Photograph via snooOG

Discussion of solar photovoltaic systems, modules, the solar energy business, solar power production, utility-scale, commercial rooftop, residential, off-grid systems and more.

Solar photovoltaic technology is one of the great developments of the modern age. Improvements to design and cost reductions continue to take place. How efficient will it become? When will it become so affordable that it's accessible to everyone? How are other energy industries having an effect on solar pv?

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This subreddit is for solar photovoltaic (PV) professionals, owners, and enthusiasts. The solar module and the systems it drives - whether small residential installations or large, utility-scale power plants - is one of the great inventions of the modern age. Steady improvements in materials, design and labor have dramatically lowered costs, module efficiencies have improved gradually as well - both serving to make the technology much more competitive against fossil fuels in recent years. What changes when solar PV is combined with batteries? What is the global impact of solar PV on the overall energy industry? When will solar become affordable for all? Shine on you brilliant solar enthusiasts!

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Solar Job Training Resources

* The Solar Career Mapping Tool - This is an interactive Solar Career Map offered by the Interstate Renewable Energy Council (IREC). It is designed for workforce professionals, educators, policymakers and job seekers. See - http://www.irecsolarcareermap.org

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Find the latest Help Wanted feature post HERE which includes links to several industry job listing sites


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Using rooftop solar on my company’s factory

We have about 50,000m^2 of rooftop space available, I would like to pitch a rooftop Solar project. This is in Central Pennsylvania, what kind of panels should I use, and how many would I need to fill up the space? Any commercial tax rebates the company would receive?

13:29 UTC


Solar consultation appointment help (NY) Wrote a $500 check

So I had a consultation appointment with a company called ‘3rd ROC Solar’. I live in Western NY and the company operates out of the Rochester area. The guy did a lap around my house and was instantly frothing at the mouth it seemed* like. He was very ecstatic about my “South facing roof, and the amount of space”. He was extremely happy that my meter is new (replaced like 5 months ago). That my fuse box was 210 and had 6 open fuse slots. We then sat at my dining room table* and he had his computer out and went through the motions showing me that I qualify for a state loan at 3.5% and then quoted that i would be paying $89 a month for the loan over a five year period. HOW IS IT THIS CHEAP?! I feel like i am being swindled or dragged across the coals here. It seems that the company is called “Slipstream” that the lending is out of. Can i really trust this monthly payment? How can he know that is what it will cost, he didn’t give me any information about how many panels I would need, he told me that this Thursday he will have guys out there taking measurements. I did end up writing him a $500 check for a down payment because next thing I know he was on the phone talking to the lending company.

12:47 UTC


adding panels but no extra converter... good idea?

I currently have 12.5Kw solar panels, a 10kw converter and 2 tesla Power Walls. I easily cover 100% of my current home use, and the system has been working flawlessly for the past 3 years.

Now we are thinking about adding two EV's in the coming years, and I am concerned about being able to generate enough to keep the vehicles charged.

Thing is, the current solar panels *ALL* are on the south side of the home, which means that it takes until at least 10am before I get a significant amount of power from the panels. I do have room for about 4Kw of panels on the east side, which would cover this gap in generation time. Taken the fact that the sun never would fully illuminate both sections of panels.... can I get away with simply adding panels, but not a new converter?

Is the "worst case" that I produce more than the converter can convert (eg loss of generated power), or is the "worst case" a blown converter?

12:30 UTC


Solis Hybrid Inverter 3.6kw trips the Pylontech Battery when charging from grid

I have a Solis Hybrid Inverter 3.6kw and a 4.8kwh Pylontech Battery. I can go months without this issue happening and then for maybe a few days in a row... the DC breaker between the Inverter and the Battery trips while charging from the grid. I cannot figure out what is causing it. Does anyone have any ideas or suggestions for troubleshooting?

08:31 UTC


Mixing B grade panels with A grade in a string

I was wondering if it is a good idea to mix bifacial b grade solar panels with a grade mono facial panels in a string? In my location I can't find A grade panels as they are out of stock but similar sized same brand b grade are available

1 Comment
06:51 UTC


Fronius SYMO Advanced crashing and not working properly

Have a Fronius SYMO Advanced which is 12.5KW and 3 Phase and I'm in need of some help/advice.

