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Re: Solar Installation - 0.75 Year Later

Posted: Wed Oct 09, 2019 12:54 pm
by mervinj7
curmudgeon wrote:
Wed Oct 09, 2019 10:37 am
There is one string inverter (the older "Sunny Boy") that I'm aware of which has an option for an outlet at the inverter box which can remain powered during utility outages. If you ran an extension cord around the house, 10 hours or so of power during the day would probably be enough to at least avoid losing the contents of your fridge. I thought it was a little gimmicky, and didn't go down that route :( I suspect trying to retrofit some properly engineered/permitted solution like that to my micro-inverter system would be pretty costly.
We thought about adding a LG Chem battery pack when we did our solar install but the ROI wasn't there. Initial quotes were for $7.5k for a single Powerwall install after incentives. Unlike everything else in the system, the batteries only have a ten year warranty and the arbitrage opportunities are limited with net metering. That said, a year ago I never imagined that we would have a situation where more than 500k 800k 1M people in the state of CA would have planned blackouts that could potentially last up to 5 days. I've had 6 outages during the last two years but none were more than 4 hours and most were under 10 minutes. If battery prices drop a bit more and if easier retrofit options become available, then we'll seriously consider retrofitting our existing setup with a battery backup.

https://www.usatoday.com/story/news/nat ... 916848002/

Re: Solar Installation - 0.75 Year Later

Posted: Wed Oct 09, 2019 2:55 pm
by baconavocado
mervinj7 wrote:
Mon Oct 07, 2019 11:36 am
baconavocado wrote:
Wed Oct 02, 2019 6:12 pm
We've been putting this off because our roof is older but I think we're going to need a new roof next year, so we'll probably look into solar. Do you know what the credits will be next summer?
I think I misunderstood you question but if you are talking about the Federal residential energy incentive (not the PG&E tariffs), it is stepping down over the next several years.

2019: 30%
2020: 26%
2021: 22%
2022: 0% (assuming no legislative change)

https://www.irs.gov/newsroom/energy-inc ... nd-answers
Thanks, that's exactly what I was wondering about.

Re: Solar Installation - 0.75 Year Later

Posted: Wed Oct 09, 2019 3:13 pm
by TomatoTomahto
mervinj7 wrote:That said, a year ago I never imagined that we would have a situation where more than 500k 800k 1M people in the state of CA would have planned blackouts that could potentially last up to 5 days.
That’s one thing that factored into my decision to install Sonnen butteries (in MA, not CA). Generals prepare to fight the last war, and so do homeowners. We get a fair number of outages in MA, but the longest in the time we’ve lived here has been for a day. So, even with SMART credits for a battery that gets exercised once a week, and the 30% federal tax credit, it doesn’t really make sense on a spreadsheet, UNTIL you assign a value to being able to stay warm in a polar vortex for a few days in an all electric house.

Re: Solar Installation - 0.75 Year Later

Posted: Wed Oct 09, 2019 6:13 pm
by mchampse
We live in the Bay Area and signed a contract for a solar system several months ago. They aren’t certain that they can do the installation before the end of the year. Presumably some combination of the federal credit getting lowered and the blackouts has caused demand to spike. We went with a battery to get us through any black outs.

Re: Solar Installation - 0.75 Year Later

Posted: Sun Oct 13, 2019 12:16 am
by canon_shooter
My system data for the SF Bay Area (San Jose).

One unanticipated benefit on my part was the savings on gas as we purchased an EV after the solar was installed. After 25K miles I've saved about 4K on gas. This significantly reduces payback time.

I was able to deduct sales tax by getting an estimate on the materials cost (13K).
I was told (after install) and when getting solar at the same time as new roof, one can allocate to the solar cost, the area under the solar panels in terms of any rebates. It was too late for me, but something to look into.
A benefit is that I can run the air conditioner on the rare occasions I need it without worrying about cost.

