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 Links

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


142,272 Subscribers


Any reason NOT to use 485wBFD bifacial versus 405w (in this case)?

Consider this situation : In the attached image, you will see a layout of ~400watt 72"x42" modules. Notice the 4 landscape arranged modules. Also note that the entire arrangement is 18" from the ridge. It is possible that the local jurisdiction will require 36" from ridge, in which case the landscape panels will not fit. To better utilize the same left-to-right roof space, I could either do two rows of 5 landscape and fit 10x400watt (4000w) on either side of ridge, OR do a single row of 9 485watt bifacials (4365watt) on either side of ridge. In addition to the increased rated wattage, the installation would consist of only two mounting rails, versus 4, per side.

I was recently made aware that the rating for bifacials is commonly the rating for the front face, so while I know that generally I wont get much, if any, rear side generation on roof mount on shingles, is there any reason NOT to use the 485watt bifacials. Cost per watt is actually pretty much the same with Q.Cells 405 at $234.00 ($0.58/w) and Q.Cells 485 BFD at $258.00 ($0.53/w)


23:04 UTC


Trying to pick an inverter for some EV charging and other misc loads (Dryer)

I have 36 panels at 280 watts each. Picked these up really cheap.

I just got a chevy bolt and I'd love to charge for free. Looking at inverters/ mppt now.

I'd be fine just charging the EV in the day and skip over the batteries. Would something like the Growatt MIN 6000TL-X work just to charge my car at 240v? I know the watts coming out of the panels in the daytime would fluctuate so the grid power would pick up the slack with that unit?

Would I have trouble hooking a dryer up to that unit?

Amazon has these for sale which seem to have that functionality.


Or would it be better to just come up with some cash for an off grid system with batteries and maybe an eg4 or two?


1 Comment
22:03 UTC


Charge EV at lower rate during daytime

I have an option to charge the Tesla at 48A. However during the daytime should I be charging the Tesla at a lower charging rate lets say 24A such that the energy being produced from the panels is going towards the EV and not going to the grid for a longer time. I am on NEM2 with the TOU C plan in CA.

Edit: Post title is for lower charging rate.

21:46 UTC


System not charging with generator.

Hello, Looking for some troubleshooting advice. My system will not charge from our generator. I have it bypassed right now so the genny is providing power to the house but if I run it through the inverter it does not charge the batteries. Sorry been on solar for years but this system is way more complex than I’m used to. Thanks for any help.

18:32 UTC


Advice/Solar Farm Lease

Somewhat new here so apologies if this isn't the right place. I live in a rural area on 300+ acres, less than a mile from a coal power plant. Recently solar farm companies have reached out to us about leasing some of our land for solar panels. We haven't agreed to anything and still have questions. But the problem is the same companies reached out to all of my surrounding neighbors as well, but they are all adamently against it. So far as to going to the county and trying to block all opportunities. Their biggest complaint that I can see is that it's an eye sore... but they keep "finding" information on the internet about how damaging solar farms are to the environment and health. This information is the opposite of what l've read. There is a council meeting in a week so I guess I'm on here trying to get I formation from experts or opinions from people who have similar leases and what their experiences are.

17:46 UTC


Seeking Advice on Solar Setup

I'm diving into the world of solar energy for my home and could use some guidance.

  1. I'm curious about the differences between N-type and P-type solar panels. Are both types typically monocrystalline?

  2. Any recommendations on reliable solar panel brands and models? What about inverters - which ones have you had success with?

  3. Lastly, I'm on the lookout for an affordable lithium iron phosphate battery. Any suggestions on where I can find a good deal?

17:41 UTC



I’ve been in this sub for a little bit now and I never see anyone really mention Tesla panels/solar. What’s the reason?

I have a solar city lease (which is now Tesla) and am looking to get a supplemental system. I figured since I’m already dealing with tesla I might as well give them a shot. So far the “designer” hasn’t provided desirable or accurate results.

I’m wondering if this is part of the reason I never hear about Tesla….

Please tell me your thoughts.

