solar Edge inverter and optimizers or Enphase microinverters
Cost - $21,780 - $2.47/W
Company has been around since 1970 - solid reviews (does heating and air conditioning, started doing solar around 2008)

Questions with the estimates -

1) Canadian Solar vs. Hanwa - thoughts on if Canadian Solar is worth the extra cost? Either companies' viability? Thoughts on if these are good prices for either brand?

2) Solar edge inverter with optimizers vs. enphase microinverters - have been advised by Company A not to go with microinverters due to temperature extremes in Fresno, that they will inevitably fail even though they have been tested in extreme temp environments and also there would be multiple points of failure instead of just one. It sounds like from the reading I've done, optimizers have less electronics in them and are less prone to fail. Company B will do either microinverters or optimizers for us, but have mostly used microinverters and they do offer a 25 year complete warranty on all parts and labor. Which do you think is the better choice? Is there an advantage to either with our shading issues?

3) Regarding running a hot tub, is the system sized too big or too small or just right based on our current usage?

4) We have an attached Duralum patio cover on the west side of the house big enough for 13 panels, am in the process of having one of the companies check with the county (with whom we pulled a permit when the patio cover was installed in 2014) if the engineering is sufficient to support the weight of the panels. Have considered that installing on the west facing patio cover would mean more production during peak TOU hours (with NEM 2.0), but then not sure about need for tilting panels on the patio cover due to only about 2.5% slope of cover (PVwatts actually shows better production with zero tilt than 20 degree - our roof pitch is 4-5/12). It sounds like tilting would be wise as far as the panels staying cleaner and that tilting should enable better production overall?...not sure what I'm' seeing on PVwatts then...If installing on the patio cover is an option, what are your thoughts on doing this vs on the east facing roof? One of the companies mentioned having all the panels installed on the west side being better for resale if the patio cover is an option...

Sorry if the post is too overloaded with info, wasn't sure how much detail to give or how many questions to ask in the first post. Appreciate any feedback and thoughts.

[cebury]

1. The difference in prices are probably installers and not between the panels. Last I checked the hanwa had two more years of warranty, but he Canadian Solar had some kind of guarantee if they went under. Given equal costs, the talk around here has been they are both fine.
2. I avoided micros for the same reason. Lemme, guess company b is Mr. Cool. Donald P.Dick.

[dcchapman7]

If this did happen to be the company, recommend or not? Don't know if it's okay to ask that or not on the forum...

[solar pete]

Its Ok to ask about or mention solar installers, we just ask that you dont link to their website or provide any contact details etc, it is OK to link to the installers www.solarreviews.com page, if you feel you want to, cheers.

[dcchapman7]

Any thoughts on the questions/estimates solar pete? Or same as cebury?

[cebury]

Sorry didn't get around to finishing response. The only thing I knew about mr.cool is they were much more expensive than all my other quotes and really pushed micros. They also are not a fully integrated company. When they started solar, they formed a new company so that it could be shutdown when the market bubble pops and customers have no recourse against their long established main company. I would not be afraid of them for that reason, but don't let them sell you on "we are in it for long term."

I went with Canadian Solar panels SolarEdge via Solar Negotiators (a sales company led by Moran who knows his stuff) and I paid under $3/Watt DC in Oct. 2015. Contracted with 4th Day www.solarreviews.com/installers/4th-day-energy-reviews/
No regrets and they fixed one solaredge module that died, no questions asked although it took two emails. They had the best price and did extra work for much cheaper than competitors estimated. Back then, Arise was also close in price and we'll vetted. Just be upfront you dont want Sunpower, otherwise they might offer first.

I have no idea how to answer #3.

My 7.28kw South facing 5/12 system hit almost exactly, within 10 dollars at TrueUp, where I estimated to offset my bill 100% dollars (not kwh), accounting for pge minimum 120/yr payment. I was a net user of PGEs power by 850kwh that year. My numbers were about $2500/yr or almost 13000kwh/yr at 2016 rates. That really doesn't help you much since your arrays are different.

Amin note, I just edited out the reference to a solar company that does the same as our site sponsor's www.solarreviews.com and www.solar-estimate.org, cheers.