Quoted Cost: 26,435
Federal Tax Credit: 7,931
Post Tax Credit Cost: 26,435 - 7,921 = 18,504

Estimated Cost Savings by installer $3,293

Breakeven: 18,504/3,293 = 5.6 years

Production Data:
Estimated by Installer: 10,594 kWh/year (883 kWh/month)
Actual: 27.48 MWh Apr 18, 2017 – Oct 12, 2019 =29 months
or 947.5 a month or 11.3 MWh/year

Extra benefit unanticipated
Not paying for gas:. (25,000/22MPG) * $3.50/gal = $3,977

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 12:34 am
by jjj240
mervinj7 wrote:
Thu Oct 03, 2019 10:55 am

Unfortunately, I can no longer find a link to the spreadsheet but his guide is still up.

The following was a screenshot of my analysis pre-install assuming a flat $0.29/kWh rate. However, the IRR and NPV are already incorrect since TOU rates will change substantially in five years.
Image
Could you share the spreadsheet? TIA

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 12:44 am
by burgertimer
mchampse wrote:
Wed Oct 09, 2019 6:13 pm
We live in the Bay Area and signed a contract for a solar system several months ago. They aren’t certain that they can do the installation before the end of the year. Presumably some combination of the federal credit getting lowered and the blackouts has caused demand to spike.
What company is delaying you 5 months?

I plan to sign a contract tomorrow with a roofer, and they claim they can do the roof and panels within 8 weeks.
Panasonic 19% efficiency panels, enphase micro inverters.

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 3:28 pm
by mervinj7
jjj240 wrote:
Tue Oct 15, 2019 12:34 am
mervinj7 wrote:
Thu Oct 03, 2019 10:55 am

Unfortunately, I can no longer find a link to the spreadsheet but his guide is still up.

The following was a screenshot of my analysis pre-install assuming a flat $0.29/kWh rate. However, the IRR and NPV are already incorrect since TOU rates will change substantially in five years.
Image
Could you share the spreadsheet? TIA
Here's a copy I made.
https://drive.google.com/file/d/1ozJZK8 ... sp=sharing

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 5:22 pm
by shans2000
My solar panels were installed 5 yrs ago, and they are generating 30-50% of the originally quoted power. Does anyone know if this is common and what can be done to improve this?

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 5:33 pm
by Nate79
shans2000 wrote:
Tue Oct 15, 2019 5:22 pm
My solar panels were installed 5 yrs ago, and they are generating 30-50% of the originally quoted power. Does anyone know if this is common and what can be done to improve this?
Warranty?

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 5:43 pm
by curmudgeon
shans2000 wrote:
Tue Oct 15, 2019 5:22 pm
My solar panels were installed 5 yrs ago, and they are generating 30-50% of the originally quoted power. Does anyone know if this is common and what can be done to improve this?
A couple of basic factors: Are they reasonably clean? (not covered with soot/dirt). Have trees grown up that are doing substantial shading? Also realize that right now we are well off of peak production sunlight (June/July).

Does your monitoring allow you to check individual panel outputs? Perhaps there have been some failures.

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 5:57 pm
by mchampse
burgertimer wrote:
Tue Oct 15, 2019 12:44 am
mchampse wrote:
Wed Oct 09, 2019 6:13 pm
We live in the Bay Area and signed a contract for a solar system several months ago. They aren’t certain that they can do the installation before the end of the year. Presumably some combination of the federal credit getting lowered and the blackouts has caused demand to spike.
What company is delaying you 5 months?

I plan to sign a contract tomorrow with a roofer, and they claim they can do the roof and panels within 8 weeks.
Panasonic 19% efficiency panels, enphase micro inverters.
A company called which operates in the city. They are a reseller for Solae City. To be honest I had trouble even getting companies to respond to give me a quote. I might write into the contract that they will give you a 4% discount if it’s not completed by year end.