Location: Long Island

17:03 UTC


What is "PE" on a lux inverter solar system

Hi guys

New here, we are currently installing our solar system DIY style. Trying to figure out what "PE" stands for, can't find any answer on the internet. Is it a fancy way of saying "Protective Earth"

Please help ASAP

Solar noobie here

17:00 UTC


Math not quite right on Solaredge consumption metering. What might be wrong?

I installed the system myself and learned a lot about electrical and building codes, permits, and utilities in the process. It was a great experience overall, but these incorrect Consumption numbers are puzzling to me, especially since the same information is presented correctly elsewhere on the page. Anyone else run into this. I have a Solaredge Energy Hub SE 11400 without batteries.

16:42 UTC


When does NEM 3.0 actually start for PG&E (temporary NEM 2 billing)?

I got my PTO in December and it states "Customers that completed their interconnection application after April 14, 2023 will be enrolled in Solar Billing Plan but temporarily billed on Net Energy Metering 2 (NEM2)". How long will I be temporarily billed on NEM 2?

16:41 UTC


Poor Solar ROI - Installer Markup Insanity

I have been in the market for Solar, and I just can't get my head around the ridiculousness of solar installer markups. With respect to panels, inverters, mounts/racking, and install (on a cash basis):

  • Sunnova demands $3/watt (talked down to 2.83 for commodity equipment).
  • Decent-sized Texas company wants $3.50 non-negotiable (std bougie +).
  • A bunch of options land around $2.80 (std bougie +).

They all talk about warranties, blah blah blah, but warranties are as good as the companies that back them. (And there is no bonding / reinsurance / etc. unless you can take advantage of manufacturer warranties, which may / may not include labor.)

You can pick up bougie+ equipment online for ~$2-$2.20/watt (REC Pure + Sol-Ark / Enphase + Iron Ridge + mounts).

On a like for like basis, the equipment I'm considering comes in at $20,000-$25,000. Most companies want $40,000-$55,000 to install and "warranty". I'm assuming that they can generally get better pricing than I can.

What am I getting for the additional $20,000-$35,000? How can I justify it on an ROI basis?

(FYI - I discount the value of warranty, as I have previous experience with a 10 yo commodity string inverter system that never had a single issue.)

16:39 UTC


Price check: $2.63/watt

4.92 kW 12 REC 410w AA panels with Enphase IQ8M microinverters. $12,950 which is $2.63/watt

That's about the best I can find in my area. San Francisco Bay Area from what seems to be a well reviewed company with decent history.

Ok deal? Great deal?

Added an EV, heat pump HVAC and a 1bedroom all electric ADU with a mini split HVAC so I'm heavily considering upping the system size. The price per watt stays the same so I'm guessing this is probably the best my vendor can do.

16:34 UTC


Quotes and panel/company recommendation for Maryland

Working through energysage and have a few quotes, also reached out to Lumina Solar and waiting on a reply. Looking for thoughts on a few companies in MD that I have quotes from. Looking for reputation feedback and panel comments (company / panel / $ per W / % need met / inverter)

Sunshine Saves / Silfab Solar SIL 420 QD Prime NTC / $2.95 / 105% / Enphase Energy IQ8 IQ8M-72-2-US

Cosmo Solaris / REC Group Alpha Pure REC410 AA / $3.61 / 101% / Enphase Energy IQ8 IQ8H-240-72-2-US

Nova Solar / LA Solar Factory LS550BL / $3.39 / 103% / Enphase Energy IQ8 IQ8H-240-72-2-US

Solar energy world / Q CELLS Q.PEAK DUO BLK ML-G10+ 400 / $2.91 / 120% / Enphase Energy IQ8 IQ8PLUS-72-2-US

I've seen negative comments elsewhere for Cosmo Solaris and they've already called 3 times and texted in less than an 18 hour period. So leaning strongly away unless someone has a reason not to.

I've heard good things on REC panels and they have the tightest power degradation warranty, but I am hesitant with the install company or if it's worth the extra cost.

