If you choose to rinse them, do it when it's dark or at least cloudy. The shock of a big stream of cold water on hot panels can and does cause microfractures. Even a heavy rain doesn't put the kind of mass of water that is easy to accidently do with a hose. Never use a rag/shammy/etc.
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Residential solar people?
- Thread starter larboc
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If you choose to rinse them, do it when it's dark or at least cloudy. The shock of a big stream of cold water on hot panels can and does cause microfractures. Even a heavy rain doesn't put the kind of mass of water that is easy to accidently do with a hose. Never use a rag/shammy/etc.
Sandy Johnson
Harry Member
Good to know. If it ever happens, I'll do it at night.
arse_sidewards
Red Skull Member
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Why not just use compressed air?
SomeGuyFromOlympia
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They are starting to advertise the Tesla roofs here locally
looked into it, the online calculator penciled out to a 19 year payoff for my house
unless I am doing it wrong, I don't see how that pays out other than the good green feelings
looked into it, the online calculator penciled out to a 19 year payoff for my house
unless I am doing it wrong, I don't see how that pays out other than the good green feelings
Sandy Johnson
Harry Member
I think the Tesla roof only makes sense if your roof also needs replacing.
AKnate
Icehole
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That would be almost an $800 bill here. My power bill at the new place has been about $100, but I think much of that from running a dehumidifier and a 75w light I left on 24/7.haha
I have the lowest usage of anyone I know.
Our wreckless friends who moved into their 2300 sq ft McMansion run the AC at 68 and last month used over 3800 kwh
$565 bill...
We'll see this coming month, I changed that light to an LED on a timer and no more dehumidifier.
75w light doesn't seem like much, but it alone works out to about $11 of power in a month.
Got my Aug. bill from my utility, I've got 3600kWh of banked usage now. I'm going to be WAY over my consumption so I need to find something to do with the power. May be starting a thread on a water source heat pump, or an EV, or ????...
Provience
Kill!
sell it to your neighbors? offer free battery testing and charging?
AKnate
Icehole
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I put in a window A/C and ran that in the summer. Poco only paid 0.05 a KwHr for excess, so may as well just use it instead.
CarterKraft
Red Skull Member
Yeah seems like an excellent way to cool/heat a workshop.
CarterKraft
Red Skull Member
Mining crypto?
AKnate
Icehole
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Is that still even a thing?
kf4zht
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If your power cost is effectively zero it still pays.
Alternative light for growing "vegetables"
Sandy Johnson
Harry Member
Getting harder every day.
CarterKraft
Red Skull Member
Here's everything I know about mining cryptocurrency:
Wheelerfreak
Stunningly Average
We are looking hard at it for just that reason. We need to replace our metal roof and want to do solar too. Problem is there are no installers in our area of BFE and the wait time is a long while. I'd actually prefer ground mount since we have the acreage to do it, but the wife wants a solar roof so... We get plenty of snow in the winter and for my old ass it would be easier to clean ground mount panels.
I'd like a battery backup like the power wall to go along with it. I currently have a whole house back up generator, but it's be nice to have something that doesn't require propane. We lose power a lot, like 2-3 times a month and in the winter it is for days at a time.
Considered the GAF solar shingles? Any roofer that can read can install them.
Wheelerfreak
Stunningly Average
I was recently watching some videos about them, looks interesting. They only have the solar portions for certain areas depending on how big a system you want. The rest is regular asphalt shingles. I'd prefer to avoid asphalt shingles. Plus they don't use micro inverters, instead running multiple "panels" up to a single inverter through a channel. Everything I've read on here when the subject comes up is to make sure you use micro inverters.
kf4zht
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Someone local has some 140w panels and racking that are tempting me for a cheap DIY non-grid system.
The more and more I think about it and loose trust in utilities and our leadership it makes me want to get moving on a backup power and water system just in case.
The more and more I think about it and loose trust in utilities and our leadership it makes me want to get moving on a backup power and water system just in case.
The reason microinverters are popular on roof systems is that they are easy to wire and inherently satisfy RSD requirements that reduce voltage to under 80v when activated. You could use microinverters with the GAF shingles, you'd just need to match them up in strings of 8 or so and probably mount the microinverters in the attic. Microinverters are a more expensive route on larger systems compared to string inverters however. If the system is over 4kW, and not dealing with horrible shading issues, IMHO string inverters are the way to go regardless of panel style. GAF suggests using the solar edge stuff which has a central string inverter, and then roof top modules for every <80V string of PV modules that serves as an RSD and a power optimizer (MPPT and DC-DC converter). I don't know if they integrate the MLPE's into the PV modules or how that works?I was recently watching some videos about them, looks interesting. They only have the solar portions for certain areas depending on how big a system you want. The rest is regular asphalt shingles. I'd prefer to avoid asphalt shingles. Plus they don't use micro inverters, instead running multiple "panels" up to a single inverter through a channel. Everything I've read on here when the subject comes up is to make sure you use micro inverters.
I think the apsystems RSD would fit under the wire cover for the GAF units, then you could wire up a LOT of the solar modules in series and run to a single string inverter equipped with either an integral or stand alone RSD transmitter. Cheaper than optimizers, but you'd leave a little power on the table especially if you've got shading issues.
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tsm1mt
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I'm at 10kwh banked right now.
I heat the shop with an electric boiler and radiant in the winter which I use to eat up the surplus - no, I don't need the shop at 70, but if I have too big of a surplus in February and March..
Last year I did. But this year, I have an EV eating into the surplus, so we'll see.
I still need to add a strip heater into the ductwork in the house so I can siphon off more electricity there.