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 7:03 pm
by shans2000
curmudgeon wrote:
Tue Oct 15, 2019 5:43 pm
shans2000 wrote:
Tue Oct 15, 2019 5:22 pm
My solar panels were installed 5 yrs ago, and they are generating 30-50% of the originally quoted power. Does anyone know if this is common and what can be done to improve this?
A couple of basic factors: Are they reasonably clean? (not covered with soot/dirt). Have trees grown up that are doing substantial shading? Also realize that right now we are well off of peak production sunlight (June/July).

Does your monitoring allow you to check individual panel outputs? Perhaps there have been some failures.
I don't have monitoring or warranty information since this was installed by previous owner, I will look into cleanliness.

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 7:46 pm
by canon_shooter
Shans,

I have micro inverters for every one of my 22 panels. I ran an experiment last year where I left 2 of the panels uncleaned. That is, every year I get on the roof and clean the panels with a soft brush except for 2. The panels I was testing get equal solar illumination. I found a 5% difference between the clean panels and the uncleaned panels. I believe someone here posted an 8% difference, but it depends on a number of factors such as pollution, dust, soot, pollen, bird droppings, leaves etc. Based on my research 5% seems to be about normal. So, the drop in production you are seeing cannot be explained by dirt.

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 15, 2019 8:21 pm
by curmudgeon
shans2000 wrote:
Tue Oct 15, 2019 7:03 pm
curmudgeon wrote:
Tue Oct 15, 2019 5:43 pm
shans2000 wrote:
Tue Oct 15, 2019 5:22 pm
My solar panels were installed 5 yrs ago, and they are generating 30-50% of the originally quoted power. Does anyone know if this is common and what can be done to improve this?
A couple of basic factors: Are they reasonably clean? (not covered with soot/dirt). Have trees grown up that are doing substantial shading? Also realize that right now we are well off of peak production sunlight (June/July).

Does your monitoring allow you to check individual panel outputs? Perhaps there have been some failures.
I don't have monitoring or warranty information since this was installed by previous owner, I will look into cleanliness.
It might be worth starting a new, dedicated thread for this. It's unfortunate that you didn't get key documentation from the previous owner; your RE agent didn't handle that well. You should start by gathering what information you can find at ground level. Try to understand what type of system you have, and whether it had some built in monitoring which may now not be working because you brought in your own wifi and router. If you have to, you might be able to get copies of the detailed plans which were submitted for the building permit needed when the solar system was installed.

There are a number of variations in home solar power installations, so a few more details would help people help you.

Re: Solar Installation - 0.75 Year Later

Posted: Sun Oct 20, 2019 10:16 pm
by jjj240
canon_shooter wrote:
Sun Oct 13, 2019 12:16 am
My system data for the SF Bay Area (San Jose).

Production Data:
Estimated by Installer: 10,594 kWh/year (883 kWh/month)
Actual: 27.48 MWh Apr 18, 2017 – Oct 12, 2019 =29 months
or 947.5 a month or 11.3 MWh/year
It would be helpful If you could provide system details, # of panels, model, inverter model, azimuth, tilt, and installation zipcode.

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 22, 2019 10:43 am
by LISD
Mervin, did your total costs include a totally new electric panel, or did they just add a smart-solar device to your existing panel?

Thanks,
Larry

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 22, 2019 11:59 am
by wilked
I have a question

Solar installed and live since a couple months. 20 panels. Roof is dead south, pitch is 10/12, and no trees or obstructions at all.

One panel of the 20 is producing about 10% less than the others. I have a single inverter (Solaredge 5000).

My questions:
-Do you think it is shading that is causing it? The 'sister' solar panel on the other side of the dormer is spaced the same distance away from the dormer as this one is - I would think if it's shading it would affect both of those panels?
-Does one low-performer affect the others? Getting mixed messages on this via googling. The others seem to be doing fine so I think that means no, just wondering
-Anything to worry about? As long as the total system is performing to spec really doesn't matter, no? How do I determine if the 'net' is meeting the spec output? It was spec'd as a 6.2kW system with 8150 kw-h/yr production.

https://i.imgur.com/InkDrs1.jpg
https://i.imgur.com/DWSYcBy.jpg

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 22, 2019 12:45 pm
by curmudgeon
wilked wrote:
Tue Oct 22, 2019 11:59 am
I have a question

Solar installed and live since a couple months. 20 panels. Roof is dead south, pitch is 10/12, and no trees or obstructions at all.