Anyone have thoughts on companies listed or panels?

EDIT: Updated to include inverters.

16:08 UTC


Looking for 475 or larger mono-facial panels

Due to the geometry of my roof, I am trying, with little luck, to source some 475watt or larger mono-facial panels. Hoping to find some in the ~82"x~42" size. I seem many bi-facials in this geometry, but am having a hard time finding any Tier 1 mono-facials. I don't need those exact dimensions, it is just that the more common ~72"x~42" proportion just wont allow as good of coverage (due to fire access requirements).

Anybody have any leads?

Prefer Q.Cell, REC, but possible open to Canadian Solar, or equiv.


13:46 UTC


Different proceeds Inverter and ptimizers

Hi there,

I have a new Solaredge system, got the old one replaced because of age and wanting more panels.

Now I found out that there is always about 400-500watts difference in yiels between the inverter and optimizers. Doesn’t matter if the day has brought 2,5kwh or 7,5kwh, there is always a difference of around 450watts between optimizers and inverter.

Does anyone know what the rootcause of this is?


1 Comment
12:57 UTC


Clarification on billing with NEM3.0 and PPA

I am considering going solar but with PPA and it's going to be under NEM3.0 PGE. Nobody is able to clarify how billing works, is it: A. It's the energy difference of the usage and generation i.e, if I use 1000 units and produce 900 units in a month then I only pay for 100 extra units? B. You accumulate credits per moment i.e, during the day when I generate more I accumulate credits at 8 cents/kW and then I use these accumulated credit to purchase at 40 cents/kW when I am producing less(both rates are examples). Any official links that clarify on this?

11:08 UTC


Panel Check

Most seem even but a couple are a few kWh behind… is that standard? Or something wrong with panels?

07:24 UTC


EV charging strategy

California NEM2.0 here. PGE just increased rates again. There is a reliable EV charger next to my home at a lower per kwh rate than my PGE off-peak rate. Would I be minimizing costs & minimizing my solar payback period if I just always go there to charge my EV, and never charge it at home (so that I maximize net metering credits)? Would that calculation be correct, or is there a factor I'm missing?

04:42 UTC


Ultra mini solar electric cooker prototype! 10-15w

Hi all, sharing this 10-15w mini solar electric cooker prototype I built in my workshop. The performance was shocking to me. Only a 20-watt 12 volt solar panel easily boiled an egg.

My belief is that in the future, the world will need small, portable and efficient solar electric cooking devices. I've developed several. Here is just one - I had to show it.

Power: for sure only 10-15 watts boils an egg or cooks any food - easy. A 20-watt 12 volt solar panel in good sun was more than enough. Even at 6 watts, it can reach boiling point. It takes a while. This amount of power and heat (watt hours) is simply trivial. 

Size: it's small, portable and incredibly efficient for mobile use. One egg will easily fit with room to spare. Obviously it could be larger, but I don't have a metal lathe or ability to machine custom parts at the moment. I am limited to what's at hand. 

Heating element: a solid state diode chain (diode string) matched to the voltage of maximum power of the solar panel. It's not MPPT, but it acts similar. There is much research on and documentation my youtube channel about this topic already.

Robust construction: NO complex electronics, no apps, no bluetooth, no IoT. Plug it in, put the food in, it just works. Yes it might need electronics in some use cases.

FYI I am developing a much larger version. Recent test were very good, rolling boil reached with clearly less than 50 watts, plenty of room for food inside. Still very portable.

Well I hope you liked this! https://www.youtube.com/watch?v=CRhkZp6ECHk

David D. / Solar Power Edge channel.


04:04 UTC


any experiences with/working with skyline?


03:29 UTC


Just landed my first D2D sales job selling solar panels. What should I expect?

I (22M) just landed my first sales job with no experience, I live in a state where the installation of solar panels is footed by the state if the homeowner's roof is in good condition. I will be selling solar panels door to door.

I have a training period that is expected to be 2-8 weeks depending on my performance during it. Since I have no experience they said it will probably be ~4.

