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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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126,125 Subscribers


3 phase inverter - any which auto balance or do they all split power equally?

I have 3 phase power to my home and I’m not 100% sure what lights/appliances/etc was put on each phase.

I’m looking into a small solar PV system (<6kw) and have found that 3 phase inverters seem to split power equally between the phases.

Are there any 3 phase inverters out there which can send power generated to the phase that is demanding the most load at the time or do they all split evenly, meaning that I might always be sending unused power back into the grid if a phase is underutilised?

05:42 UTC


Solar DC bypass during grid outages?

I’m wondering if there’s any reasonable (and ideally still to code) way to manually redirect the DC output of at least one of my strings (normally attached to a SolarEdge 7600).

I know that in a grid outage my utility (pg&e here in CA) will remotely disable my inverter.

I’m not really willing to invest in a large battery and additional inverter right now both because I feel the tech will improve rapidly and because I generally believe that v2x / v2g / v2h is a more efficient use of resources long run.

The shortest cheapest path I can think of to making some use of my 7.2kw of panels to struggle through a grid outage is to charge a very large power station or set of power stations directly from the panels since they typically have solar inputs already, mppt charge controllers and smallish inverters.

I could imagine breaking out incoming string wires from the edge of the solar edge inverter and using a physical switch to manually move them to a different circuit during a grid outage and connecting that circuit directly to the solar input of said large power station.

Is there a proper way to do this? Is there a similarly inexpensive low investment approach?

Odds are low since I have not yet had more than 6 hours or so of outage in any pg&e PSPS outage thus far, but I’ve had nearby friends in suburb cities that had 4-5 day outages iirc. In that situation it would be nice to get some power from my panels to charge…

04:51 UTC


Probably a dumb question

Does the solar pannel still generate electricity if the inverter is showing an error code? We have a goodwe inverter and i occassionally check the app to see them sweet sweet power generation numbers up but on opening today noticed that there are no generation details for the last 4 days. I reset the inverter which fixed it. So question is, is it just a matter of connection error and the pannels were still generating electricity and just not communicating the numbers or were they not generating anything at all?

00:22 UTC


Solar Loan or PPA

So I’ve been exploring anew system for my new home. I have 2 options

-0.10 kWh with a .99% increase for 25 years with a buyout options starting at year 5. $203 a month. For perspective electricity is 0.17 kWh currently

-or a 9.5% loan for 25 years. $260 to start and then over $300 after 18 months if you don’t give them your tax credit.

The PPA has no lien clause and seems pretty good the only down side is you technically don’t own the system if you never buy it out, but my goal is have a constant lower electric bill.

Is a PPA actually bad?

23:25 UTC


Best way to wire up for 1000w output

I just bought an ecoflow delta 2 max and it has 2 charge controllers and inputs for 500w each. It can handle 11-60v input.

Two 400w panels would be simple enough to attach but there are a ton of used 250 watt panel for around $80 each where I live. Would it be possible to use 2 250 watt panels for each solar input? And how would I got about wiring that?

1 Comment
22:36 UTC


Illinois pricing question.

Im currently just trying to find a rough estimate for a 10.5kW ground mount system near central illinois. Im no where near ready to proceed forward. I will be in about a year since i get some money from when my father died as a child. It was put in a fund and i receive it when i turn 30. But enough of that. Ive called like 5-6 different local solar companies throughout illinois and literally not a single company would even give me the time of day or even entertain the thought of giving me a rough price??!!? I dont understand why theyre being so secretive about it. I see the avg price per watt online. But i just want something a little closer then that. This Makes me not want to hire any one of those companies next year with them being so secretive. Seems sketchy to me. I want to pay cash for the system. But all those companies keep trying to make me go through the whole bid process just for a estimated price and some keep saying “well we can also look into financing options, so you can go solar quicker.” One even said i needed to pay the $150 fee of them putting a bid together before they would even give me a price. No. I really dont want to do any of that. I have a plan that i want to stick to and all i need is a rough price. Has anyone on here gotten a ground mount system near that size bidded, completed or has anyone bid out a job that size? Sorry if i seem a little ticked off, the last guy that i talked to really pissed me off. He was talking to me like i was stupid and kept saying passive aggressive shit. Im an engineer by trade so i took my last two years of power avg’d them instead of just using 1 year. Sized the system. Then ran it on this site to give me a projected production for my area. And 10.48kW was the size needed. I rounded up to 10.5. Anything even remotely close would help. Just any ground mount system would work. I can do the math in order to figure out what mine would cost. THANK YOU IN ADVANCE SOLAR COMMUNITY.