The unit since it was installed keeps crashing roughly every week with the same error code (State 415) and it needs to have the emergency shutdown procedure done so that it can come back online.

The Datalogger lost sight of the inverter about 1-2 months after install.

The company that did the entire install include the Tesla PW 2, is saying that they can't do anything as they can't log in.

It also has a few times made a horrible, loud squealing sound which needed to be shutdown and rebooted to stop the noise.

Any advice, guidance, links, anything would be great appreciated.

Thank you

1 Comment
05:37 UTC


No consumption data

We just completed our solar install last month and I’ve been very interested to review the production data.

However, when I wanted to see the consumption data, they said that that is not available for my project.

I have always assumed that the consumption data comes with the inverter. So a couple of questions, 1. how important is it to have consumption data and 2. how common is it to not have consumption data included as part of a solar installation?

05:05 UTC


What guarantees are there for maintenance if company goes bankrupt

I am considering switching from PG&E in CA. A neighbor of mine works for a solar company that is currently going through bankruptcy. She warned me that she has heard about their customers getting left hanging without service and maintenance for the systems they purchased. Anyone else hear about this?

03:26 UTC


California, CPA true-up retail adjustment

SoCal, SCE on NEM 2.0, PTO August 2022

Hi all, So my friend brought to my attention that his SCE bill for May, there are line items in the Clean Power Alliance section called "ANNUAL NEM RETAIL ADJUSTMENT 2023" and "ANNUAL NSC AND/OR RETAIL ROLLOVER 2023."

He was expecting a $1000+ true-up check from CPA, but with this "adjustment", he only received around $300.

I checked my bill (attached), and I was expecting $460+, but with this adjustment, they zero'd me out and I get nothing.

We're both on NEM 2.0. This is both of our first true-up periods. What are we missing? He called CPA and they couldn't give him an answer. They don't know why and can't answer. There's nothing about this on Google. Does anyone know?

It seems to us like they're literally just deciding to keep the money and not explain why.

02:20 UTC


Preventing squirrel damage with downspout access

We are shortly going to have solar installed on our house and there are many squirrels in the area. I have read many reports of them eating through critter guards causing damage to wiring. We are having an overhanging tree removed which I'm hoping will help minimize access but I know they can easily climb downspouts (I've seen them do so). Any particular recommendations to prevent this or slow it down? Adding bird spikes to downspouts at the base or near the roof? Anything more aesthetically pleasing? I'm sure there is no perfect solution but trying to at least take some reasonable steps to protect our investment.

1 Comment
01:19 UTC


Australia proposing 'sun tax' where solar owners will pay to have their energy sent back to the grid

As the title. Solar owners here in Australia may need to pay energy retailers to have their excess electricity sent back to the grid.

It's not our fault that the infrastructure wasn't ready to accommodate the growth in solar.

Homeowners invest thousands of dollars for a solar system to reduce their electricity bills yet they still find a way to make money off you. We even have a electricity bill relief from the government to help with the cost of living, but that will mean flip all when we end up paying back the amount back to the energy retailers.

Surely no other countries have this so called sun tax?


01:05 UTC


Planning Solar

So I am doing some renovation on my home and want to make sure I can put solar panels on my roof. I will be doing a change to my roof line and changing my roof.

I have a Tesla and 1 ice. Leaning Towards at least 1 battery or more. 2 AC units

In June-August I use about 4700kw of energy last year. Jan about 1200

This is Houston TX area.

23:47 UTC


Advice? - 12kwh system

I am looking into getting a solar system/kit which would be able to supply about 12kwh per day. What kind of whattage solar pannels & batteries would you guys get to keep this system running 24/7 (12kwh over a 24h time period, ~500w /230v per hour)

23:28 UTC


NEM 3 (NBT--"Net Billing Tariff") - From the California CPUC Site. One of the few straightforward explanations on how things work moving forward

22:31 UTC


Is a this realistic set up?

Hoping to get some opinions from anyone who has done this. I've been reading Reddit and researching for a bit.

  • I would like to Install a small off-grid battery backup system with solar that charges batteries for my home.
  • Add a some sort of switch to my panel to alternate from grid to battery power. Any major limitations to these types of switches?
  • I don't want to be grid-independent. I want the flexibility to switch during peak hours or whenever I want. Thinking portable batteries ecoflow style and I want to be able to feed certain circuits during a power outage.