To explain a bit about the job, it is 100% commission, about $200 per KW, and I have been told that after I've graduated training, I will be expected to make 6 sales per week month minimum. I've seen higher rates per KW mentioned here, but bear in mind that that is already far more money than I have any idea what to do with.

I've already been warned that the job can be extremely stressful (the guy interviewing me even asked me for my coping mechanisms for when I "inevitably" try to quit lol), but I'm determined to hold this job down for as long as I can.

I'm not overly certain that this is the correct place to ask, but I've seen other posts from salespeople here, and I don't want to karmawhore enough to post in /r/sales.

What should I expect from this job? Is there any tips or general advice someone with more experience in the subfield can offer me? My first day of training isn't for another week and a half, and I can't really contain the excitement.

E: fixed an oopsie of me not know what time is.

E2: It has come to my attention that the overwhelming majority of redditors have a total lack of reading comprehension.

02:55 UTC


Looking for a 200A main panel that will accept Enphase CT's on the mains to the meter +225A backplane

Can anyone recommend a 200A main panel that will accept Enphase CT's on the mains to the meter pan?

Also with a 225A backplane. And likely combined with meter on top.

It's been bloody difficult to find but it must be out there! -Thanks

01:45 UTC


Installer won’t install a consumption meter; how do I know if things are wired correctly?

I’m having my installer come over to check the wirings again on our Enphase because our bill was too high this last month. Import was 872kw = over $300 for electricity alone. When I asked if they can also install a consumption meter, they said they don’t do that because it will interfere with my utility’s meter readings and has inaccuracies. Anyway, is there a way to tell from the wire install if things were connected done correctly, without a consumption meter?

Also, do these numbers on the panels look okay? So far this February, the best day was about a 12kwh production only.

01:41 UTC


EcoFlow ultra SolarEdge question

3.5kw solar array roof mounted going into solar edge inverter which feeds to 30amp breaker in panel. Apparently the solar panels only get power (optimizers) when the solar edge inverter has AC power. If they don’t detect that the inverter has AC power they go into a dcsafe mode and only output 1v.

My question is, I also have a delta pro ultra that has 240v out. If I run the 240v output from the EcoFlow to the 30a generator input of my panel, could I effectively enable the power to the solar edge inverter in order to supplement the power used by the EcoFlow if the solar panel optimizers become active again by powering the solar edge inverter.

00:25 UTC


Need help understanding configuration

We have solar installed, along with a battery and car charger, and an outlet for an outside generator. I am not confident at all that i understand the various disconnects and under what circumstances i would utilize them. The permit set i have does not 100% match the as-built system but I think I have mapped the images to the drawings (making a couple of guesses). Can anyone provide clarity/corrections on which of these switches does what? I intend to post a final version of this diagram near the system for future reference .


1 Comment
23:37 UTC


Metering issue - incorrect consumption CT placement?

Last week my battery finally came on line, and with that the consumption CTs. First it seemed like import and export were reversed, which Enphase fixed via software, but now my system is showing no exports at all (when my PG&E meter does show exports). I'm also getting the "consumption mirrors production" issue, and my battery disharged at full tilt, exporting over 5kW because it thought my house was consuming when it wasn't.

Enphase thinks the consumption CTs are not installed correctly. I'm pretty sure they're only on the lines from the main breaker to my sub panel, so I don't know how they'd ever see export, unless that's supposed to be determined via math. Enphase has also advised leaving my battery in full backup mode until this is fixed.

Enphase informed my installer of the issue (because he doesn't listen to me--but apparently now he doesn't listen to them, either). So I guess I have to either fix it myself if it's easy or hire someone else and add it to my ever-growing CSLB complaint.


21:54 UTC


To install solar panels

Hello everyone,

In canada and USA what license do we need to install solar panels and is it different license for commercial and residential location? And if there is any licensing we need what is the procedure to get the license and what qualifications are required.

Thanks in advance. Any suggestions or help would be appreciated.

21:37 UTC

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