Andy D's posts

Tennessee Valley Authority, which covers most of Tennessee and some of Alabama, has a buy back program called Green Partners Generation that has been paying 15 cents per KwHr for every thing you can generate ( residential ) for solar/wind up to a 50 KW system size.  Starting July 1st, that is decreasing to 12 cents/kwhr, BUT that is going to be added to the retail amount you pay for power from your local distributor.....which in our case, is 9.3 cents/kwhr.....so my generation will now be 12 + 9.3 or 21.3/kwhr....which is a 42% increase for us.  ( your mileage may vary ).

With the recent increase of panels installed and some other technical issues resolved ( finally getting a tracking controller that actually WORKS ), we hope to be generating 500KwHrs/month here...which will more than offset our 900KwHrs monthly average, money wise....they may have to write US a little check !

Chris,

Old post I know, but I did claim and use the 20% credit last year AND the year before, for solar equipment.

And THIS year, the credit has gone to 30% with NO CAP like in the 2,000 buck one in the past....which is REALLY big deal, and the no cap feature means you don't have to spread your system out over several years if you don't want to like I did, partly because of the cap.

I've added more panels this year and will taking advantage of the 30% credit come tax filing time in 2010.

I'd agree with Thomas....if that is the breaker size used, that doesn't mean it's the amount of power used.  Best thing you could do is buy a Kil-a-watt meter, plug your machine into it and take a reading of the actual power consumption over a few days/weeks to see what it uses.....then you can make some informed decisions about going alternate.

Oh yeah, it was definitely a concrete truck day....actually it was also a concrete PUMP truck day.....since each of those took a bit over 2yds each and are located up on a hill above the house.....but I combined it with a pumped pour for a new root cellar roof ( 8x12 x 6" thick ) and some retainer wall block fill, so he pumped 10yds that day.



Yeah, I'm a certified "farm welder".....as long as it doesn't leave the farm, it might hold....ahahahaaaa....

Nah, I do fair at it, though if it's something critical that has to hold pressure, I go get a buddy that really knows how to weld.  I have a Miller "Bobcat" stick welder.....engine driven 16hp 200amp model that also doubles as a backup generator ( 8kw ), then I also bought a Miller MIG wire welder a few years ago....that one makes even a 'farm welder' look like they know what they are doing !



MX-60 on one array....FX-60 ( what replaced the MX ) on the other.....I expanded once already and the MX was no longer available.

Don't know how I left you with the impression I'm off grid, because this is a grid tie system with battery backup....I have 8 --L-16's in backup....and plan to add 8 more, for a total of 1600 amp/hr....the first panels I installed were off grid for a bit while I experimented some....but then I got serious about the whole thing seeing what they would do.....

We DO have a nifty credit here.....TVA pays 15 cents/KwHr for all wind/solar up to 50kw sized system, then after it goes thru the buyback meter, we get to use that hour we produced for free IF I'm consuming electricity at the time ( which with a fridge and 3 freezers, something is always running here ), so that avoids buying that hour at 9.3cents to boot....pretty sweet deal I thought.  My goal is to get my system up to where it replaces about 1/2 what we actually use ( about 900kw/hr/month year round average )but replace ALL our bill due to the way the money works out. Then I'll quit and move on to another project.



My understanding with single axis trackers is you get about 30% more out of them ( and that seems to be holding true from what I see, playing with mine leaving one fixed in the "noon" position and letting the other one track ), but only gain 8% more on the other axis.  Since this was a "home built" deal, I decided to weld the up-down axis good and solid ( not knowing how wind would affect things.....getting a lot of "sail" area up there now )and just to make life simple.  Probably if I could come up with a good, solid, manual design to crank it up-down, I might...but I'm happy with this.  I have less than a 1000 bucks in each tracker, and that blows away the prices I see for active trackers this size...and I suspect my design is  a LOT more stout....I tend to way overbuild stuff.