One panel of the 20 is producing about 10% less than the others. I have a single inverter (Solaredge 5000).

My questions:
-Do you think it is shading that is causing it? The 'sister' solar panel on the other side of the dormer is spaced the same distance away from the dormer as this one is - I would think if it's shading it would affect both of those panels?
-Does one low-performer affect the others? Getting mixed messages on this via googling. The others seem to be doing fine so I think that means no, just wondering
-Anything to worry about? As long as the total system is performing to spec really doesn't matter, no? How do I determine if the 'net' is meeting the spec output? It was spec'd as a 6.2kW system with 8150 kw-h/yr production.
I suspect it is seasonal dormer shading effect. You may find that in the spring, the panel on the other side has the slightly lower production. If you can take a look at the instantaneous output at different times of the day, you may be able to see the shading effect in morning or evening.

Solaredge installs normally have an "optimizer" at each panel, which should prevent any impact to production on the other panels. It could be possible that you have a bad optimizer or panel, but since it's the one by the dormer, I'd lean towards shading as the cause.

You won't really see peak production until next June, and the annual production is somewhat subject to weather effects (cloud cover), but that should be included in the design calculations.

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 22, 2019 2:17 pm
by wilked
Thanks!

Good point on spot checking different points in the day - will do

Re: Solar Installation - 0.75 Year Later

Posted: Tue Oct 22, 2019 3:11 pm
by mervinj7
LISD wrote:
Tue Oct 22, 2019 10:43 am
Mervin, did your total costs include a totally new electric panel, or did they just add a smart-solar device to your existing panel?

Thanks,
Larry
I already had a "solar ready" 200A panel. There's no smart device inside the panel. They just added a regular 40a double pole breaker that runs directly to the inverter.

Re: Solar Installation - 0.75 Year Later

Posted: Wed Oct 30, 2019 6:20 pm
by jjj240
mervinj7 wrote:
Wed Oct 02, 2019 5:56 pm

System Summary:
Location: Bay Area, CA
Panels: 22 x 330W Panasonic HIT→ 7.26kW
Inverter: SolarEdge SE10000HD (Oversized for future expansion)
Warranty
  • 25 Year on Panasonic Panels
mervin7,

According to webpage below, Panasonic 25 yr warranty is applicable for system installation performed by Panasonic Authorized or Premium Installer AND registered within 60 days.

https://na.panasonic.com/us/form/produc ... solar-form

1) Does it mean DIY installation (or any non-authorized installer) won't be covered for 25yr warranty?
2) Is your warranty through Panasonic? i.e. met both conditions. Or is it warrantied though your installer?

Re: Solar Installation - 0.75 Year Later

Posted: Wed Oct 30, 2019 6:26 pm
by mervinj7
jjj240 wrote:
Wed Oct 30, 2019 6:20 pm
mervinj7 wrote:
Wed Oct 02, 2019 5:56 pm

System Summary:
Location: Bay Area, CA
Panels: 22 x 330W Panasonic HIT→ 7.26kW
Inverter: SolarEdge SE10000HD (Oversized for future expansion)
Warranty
  • 25 Year on Panasonic Panels
mervin7,

According to webpage below, Panasonic 25 yr warranty is applicable for system installation performed by Panasonic Authorized or Premium Installer AND registered within 60 days.

https://na.panasonic.com/us/form/produc ... solar-form

1) Does it mean DIY installation (or any non-authorized installer) won't be covered for 25yr warranty?
2) Is your warranty through Panasonic? i.e. met both conditions. Or is it warrantied though your installer?
I don't know about the DIY option but both conditions were met for 2. That does limit your installer choices, though.