[solar pete]

Any thoughts on the questions/estimates solar pete? Or same as cebury?

Yeah in agreement with cebury, it sounds like your on the right track, cheers.

[cebury]

And you might surprise me, but don't count on getting back a Yes or no from the AHJ on adding solar to your patio. They are high level, meaning they will review the stuff You pay for and give ok that it's in order. They may require you to get an engineering OK first on the patio, once then to read the specs that you paid to put together, then they give you an OK.

I'm not sure what you are seeing either with zero tilt West facing panels producing more than titled. That would surprise me, but others here would know if that's possible.

Both the city and county inspectors are wrong sometimes, so sometimes you have to push. They told me I couldn't replace my open fireplace with a wood burning stove, absolutely not. Wood burning bad. Even though it epa phase2 cert. They were so wrong in fact, the air district pays a 1000 rebate to anyone who does it. They mix up their facts from time to time for new home builds vs retro and for Valley vs, mountainous region code. But I argued with every inspector there even showing them the rebate and the answer from the county air district, yet got "well, I know it's not true".

[J.P.M.]

I'm not sure what you are seeing either with zero tilt West facing panels producing more than titled. That would surprise me, but others here would know if that's possible.

For many, perhaps even most locations in the U.S., horizontal panels (with panel "azimuth" thus having no meaning at a horizontal tilt), will, depending on the particular combination of azimuth and tilt under consideration, produce more annual output than a tilted panel at off south orientation.

Run PVWatts for Fresno. For 20 dg. elevation and 270 deg. az., it's close, but horizontal is still slightly better. FWIW, that's still not a reason to do horizontal panels.

[dcchapman7]

Are the main disadvantages for horizontal panels dust and dirt accumulation, thus lower production and need for frequent cleaning? Other disadvantages? If I did install on the patio cover, minimum tilt recommendations? 20-30 degrees?...

[J.P.M.]

Are the main disadvantages for horizontal panels dust and dirt accumulation, thus lower production and need for frequent cleaning? Other disadvantages? If I did install on the patio cover, minimum tilt recommendations? 20-30 degrees?...

The short answer is no, but those are still important considerations. The biggest disadvantage for a horizontal orientation is that it is usually not the most optimum orientation for a solar panel in terms of annual production. The fact that horizontal panels will not be as clean because dust/dirt will tend to stay put adds to the reduction in annual performance making array fouling an additional consideration. And, they will also require more frequent cleaning.

So, annual and overall performance of horizontal panels will suffer for at least 2 reasons that other orientations will TEND to not be botrhered by AS MUCH: Lousy orientation and the fact that they will get dirtier quicker and tend to stay that way.

Given a choice of a horizontal orientation or an equator facing tilt at latitude, once you're outside a tropical latitude, the tilted array will almost certainly and always outperform a horizontal array.

Now, on a horizontal roof, or horizontal elevated structure, the tilt angle decision is a bit more complicated. Aside from the usual loading considerations for tilted roofs, tilting panels on a horizontal roof can require additional loading considerations for wind and seismic, and perhaps snow loading distribution (drifting) considerations (but not snow loading for Fresno) that can be and usually are different and quite often more severe when all required and/or possible loading combinations are considered than those that may be applicable for a monolithic array that is parallel to the roof it's mounted on.

[dcchapman7]

Here are shots of the west facing patio cover just to give an idea of what it's like...if it were you would you still put the 13 panels on the east facing roof?

[dcchapman7]

Here is a roof top view.

[Mike90250]

Here are shots of the west facing patio cover just to give an idea of what it's like...if it were you would you still put the 13 panels on the east facing roof?

i'd run it through PV watts West @ 10deg tilt, vs East @ ?? deg tilt. It depends on your local conditions, more clouds AM than PM? Shading of one side vs other...

[dcchapman7]

I ran it through PV watts - for installing the 13 panels on the west facing patio cover with 10 degree tilt and 20% losses,output is 5738 watts, an installing them on the east facing roof with 22 degree tilt and 20% losses is 5590 watts... thoughts?