BTW, we're coming up on our first "MEGA watt/hour".....1,000 KwHrs.....should happen tomorrow evening or the next morning based on these new panels I got up today......we went "online" end of December 08 for buyback purposes.....it's been doing 12-13kw/hrs a day lately, and now we're upping that by 6 panels ( 50% ), so we should be cranking out 18 or so per sunny day....the fans never shut off in the inverters on a days like this...ahahahaaaa.....but that's ok....that waste heat isn't wasted....it's going into my greenhouse (solar gear room is on one end of it )......the tomatoes love it.

I'm not a big fan of waste.........especially when I paid so much to get it.....ahahahaaaaa

andy

Dave,

Am I understanding you are saying by connecting 3 pairs of panels in series, doubling the voltage, that my output on 6 panels would rise from 930-950w range to the 1200w range ??

I guess I don't understand HOW that would happen ?  Does the MX-60 do THAT much better with higher voltage ??  If so, all I can say is WOW !!  and THANKS Outback.

You've got me REALLY curious now.....I'm gonna run out tomorrow and slap two more panels on one array, and wire all 8 in pairs.....then compare it to the other array and see how it does.  ( I have two arrays of 6 panels each )

The tracker mounts are some homemade deals I welded up.

The are simple....a "H" frame of 1.5" square tubing, with the center part being a shaft of 2" steel, 4' long, mounted in two pillow block type bearings.  The bearings are bolted to the flat face of a pc of 8" x 2" steel channel.  The channel I welded to a 10' of 6" sch40 steel pipe, cut at a 37 degree angle. ( 1/2 way between summer/winter angles for here ) The pipe is anchored in a 4x4x4'block of poured concrete in the ground, with the sloped channel due south.

Then I welded 8' lengths of electrical Unistrut perpendicular to the "H" of square tubing that pivots east-west.  The panels mount to the Unistrut using standard cam nuts for it, and some aluminum "L" clips I had made at a local metal shop.  Ran self tapping screws thru the clips into the panel frames.

The tracking is done by a 36v DC linear actuator, with a controller built by a third party.....had a lot of trouble getting a controller to work, but believe I have that issue worked out now.  It active tracks the sun thru the day, then the panels park east at night for the next morning.
I had two controllers initially, one for each array....but now I've rigged a set of relays and one controller runs both actuators in tandem.....

Thanks for the reply, Dave.


Yes, I meant the same breakers in the combiner box.....just using 4 of them now rather than the 6 currently in use.  I assumed this would be OK since I wasn't increasing amperage, but only voltage, and they are Midnite 150vdc rated. Feed wire from the array down isn't an issue....I went oversized on the wire from the start, thinking I might expand as money permitted.

I have a 60 amp fused disconnect between the array and the MX-60, but not on the output side of the MX-60, my feed runs directly to the battery bank, then I have a 2-175amp breakers between the battery bank and the inverters ( pair of Outback GTFX2524's )

You say I can set the MX-60 to 70amp output if needed ?


And another question:

The MX-60 says it has a limit of 1600watts @24v output.

With 1050 watts of panel installed ( 6 x 175 ), the MOST I've ever seen it put out is 950watts....and typically more like 930 ( I have a homebuilt single axis tracker )......so I was thinking if I added 4 panels instead of two, that would be 1750 watts in theory ( 10 x 175ea ), but I figure it wouldn't put out more than 1600 ACTUAL watts, keeping me within the limits of the MX-60 rating.  Possibly, sometimes it would briefly run over that ( right sun conditions, reflection off winter snow, etc ), but most of the time, it would be most likely right at or slightly under the 1600w.  Trying to get the max panel on an array without changing the CC.

Bad idea or not ?

I have 6 Solarworld 175w panels currently connected in parallel to an MX-60. Each panel runs into an combiner box at the array, one panel per 10amp breaker, then on to the MX-60.....

Panels put out 4.7amp @35v. I have the MX-60 set for 24v output to my battery bank.

I want to add 2 more panels to the array, but the combiner box will only hold 6 breakers....and want to avoid going to a 12 circuit box for the expense and pain of install.