22:04 UTC


Anyway to remove home lein?

I have a loan through sunlight financial. Is there anyway to remove their home lein on my account?

20:37 UTC


Commission structures?

For those of you working on commission, what type of structures do you have? For those working on a commission per Watt, what are you experiencing? Differences between lead generators and closers?

20:17 UTC


I need a new roof but want to keep my panels. How do?

I bought this house (new jersey) with solar panels a few years back. I was in negotiations with the solar company over the contract terms. Terms were never reached, I never signed any contract, then the solar company got bought out by a bigger one. That was over 2 years ago now. No word since. SRECs get dropped into my account yearly. No electric bill over 8 dollars since I've owned the place.

Are these panels legally mine now? If so, should I just try to find a roofer that is willing to move the panels? Or what? I need a new roof pretty soon.

Thanks in advance

19:18 UTC


idea for an incentive to help people adopt solar

hey there, just want to know if this is a bad idea.

so i've been thinking of a way to differentiate myself from all the solar sales people in my market and there is quite a bit of money in the sale typically in the thousands.

my idea was is simple i think. i would want to take the commission i earn and allocate it into an investing account currently vanguard rate of return for one of their accounts is 5.3%

the average commission is 12,500 over the course of 5 years if things go smoothly then the interest earned would be $3700


something else i was thinking was creating an extended warranty that covers 90% of the cost to have the panels removed if roof work needs to be done. the cost is about 170$ per panel and from the deals ive done even if they needed work done on the roof id still be in the green if i did this. but then if the roofers do a poor job and the panels need to come down again sooner than i would hope it could definitely affect me negatively.

i just want to find a way to reduce the risk for the home owner and that panel cost is an objection that has stopped a few deals for me and i dont want to be a shady sales person thats like oh yea its only a couple hundred bucks when its really a few thousand depending on the size of the system of course.

17:44 UTC


Micro-inverter Sizing DS3 vs DS3-L


I have a quote for a 8kW roof mount grid-tie system in Canada (BC). Cost will be approximately $15,000 CAD after rebates on a 0% 10/year loan.

  • 16 - 500w LONGi panels - 8000w
  • 8 - AP Systems DS3-L micro-inverters - 6144w

My question - why not use DS3 inverters for the slightly less clipping at maximum load (7040w)? Based on the data sheets I would get around 900w extra AC at max output.

  • Is the extra cost not worth it for the minimum increase in production? It could also be the maximum string length is problematic?
  • Is the large DC/AC delta to accommodate the panel degradation over time, whereas AC output will remain constant over the lifetime?

I will inquire with the installer on Monday but I thought I would ask the community. - Cheers

17:27 UTC


Heat pump and solar

My husband and I live in the northeast US in an older home. We have a newish gas boiler/ water heater (radiators) and have decided to add solar panels. We have a company chosen and paperwork started. We also want to install some kind of air conditioning (I am so done with putting window units in) and realized this decision may impact the solar panel design.

Would it make sense to install a heat pump for a hybrid heating system? From what I understand, the heat pump would operate up to a certain point (around 45-50 degrees Fahrenheit) and then the boiler would operate below that temperature.

If I do this, is there any way to estimate how much additional electricity we’ll use? I’m struggling with whether or not we should change our solar design before it’s installed. It just seems like any estimate is a complete shot in the dark and we could either wildly oversize or undersize.

17:26 UTC


Fox ESS & Tesla Powerwall2 Issues

I’m in the UK using a Tesla Powerwall2 with a Fox ESS H1-3.7-E inverter (3.8kw solar array).

When I choose the “go off grid” option on the Tesla app, the inverter waits for 1 minute, goes through its normal startup process and then starts feeding energy as normal (this registers as solar energy input on the Tesla app). But after about 30 seconds, the inverter cuts out with a communication fault between manager and meter. It goes through another one minute long “checking“ process, then starts up again and works for another 30 seconds, before doing the exactly the same thing. This is continuing on an endless cycle. Does anyone have any ideas how to solve this?

1 Comment
16:35 UTC


Opinion on a quote

Location: northern Virginia

Panels: 26 REC405AA Pure Black Series

Inverter: Enphase IQ8 (spec sheet says these top out at 300watts yet my panels are 405watts)

total cost: $31K

System size: 10,530W

annual Production: 10.7kWh

Cost per watt: $2.94

Cash purchase

16:15 UTC


I have a 9.9kw solar array with a goodwe gw8500-ms. Looking at retrofitting a Goodwe GW5000S-BP Inverter which ac couples into my system. If I was to buy my own 50ah 48v batteries do i need a charge controller or is the goodwe SBP going to handle it?