Yes, I oversized the array, but I knew I could find a way to use it.
tsm1mt
Well-known member
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With my three string inverters, I have three 120V outlets that work when the sun is shining and the power is out. SMA calls it their Secure Power Socket.
That's hard to do with micro-inverters.
On my 2nd and 3rd arrays I had to go with automatic disconnects on each panel to be compliant - my first array got in under NEC2017 and has a whole-array disconnect rather than one per panel.
As to the Tesla shingles - I think it only makes sense if you need to replace your roof AND you were planning on replacing it with some expensive tile in the first place - it's not cost competitive with asphalt or steel.
brantb
1003
Is your power company paying you out for all the excess? If so, what price are they paying? Monthly or yearly? Is there a cap of how much they will pay out to you?
It will be interesting to see what happens over winter. I think you had it last winter, but dont want to scroll back. Have you added anything new that uses electricity to offset your over production? A while back you were talking about and electric car.
It will be interesting to see what happens over winter. I think you had it last winter, but dont want to scroll back. Have you added anything new that uses electricity to offset your over production? A while back you were talking about and electric car.
They will pay me if I leave the utility/move to a house in a different area, however only at the wholesale rate which is $0.08 right now. As long as I'm a customer, I just keep earning credits, they don't expire. I've added nothing since going online about 11 months ago.
DATA!
Sep03-Oct30
Delivered from utility 356 kWh
Exported to utility 308 kWh
Resulting net utility -48 kWh
Inverter generation 398 kWh
HPWH 79.8 kWh
This will be the first month that I'll be starting to dip into my credits a little bit, as expected. The HPHW usage will start dropping as I'm getting into heating season. I'll still have close to 4000kwh excess going into november and I'm averaging ~415kwh a month in household consumption (inverter and utility total). I should be net positive again by the time I get my April bill so I should have extra 2000kwh a year based on historical consumption. I'm predicating I'll have zero generation starting in a few weeks until the end of march.
Sep03-Oct30
Delivered from utility 356 kWh
Exported to utility 308 kWh
Resulting net utility -48 kWh
Inverter generation 398 kWh
HPWH 79.8 kWh
This will be the first month that I'll be starting to dip into my credits a little bit, as expected. The HPHW usage will start dropping as I'm getting into heating season. I'll still have close to 4000kwh excess going into november and I'm averaging ~415kwh a month in household consumption (inverter and utility total). I should be net positive again by the time I get my April bill so I should have extra 2000kwh a year based on historical consumption. I'm predicating I'll have zero generation starting in a few weeks until the end of march.
kf4zht
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Started down my solar plan with some free batteries from work.
These were a miss on the design and couldnt be returned after install. 20x9ah per chassis. I have 24 chassis, gave the rest to my dad for helping me pick them up.
I'm not going for a grid tie - just for my own stuff and I want backup power. Right now looking at a 6000w split phase aims inverter/charger, 80a charge controller and 8 ~300 w panels. Wire the output to a new panel in the house, I already need to replace a ton of wiring since its old and un-grounded. Based off my last power bill, without AC my run rate is a little over 1kw per hour (950kwh in a month)
Trying to keep this all out of the permitting requirements
These were a miss on the design and couldnt be returned after install. 20x9ah per chassis. I have 24 chassis, gave the rest to my dad for helping me pick them up.
I'm not going for a grid tie - just for my own stuff and I want backup power. Right now looking at a 6000w split phase aims inverter/charger, 80a charge controller and 8 ~300 w panels. Wire the output to a new panel in the house, I already need to replace a ton of wiring since its old and un-grounded. Based off my last power bill, without AC my run rate is a little over 1kw per hour (950kwh in a month)
Trying to keep this all out of the permitting requirements
brantb
1003
That is a great deal. Give you time to build up a large number of credits, then if you want you can really balance your system vs use over multiple years.
MChat
Resident "Preacher Man"
Putting together a plan for my off-grid property.
I rented a house in Phoenix that had a solar hot water heater, even during the winter the water came out so hot it could warp plastic bottles. So I am thinking on using a solar hot water system, with a propane based tankless water heater as a backup, just in case.
But the way the hot water systems work, got me to thinking. The systems I am looking at have a liquid (similar to antifreeze) that gets pumped up to the roof where the mirror/reflector unit heats it up, the hot liquid then comes down and runs through a heat exchanger that heats the water which you use.
What I am thinking is that instead of a liquid-to-liquid heat exchanger, why couldn't a liquid-to-air heat exchanger be used by an HVAC system. Even if it is only to "prewarm" the air so a propane-based heater doesn't require as much propane to heat the home.
My google-fu has failed, does such a system exist? If not, I could probably piece together a system from water heater parts; if I can figure out it is even worth it.
I rented a house in Phoenix that had a solar hot water heater, even during the winter the water came out so hot it could warp plastic bottles. So I am thinking on using a solar hot water system, with a propane based tankless water heater as a backup, just in case.
But the way the hot water systems work, got me to thinking. The systems I am looking at have a liquid (similar to antifreeze) that gets pumped up to the roof where the mirror/reflector unit heats it up, the hot liquid then comes down and runs through a heat exchanger that heats the water which you use.
What I am thinking is that instead of a liquid-to-liquid heat exchanger, why couldn't a liquid-to-air heat exchanger be used by an HVAC system. Even if it is only to "prewarm" the air so a propane-based heater doesn't require as much propane to heat the home.
My google-fu has failed, does such a system exist? If not, I could probably piece together a system from water heater parts; if I can figure out it is even worth it.