My question is can I connect the 8 panels in pairs of two in series, and run them thru 4 breakers on the combiner box, still putting out 4.7amp, but now at 70ish volts.....will the MX-60 have any problem stepping down that 70v to 24 on the output side ?

Thanks

Ah, William.....

That wasn't a "put down", merely passing on TO THE THREAD what I read in the Outback literature in an attempt to help locate the source of problems.  I used the term "cheaper generator" to differentiate what OUTBACK calls a "PRIME POWER" generator. 

In fact, my reference was more to the original poster with a Craftsman 5kw unit, which I would definitely NOT consider a "primer power" unit, but more a temporary use generator.


When I "put you down", as I NOW am, you'll be quite aware of being taken to the woodshed.  I'll make it a point to avoid giving you any help in the future, sir....and you have a dandy day.

Assuming you have good solar exposure, you really don't even need supplemental heat. Woodmizer ( the band saw manufacturer ) sells plans and a kit with the fans.

http://www.woodmizer.com/us/secondary/kilns/solardry3000/solar.aspx

The design they had before this one was better, in my opinion.  It looked somewhat like this one, but the entire roof was made of some light weight metal trusses (covered with a double layer of plastic ) that hinged at the high point of the wall, so you loaded the building by lifting the front of the "roof" and raising it up.....the truss actually hung over the back of the top wall, and was counter weighted to make 'raising the roof' very simple.  The end and back walls were site built, with a walk-thru door on an end wall.

I was reading thru my Outback manuals, and it says Outback doesn't recommend using anything but a "Prime Power" generator connected to their stuff.  I take it "Prime Power" is a REALLY GOOD generator, not a cheaper one like you have.....they said they were getting inverters back as bad that weren't bad....it was the fluctuation in the power produced by the cheaper generators that were the problem.

Keith,

Do you have the manual for the Trimetric ?  ( I got a Trimetric recently and it didn't come with the manual...I just downloaded a copy from the Bogart website, and it's pretty extension....as in real heavy reading.... ).  Also, have you tried emailing them your question ?

Eric:

I have about the same setup you are looking at.....repeater for wireless internet.   I built a 100' tower at the top of my mountain, and ran 2 -#8 wires 2300' down the mountain for powering the radios.   My internet provider came up with some neat plastic conduit that looks like black plastic water pipe with a slick silicone inside and had a pull rope in it.  I just laid the conduit on the ground down thru the woods, and it's been fine for 4 years now.....I only buried it down where it comes to the shop where my power source is located.

I was laughing at your experience with the tower construction.....lot of it sounded familiar !  Love to swap photos and notes with you if we can figure a way to email without post it public....

andy

"I have a 230v 10amp well pump.  It's a franklin electric 3/4hp pump.  It has a control box in my basement.

There's FOUR (4) wires coming out of the pump.  2 "hots", 1 neutral and 1 ground. "


Your pump has 2 "hots", a ground and the last wire runs from the start capacitor in your control box to the pump start circuit....it is NOT a neutral....your pump is a 220-240v ONLY pump, know commonly as a "3 wire" pump ( they don't count the green, ground wire ). A "2 wire" pump ( actually 3 with the ground ) has the start capacitor on the pump itself rather than in the control box on the surface somewhere, and could be either a 120v or a 240v pump.

The advantage of a 3 wire pump is that if the start capacitor goes out, you can replace it by simply changing the capacitor in the control box ( most people just buy a new control box ) instead of having to pull the pump out of the well to change it ( or the capacitor on the pump ).

My understanding of the PSX-240 Outback transformer is it will do exactly what you want far cheaper than going to a DC pump or stacking another inverter since you already have the setup you do dedicated JUST to the well pump.  You would have to ask if the Outback will work with any brand inverter, but I suspect it will.

 

Can someone calculate the wire size I would need to connect a set of 6--175 watt panels at 24v from the combiner box to the DC disconnect/charge controller/inverter ( all to be located right next to each other)  Distance is 60'  I have a quite a bit of #2 copper and aluminum wire, and can parallel it if necessary.

Thanks in advance !

andy