Going for Lifepo4 cells. Just wondering if the inverter will work without coms to the batteries or is that just for battery banks.

16:10 UTC


Lien on house

So I recently cancelled a contract with sunlight solar after 12 days the law in Florida say's I only have 3 days any ways I cancelled because my mom and I don't qualify for the tax credit we don't have enough tax liability. So when I called the receptionist said I must pay 5000 because I cancelled after 3 days. I terminated the contract any ways. All they did was a site survey nothing more before I cancelled. I terminated the loan agreement right away thank god because they kept sending me emails and engineering plans after I cancelled they were even tried pulling the permit after the fact but i called city hall where I live and blocked it. They also tried to reinstate the loan I had cancelled. Now they're sending me certified letters telling me if I don't pay the 5000 dollars they will put a lien on my house for what a site survey. My mom has Alzheimer and I'm on SSDI we both have limited income this lien will put us in bankruptcy. Is this company really able to do this? We would of never been able to afford the panels without the tax credit.

16:09 UTC


8+ years of data logging for my 3kw solar array in N. Utah - AMA

15:25 UTC


Any idea why my panels aren’t showing up or producing?

I’ve got the solar contractor coming out next week to take a look, but I was wondering if anyone could tell me why this is happening.

There should be another 15 panels in the red box on the north slope of my roof. However, they are not showing up at all. Only 1 of the 16 on the north slope is appearing in the app.

The 14 on the southern slope are all showing up, but only about half of them are producing any energy. None of these panels experience any significant shading; in fact the only ones that see some shade for part of the day from a nearby tree are the ones that are producing just fine (3, 6 and 2).

Lastly, panel number 9 seems to be doing significantly worse than it’s two neighbors (5 and 6).

Any insight is much appreciated. Thanks in advance!

14:34 UTC


What company should I go for in Minneapolis minnesota area

Looking for solar panels

14:07 UTC


No net metering - still worth investing?

Here is my electric company solar guidelines : https://farmerselectric.coop/solar-power/

I have no other alternative available at my location. They buy back at their cost which likely means I wouldn't get back much right?

Does it make sense for me to invest in solar or should I wait until the next home I own? Probably 4 years minimum before I would move but could stay longer.

13:02 UTC


need advice on rv solar setup

Hi everyone. We are moving to a 4 acre piece of land that has water and septic. We live in a 34ft motorhome. I have 2 new lithium 100ah 12v batteries I want to use for solar till We can afford to get electric connected.

My question is about my setup. I was going to stay at 12v by wiring the batteries in parallel. I am looking at six 12v 100w solar panels, 60a mppt controller, and a 2000w pure sine 12 to 120v inverter.

As I continue to research, I see a lot of recommendations to use 24v instead of 12v. Does anyone know enough to chime in? Will my setup work with decent efficiency? Any suggestions or comments? Thank you in advance!

12:52 UTC


DIY off grid setups.

What is the cheapest brand to go with that’ll have a product that actually works.

Renogy seems pretty competitive, and the kits seem simplified down to the basics you’ll need.

I’m using this for shop lights and door openers Should use around 1.6kw per day. With unlimited storage how many solar panels would I need?

Do I need a set charge controller?

Do I need a certain watt inverter?

Not worried about storage got about 35 golf cart battery’s I’m gonna tie together.

12:39 UTC


Solar Panels Mounted Flat on a Flat Roof but Azimuth is 176 Degrees

I have a flat roof and just recently got solar panels installed in the Bay Area. They are mounted flat, but my design says the roof pitch is 2 degrees and the Azimuth is 176 degrees. Should my installer have installed it at a tilt/angle so that it would be facing South (Azimuth 176 degrees)?

I was curious about how the solar panels can be facing South if they are laid flat.

Thanks in advance.

06:44 UTC


Fronius Primo System - No Data Available on Solar Web

Having some trouble with Fronius Solar.Web and my system. Fronius Primo.

Live usage data is visible, however logged/historical data (Seen in "Energy Balance") ceased Feb 2022.

The energy balance window shows my inverter grayed out "n/a".

**Actions Taken:**

Verified Visibility of Components. All Visible. No Change.

Updated Datamanager. Successful. No Change

Redo of Setup Wizard for datamanager. Completed. No Change.A

ttempted to update inverter to latest update. failed.Restarted inverter. No Change

Attempted again to update inverter. successful update.

No change.

Any suggestions to start having Energy Balance graphs available again?

04:46 UTC

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