solar instulation

[tommu56]

Here are some picture of my solar panel insulation after we had almost 3 inches of snow the day before.

A mini of Robs insulation. only 250 watts so far.

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battery box

Tom

 

[texasjohn]

Great photos..... congrats on getting it up and running!

 

[mahlers]

Very cool - which inverters are you using? I see you're using a 48v battery bank so that pretty much limits it to Outback, Xantrex or Beacon. My personal favorite is Outback - but I hear the Beacon M5 is pretty nice, too. Make sure you have a good GFI installed since you have the panels installed on a metal roof.

 

[Tig]

Very neat Tom. I would like to do a small solar installation. Just enough to keep the water pump, furnace blower and computer/network running. Keep us up to date as you use the system.

 

[mahlers]

If you have grid power available, you can easily put together a very small solar system that will also act as a whole-house backup. Basically, the grid and the solar combined will keep your batteries charged up, and when power goes out, your system switches over to nice silent battery power without you even knowing it. I don't know what the incentives/rebates are like in your area, but here in Cali you can pay for about a third of a small system from utility rebates, and then another third from Federal rebates. If you have frequent power outages, it is a much better investment than a gas generator. We lose power all the time here, and over the summer we had some really big fires around us and we lost all connection to the outside world for several weeks. My place stayed lit up and functioning normally the whole time. Pretty much made the whole system worthwhile just from that experience.

 

[stumpfield]

Nice pictures. That's a lot of battery for only 250w of solar panel. How many amp hour is your battery bank? Are you going to add more panels soon?

 

[3RRL]

Hey Tom,
Great pictures man, who took them? Is that you up on that slippery roof? Be careful.
Your system looks pretty good from what I can see. Lots of battery storage. I see you got the spill proof tubs to put them in too. Did you go with the hydrogen caps?
Wish you had a webcam for us to see the whole thing.

 

[tommu56]

Rob
I was waiting for you to ship me your old battey but couldent wait!
Yea the roof was slipery we had almost 2" of snow the day before I had to sweep off roof to get the Chicken ladders on the roof safely

Tom (stumpfield)
Trojan Battery Company - ProductSpecification

There are 8 in total 4 groups of 2 for a 12v system for 1680 ah at 20 hr rate.

i was going to get 4 2x2 but woried about being under batteried and adding new to old ones isnt good so i sprung for the 8.

I laied out mount to be able to add more panels together with outback mx60 i cna keep seriesing them and not add any wiring.

mahlers
Every thing is outback except for trimetric meter and suquare d ac panel panel I'll get pictuers when I go up again in 2 weeks of charge controller and invertor ect.

tom

 

[ctpres]

New co. here in TX may hit it big in solar. They will install enough solar on you roof to generate excess during the day which they sell to grid. At nite you run on grid. No batteries. $500 deposit refunded with interest at end of term (1 to 20 yrs). NO INSTALLATION charge and they gurantee you current electric rate for the term of agreement. They expect to make enough money on excess generated during day to cover your use at nite and show a profit. They could end up with a massive solar field and no land cost. Plant yet to be built so it is to early to know if this is ever even going get off ground

 

[RonMar]

Looks like a nice installation, but I didn't see any fuseable links associated with the battery interconnections in your system. Did I read correctly that you have 6V pairs in series, making Four 12V sets wired in parallel for a 12V system? At the very least, I think there should be a fuesable link where each pair meets the main 12V buss. As I am sure you are aware, one of the biggest hazards of battery banks is the tremendous stored energy potential. When wired in parallel, a battery fault/short on a single battery can be backfed with all the energy of the rest of the batteries and cause a serious meltdown/fire... A fuseable link on each leg that is just slightly larger than the normal use current draw of that leg(and well below the max current capacity of the conductors) will pass enough current for normal ops, but will open and isolate the problem child if a battery fails or a connection inadvertently gets shorted.

 

[tommu56]

RonMar
There is dc brakers box for each load and charge controller to the buss so the cable would have to fail or something like that.

Tom

 

[BTDT]

New co. here in TX may hit it big in solar. They will install enough solar on you roof to generate excess during the day which they sell to grid. At nite you run on grid. No batteries. $500 deposit refunded with interest at end of term (1 to 20 yrs). NO INSTALLATION charge and they gurantee you current electric rate for the term of agreement. They expect to make enough money on excess generated during day to cover your use at nite and show a profit. They could end up with a massive solar field and no land cost. Plant yet to be built so it is to early to know if this is ever even going get off ground

I'm interested. Any more info? Who gets the rebates, installer co. or homeowner?

 

[tommu56]

Hey Tom,
Great pictures man, who took them? Is that you up on that slippery roof? Be careful.
Your system looks pretty good from what I can see. Lots of battery storage. I see you got the spill proof tubs to put them in too. Did you go with the hydrogen caps?
Wish you had a webcam for us to see the whole thing.

Rob
Thanks for the concerin!

