openinverter forum

do NOT recommend !

That's a lot of sand, way more than here

Dusty panels isn't much of a problem here, more like mossy panels.

We were buying 10 yr old panels from the only Aust solar panel manufacturer, Tindo, and cleaning them for reuse.
We bought 2 brush floor polisher on Farcebook market place, sprayed kero on the panels and did them over with the floor polisher, then truck wash to clean the kero residue. Then polished them with cut and polish car polish, then the last coat with premium quality car polish.

The output returned to the factory specs, leaned up against the fence facing the sun, no lightbox nonsense, real world testing.
The dull white look on the panels was gone and the clear blue of the light the panel couldn't use returned.
The two coats of polish meant the dirty dust filled rain simply ran off and the rain or a hose cleaned the panels for the next 12 mths min.
A wash with truck wash in the water and and another quick coat of polish, and the panels were good for at least 2 yrs with just a hose off.
My house burnt down so that was the end of those panels, but the mate has the roof of his houseboat covered in these panels and he lives on full 240vac power, fully off grid and has done so for the last 5 yrs.
The care people who look after his needs as he is legally blind and on an aged pension, paid for a solar panel cleaning company to clean his solar, they came back down off the roof and said someone had clearly been there before them, the panels were clean .... they contacted their office and cancelled the job ....

T1 Terry

I'm learning solar panels don't like the heat, they like the sun light but not the heat if that makes any sense, and a quick GOOGLElization suggests: " Solar panels perform best in moderate temperatures, typically around 77°F (25°C)." and not temps North of 100°F like we get here in July\August

So my ten 200 watt solar panels aint producting 10 kWh of evergy daily as I have hoped. (goal was set based on my human trait of liking round numbers and feelings)

So I will be adding two more 200 watt panels. But wait you exclaim as you sit up in your chair and set your luke warm beer down to take to the keyboard: "didn't you say you had a perfect 2,000 watts worth of solar panels feeding into your 2,000 wat grid tie inverter? how do you expect 2,400 watts of solar panels to fit into that handsome blue box now?"

Well this is where we reap the rewards of hands on training, you see there's book learnin' and then there's a doin'. So what I have learned is that solar panels at best are 70% efficient (not to be confused with solar cell efficiency of 23% or less)

Fun Fact: Solar panels in the Solar Panel Factory aka the SPF are not tested using the sun as an energy source, no sirree Bob. They are laid perfectly flat under a sun stimulator (Xenon arc lamps and or metal halide lamps) no wind, no clouds, no dust, and in that perfect setting they may come close to say 200 watts for a millisecond like these 200 watt panels in my case, but most likely its like 187.6 watts that then the Marketing Department (pronounced: liars) round up to 200


I really like the high voltage that these panels operate at, and I sometimes wonder if they are marketed as 24 volt panels instead of 36 volt just so dummies like me will come across them doing our silly 24 v solar panel Google searches

Panels are tested at STC (standard test conditions) as stated on the label.

In the real world this is hard to do. If you have a 1000W/m³ of sunlight the cell temp will rise quickly and for every degree Celsius the pannel will lose some max power.

Here are some specs from a random panel.

Temperature Coefficient of PMAX -0.36%/°C
Temperature Coefficient of Voc -0.26%/°C
Temperature Coefficient of Isc 0.04%/°C

With higher temperatures the current goes up but the voltage goes down faster. So the power goes down with 0.36%/°C

So if a panel is 70°C cell temp: 70-25 = 45 × 0.36 = 16.2%

Than the 200W panel will produce 167.6W

The Dirty Dozen

2,400 watts of solar panels ==> 2,000 watt inverter
(in other words 80% efficiency)

System Cost:

12 panels at $173 each = $2,076
1 inverter at $176
cables & misc approximately $100
TOTAL COST: $2,350


oh man, so close to 10 kWh, I am certain it's the August heat keeping these panels from producing more energy

and here's why we do it:

and here we are selling energy back to the City



SMUD buys back excess solar energy from new customers at a flat rate of 7.4 cents per kilowatt-hour (kWh) under its Solar and Storage Rate (SSR), which took effect on March 1, 2022. Existing solar customers on the older Net Energy Metering (NEM 1.0) rate will continue to receive approximately 13 cents per kWh through 2030 before transitioning to the new SSR rate.

Well they don't make this part easy, but that day all that 7.8 kWh of energy that I sold back earned me $1.17 but none of that really adds up when I dump the data into Excel and attempt to crunch it, oh well, Electric Company Math I guess, ECM !

Woo Hoo! only another 2341 years until you've made a $million

Alibro wrote: ↑Mon Aug 25, 2025 6:37 pm Woo Hoo! only another 2341 years until you've made a $million

So it's actually that easy? Just whack the panels on your roof and have some random inverter convert it to AC. No need to ask for permission, no need for a "certified Electrician" to "commission" your system?

Your grid must explode into a gigantic fireball and then become a black hole. At least that's what they say in Germanland

johu wrote: ↑Tue Aug 26, 2025 5:31 pm So it's actually that easy? Just whack the panels on your roof and have some random inverter convert it to AC. No need to ask for permission, no need for a "certified Electrician" to "commission" your system?

Your grid must explode into a gigantic fireball and then become a black hole. At least that's what they say in Germanland

I mean...

E for error, wrong gender connector for power out?

jrbe wrote: ↑Wed Aug 27, 2025 1:27 am E for error, wrong gender connector for power out?

please explain in forklift terms

User manual says somethin, somethin,
Look for electricity bite at danger hole E.

Ranks as perfectly balanced 50/50 in forklift terms, convenience / safety split

It never outputs voltage. It just feeds current into an existing voltage and shuts down when that voltage goes away. So when unplugged it's never live.

I just love days like this:

(did I mention I have three electric vehicles)

Rather like these, too
Meanwhile we've whacked so much PV on various roofs that even the 11 kW Seres charger can't max it out. The graph only contains the power delivered by the SMA system and doesn't show the extra 7 kW from other systems when directly consumed.