I don't want the power company or the HOA involved. I am still looking at if I need to get permits for any of this. I don't think I do but still TBD for Santa Clara County in California. Of course, I will have someone qualified to do all of the electrical work to code.

Has anyone done this?

22:22 UTC


Under NEM3, are September "Power Hours" still a thing? PG&E customer.

I see on the Net Compensation spreadsheet that there are hours in September from 6-8pm that have export compensation in excess of $3.00 per kwh.

Due to PG&E seemingly having finalized their NEM3 rate schedule and put it into effect, is this still a reality when exporting during those times, or has/will that supercharged (heh!) compensation end, and an home exporter cannot realize it?

1 Comment
21:39 UTC


Does Medical Baseline program even do anything for me with PG&E and solar+battery? Anyone have it under solar?

INFO: NEM3, current 13kwh/year user, 10.1kw array, 2x Tesla Powerwall 3 @ 27kw, 130% provisioned, PGE NorCal customer.

I got accepted for the Medical Baseline enhancement from PG&E. I'm also finalizing my solar and battery implementation.

In my brain, the tiered tariff plan that I can have now before PTO (E-1) and can still use post-PTO (E-TOU-C) will only benefit in months that I'm a net importer of electricity. Why? Because, my tier's daily kwh allocation is increased by 50%, making it harder to use my way out of Tier 1, and higher per-kw rates. Hooray, right?

Then again, at least in the sunny months, does this even mean anything anymore? If I barely hit tier 1 when non-solar (towards the end of my month), I definitely won't with self-consuming most of my electricity--at least during spring/summer/fall, right? Only in winter might it help, a bit.

Non-tiered tariffs (E-ELEC, EV2-A) and Medical Baseline will only give me a 12% discount off of per-kw/per gas therm rates for consumption. Same issue, though: During spring and fall, this'll give me nothing. During max summer consumption, a few hours every couple days of pulling from the grid get 5 cents less per kw. During winter is the only time I can see saving money (around maybe $12-25 on electricity).

And the real kicker: does PGE Medical Baseline affect how much the compensation is for any export of electricity I make?

1 Comment
21:30 UTC


Max discharge current.

Hey everyone, help out a noob here. have four 12V tall tubular lead-acid batteries connected in series for a total voltage of 48V. Each battery has a capacity of 230 (Ah). My question is what should be my safe maximum discharge current? Currently, my system is set to a maximum discharge of around 40 amps (approximately 0.2C). However, it shuts down during cloudy weather or when I use the water pump. I'm wondering if I should increase the maximum discharge current to 0.5C, which would be around 115 amps. But I'm worried it might damage the batteries, especially since the average temperature here is around 40°c.

20:19 UTC


How to optimize a smaller system?

I plan on getting solar (and replacing our roof) later this year or next year after we clear up our finances.

So far, I'm planning on getting a smaller system to maximize our ROI based on tax credits. I'm aiming for the solar cost (everything minus the roof replacement costs since that doesn't qualify for the tax credit) to be around $20-$25k (before credits).

What can we do to make this work as best as possible?


  1. We live in Long Island, NY
  2. We just renovated last summer so had new insulation and heat pumps installed
  3. Roof should be replaced within the next few years (likely needs replacement deck)
  4. Rectangle shaped house, south side is short side with brick chimney, back/east of house has trees we want to keep and will block sun, front/west side is the long side with best exposure in afternoon
  5. PSEG offers TOU but we're not forced to use yet
  6. We work from home so will be using power all day
  7. Only lived I house since Sept and bill has been lowest as $150 in Oct to $450 in Feb

Attached a picture of house from Project Sunroof.

19:49 UTC


Bid comparrison

I'm starting to get bids on a PV install, and am hoping to get some feedback here. There's a lot of brands I'm not familiar with, especially with storage.

I'm currently using around 8,000 kWh/year, with full net metering. Any excess production is wiped out in the spring. Connect fee is about $150/year.

My usage isn't that high, and my total bill for the year is less than $1,000. I know this will make my payoff take longer. I don't have an EV, but assume I will within the next 4-5 years. My house is all electric except the stove, so there's no way to shift energy from gas to electric.

I have zero shading on my roof, at any time of year.

