Solar outage saga!

Alternative energy sources
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The usual. As I have two large solar PV systems here, and my lab assistant just put one in, and others are interested in things like this, here's where that stuff goes. This is mostly for things that work now, not "gee someday a fusor will do this" -- we know that, but it's not someday yet.
The hope is to save anyone embarking on this sort of thing a lot of wasted time and money, as at least I have been off the grid since 1980 and have had a lot of practice (and made mistakes you won't have to).

Solar outage saga!

Postby solar_dave » Mon May 05, 2014 2:42 pm

I noticed on Thursday last week that the peak solar output was down about 10-12%. Ran over to my 2 central inverters and sure enough, one was producing 25% less than the other. Thought about this for about 5 minutes and realized one of my strings of panels were not producing. I have 8 strings of 9 panels each and the the fused combiner is in my attic. Well my left leg is in such bad shape I can't do that climb right now, so called an electrician recommended by my neighbor. My regular guys will not touch the DC side of the solar system.

The electrician showed up @ 9:30 AM before stuff got really hot up there. Sure enough, the combiner had a mix of 10 amp and 8 amp fuses installed, one of the 8 amp one showed open. 8 amp fuses are kind of close to the 125% rule for fusing, so I had them replace all the 8 amp fuses with 10 amp ones. Voila, back in full production.

The original installers probably didn't have enough 10 amp fuses with them and a pile of the 8 amps ones on the truck. Lazy bastards!
Dave Shiels

My TED 5000 power monitoring
http://phx-solar.no-ip.info:8081/Footprints.html
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Re: Solar outage saga!

Postby Doug Coulter » Mon May 05, 2014 8:12 pm

Well, yay that it got fixed - the old "if you want it right, do it yourself" may apply here. My new upgrades are having their first full year of production and testing, and so far, I'm pretty happy with the results. Also, I've long noticed that using heaters or not - the Volt gets far better battery miles in warmer weather, which we are finally having sometimes (this is the time of year we often have all 4 seasons in a day...pick your time). Even though my Volt often says "empty" at 9.5 kwh used - I'm solidly in the 50 mile club still on a reasonably warm (over 55) day again. Nice! I'm using it more and more, and frankly, often surprised that on a medium bad day (mixed cloudy) I can go out early (for me that's before noon) and still get recharged by the end of the day for the next run. While it's a bit dodgy for periods of "dark" it's still working out well for me - mostly driving for the cost of tire wear. Hah! naysayers go prove they have something better. I dare ya.

Next project on this...I had the latest greatest led lighting tech from 10 years ago for my always-on nightlghts and opsec (lose your night vision as you break down my door)...drew 40w all the time. Now the new ones draw 1w apiece (4 total) which is enough difference to power this intel NUC full time with leftover. I'm not going to complain. I'm putting them and the NUC on their own 24 v system with their own trolling batteries and diode connected to the rest of the system so they are not only always on, but never-fail, even if my batter box (outdoors) and main inverter are compromised. Turns out the walmart trolling deep cycle batteries don't like the swings in volts my main flooded batteries enjoy on normal days - they die quick. So a diode drop and a PTC to keep peak currents down seems like the right move on that - more later when it's really in operation. But it looks like another major vampire load is about to be retired - the 40 or so watts for my opsec lighting goes to about 5w, and there's enough left over to power an always-on i5 NUC which has plenty of possibilities of its own.

Glad your system is back to par. Mine appears to be as well - but it's now in its first year of testing after all the major mods. Looks like my next wisest spend is about doubling my 24 kwh battery bank...the rest is super.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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Re: Solar outage saga!

Postby solar_dave » Tue May 06, 2014 9:52 am

Have you thought about running a PWM controller to your second set of batteries? I bet if you got one with a remote of some sort you could just fire it up when the extra power is coming in late in the day.
Dave Shiels

My TED 5000 power monitoring
http://phx-solar.no-ip.info:8081/Footprints.html
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Re: Solar outage saga!

Postby Doug Coulter » Wed May 07, 2014 2:15 pm

Well, for the little set, it's decided as above - extreme reliability/resilience is the main goal there. I just want those couple easy jobs done, and with a crap-load of 9's after 99% - 6-8 would make me smile (it ain't happenin, but more is better).

Should I double my main bank size...a distinct possibility, I'm not sure what arrangements I'll wind up making. We are, after all, talking about potentially 100's of amps with very little voltage drop tolerable...I may just simply hook them in parallel with the rest. It'd be nice to be able to let the Volt charge into sundown, instead of having to make sure I get a little boost at the end of every day, and to be able to live through, you know, February without running a gasoline backup generator as much. The little Honda is a real sipper on the gas - runs all day on a sub 1 gallon fill - but I burned 12 gallons of gas in it last winter. The Volt is actually more efficient in terms of kWh/gallon, but it utterly destroys your "gas mileage" figures to use it that way. And um, I could buy another Honda a lot cheaper...not that this kind of use is going to put much wear on the Volt. I think I timed it running about 90 seconds every 15 or so minutes driving a forklift battery charger that easily runs my house and even makes gain if I'm in a moderately hunkered down mode (eg not welding or fusioneering or such). Engine never even seems to reach temperature in that mode, it's not the best for it, but it's still more efficient than the Honda...go figure.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.
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