Ironically the weekend before I drilled from inside to mark were a joist was so I could mount brackets to them I walked up the roof from the lower roof with out a problem on the way back down I started sliding went off that roof to the lower. It's roof pitch is the other way caugh a rib and started rolling down that roof the hiting the skylight and grabing the ladder kept me from hitting the ground.

I have done it 100's of times on the other side of roof the main roof is 8/12 and and the porch is 4/12 but in the same direction so if I slide I stop on lower pitch with out a proble. I didn't even think about the ridge being 90 off the other roof or the drop from one to the other. I thought I would stop. That is why I put roof brackets and chinken ladders up this weekend.

Yea I didn't find any trays for the batterys yet that would fit in the battery box I'll keep looking.


The guys at backwoods solar didn't recomend the hydro caps but I did ask.

tom

 

[RonMar]

RonMar
There is dc brakers box for each load and charge controller to the buss so the cable would have to fail or something like that.

Tom

Tom
I am trying to get my brain around your system wiring. Do you have a wiring diagram? Is there an individual controller(and associated circuit breaker) for each 12V pair of batteries? Because if not, there is a lot of potential for severe damage. If the 12V pairs are just connected to the main 12V buss, you could in theory disconnect a pair and connect a motor in their place and it would draw power from the buss and three remaining 12V sets, just as your inverters do. A shorted battery or feedline on any of the 12V pairs could do the same thing and with large gauge wires, could draw ALL the available power from the other 3 sets VERY quickly. You have enough arc welding potential there to build a good sized steel structure Without fuses to isolate each cell, it has a VERY large potential for catastrophe. With the battery box lined with foam insulation, you would have a very hot fire. will your main building survive a battery box fire?

 

[tommu56]

Ron

its the same as a Traction battery for a forklift just wired a little different (they usually are in series "18: 2v cells to get 36 volts

Mine are "2" 6 volt in series to get 12volts and 4 sets in parralle to keep 12 volts but the current adds up that way.
Just like in my disel truck 2 12v in parralle for the juce to turn it over.

The invertor has a 12 volt input and an output of 120v at 2800 watts thereis a 250 amp breaker in line to stop that from being overloaded.

The invertor (outback) is protected internally and will shut dow in current or temp gets too high it is also the transfer switch and battery charger the generator hooks to it and will switch load to generator when running and if more generator power is avaiable it can charge at 100 amps back in to bank

tom

 

[RonMar]

That one circuit breaker on the inverter input would be sufficient to protect a single 12V series circuit as if you break a series circuit at any point, you interrupt current flow. But you are feeding yours with four parallel circuits.

Batteries can and do short internally. Without a fuseable link on each of your four 12V series battery pairs, you have the makings for a bomb! If one cell in one of those 12V pairs shorts, or you slip with a tool and cause a short, this will lower the voltage and resistance of that pair below the 12 buss voltage. This lesser voltage and lower resistance will be seen by the other three 12V pairs as an electrical load. Just as a weaker battery in a parallel circuit will suck up more charge current and rob energy from the stronger cells when not charging, the stronger 12V pairs will attempt to power this "load". With approx 1260AH of uncontrolled/unswitchable supply available in the three unshorted 12V pairs, They will feed this need up to the limits of that really large wiring. I would estimate that 1260AH pack can deliver many times that current(5-6 THOUSAND amps) in an instant. This means that that dropped wrench is going to weld itself inplace, turn red in about as much time as it takes to snap your fingers, and melt... Or it may skip a few of these steps and go right to spraying molten metal...

Here is a basic theory link. The diagrams and description you should be interested in are down about the middle of the page... There just happens to be a 4 battery parallel circuit with load diagram that is probably similar to what you have with your four 12V pairs and inverter. Note the 5 fuses used. The main load fuse is the largest as it should be the one that sees the most current in normal use and should be sized to carry the normal load current. It protects from a short in the load(inverter). The fuse on each battery should be approx 1/4 the size of the main load fuse as each 12V pair should only see 1/4 of the electrical load of the 12V buss during normal use.
Practical considerations : BATTERIES AND POWER SYSTEMS

I know my buildings and safety are certainly worth a couple of fuses.

Good Luck.

 

[tommu56]

Ron
I have been an electrician for over 30 years in that case you propose then any large parallel wire runs would have to have each wire protected individually!
It is common practice to parallel wires and have them on one large over current device as we wouldn't be able to work with the wires that large the NEC has provisions to cover that type of insulation.

I will take the fuse idea in to consideration.


tom

 

[Buckeye_Jim]

Tom,

I take it that your home is in Limerick, while your getaway place is in Lycoming County. What a beautiful place. My company installed a flood warning system all over the county in 2003. I spent a very nice couple of months there. While the mountains of Northern California is my home, an easy second choice would be Lycoming County. Here is a link the system there:
DataWise River and Stream Levels

Regards

Jim

 

[tommu56]

Jim
I am just above a flood control dam in the county

Here is a picture while I was up on the roof looking east


tom

 

[3RRL]

Oh man,
That's like a scene out of a movie. How beautiful Tom.