The company: small, local outfit. I'll have to check what that means for a warranty, as I have no idea how many more years they'll be in business. There's no way the owner will still be working in 25 years.

The three bids are cash, before any incentives.

If I don't put in storage now, I probably will at some point later. Whatever happens now, I'd like to be able to add storage with minimal fuss later.

Bid 1

PV only, $24,104

5,200 kW, 8,405 kWh per year 112% of current useage

13 x Q CELLS 400 Watt Panels (Q.PEAK DUO BLK ML-G10+ 400)

13 x IQ8PLUS-72-2-US (Enphase Energy Inc.)

Bid 2

With battery, $44,112.00


5.6 kW, 8,928 kWh per year, 119% of current use

14 x 400 Watt Panels (Q.PEAK DUO BLK ML-G10+ 400)

Inverter: EG4 Electronics - 1 x EG4 18KPV-12LV

12 kW Total Inverter Rating

Battery: 1 x EG4 WallMount Indoor 280Ah

14.336 kWh Total Battery Storage

Bid 3

With "better battery system" $52,216

5.6 kW, 8,928 kWh per year, 119% of current use

14 x Q CELLS 400 Watt Panels (Q.PEAK DUO BLK ML-G10+ 400)
1 x 15K-2P-N (Sol-Ark)
1 x Stack'd 19.2 kWh (HomeGrid)

19:34 UTC


Advice: Comparing solar quotes and panels

Afternoon folks,

So I have been thinking of going solar and have narrowed down my searches to two quotes that look pretty enticing.

I live in Massachusetts and I'm looking to get my roof replaced as well. What is the overall comparison of the Qtron panels compared to the REC panels? EnergySage has very positive reviews on both. I want to account for degradation.

What do you guys think? Should I jump all over one of them? Or should I keep shopping?

Viridis Energy Solutions 28 425W Qtron panels 12,860 kWh 117%

IQ8Plus inverters


Roof $8945

$50595 total

Palmetto Solar 27 420W REC panels 11,340 kWh 104%

IQ8 inverters


$9100 roof

$44,810 total

18:56 UTC


PGE NEM 3 - No More NEM 2 - Only Option E-ELEC

I just got off the phone with PGE, I logged onto my account and saw that my rate was changed to "E-ELEC" I was previously on EV2-A. Basically what I was told was that NEM 2 has officially been closed (previously NEM 3 people were still getting NEM 2 stuff) and that this is the only new solar plan for PGE, aka, anyone after NEM 2 will have to be on this plan.

TLDR; I think you'll eventually not have the choice and will be moved to E-ELEC

17:01 UTC


I asked for bids on a section of roof with a steep pitch and was turned down. "too steep".

Was that a code problem or an appetite for working on such pitches issue? It was always hard (CA) to tell what was an engineering issue and what was an economics/sales efficiency issue. if it was a "this is harder than the other jobs we can grab" issue maybe I should circle back?
EDIT: it is 45 Degree slope

16:33 UTC


Can someone help me find out how to troubleshoot a Solaredge “isolation fault”. Years ago I remember using my clamp meter to be able to test my strings to ground and see a leaking number or the number of volts to the point where there is a fault?

Any help is appreciated. I know you can buy a resistance meter. Some are 1-2k. But I remember using a regular meter to trace this out years ago. Or at least I think I do.

1 Comment
15:42 UTC


Solar electrician difficulty

What is is it like being a solar electrician? How complicated is the job? I know for regular commercial and industrial you have to memorize over a hundred wiring diagrams, but what about for solar? Wondering because a solar company just got back to be and not sure if I'll be able to handle the job if its like commercial and industrial.

15:42 UTC


If I do half the panels now and add 25 panels later, will it reduce the total cost ?

We are quoted about $62780 for 50 panel system with 4 batteries for a 21.5kw system. I was wondering if we started with half the size (25 panels) and 1 battery now and expand to add another 25 panels in 3-4 years, would the total cost be lower ? Since we are doing microinverters, I assume that we dont have to size up the non-panel items later. If anyone has experience doing addons, please advise. We are in MA if that helps. Thanks.

13:28 UTC


1st bill after solar installation - Duke Energy Progress, NC

I have received 1st bill after solar and it seems minimum approx. $30. I just want to know why they are charging this much even after positive net metering. Can someone confirm if they are in NC?


13:26 UTC

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