Building An Off Grid Home In TN

Re: Building An Off Grid Home In TN

Putting the panels at a higher angle might also improve the electrical output through reflection off that white roof. Folks have reported seeing more juice when there's snow on the ground than when there is no snow on the ground, your roof would be like year round snow in front of the panels. You should be able to use the existing hardware to raise the panels as Niel advises.

Aside from that I'm extremely jealous of your place. Wish my wife was more willing to live in the hills, but she's a Florida girl and likes being in a place so flat you can see the curvature of the Earth off in the distance. I was raised where there's mountains and don't feel comfortable if I can't see them. Our retirement plot in Arkansas is a compromise, flat land at the base of a mountain .

How are you heating the place?

Re: Building An Off Grid Home In TN

ok it was late and i overlooked this as i read much of what was there by you in the thread and not just ch10. i don't see the battery ah rating listed or did i overlook that too? from you on the other site:

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That is basically our whole set up. We will be adding 5 more solar panels for a total of 8 and possibly one more invertor for more amps.

Here is a breakdown of our system components and the costs:

12 6volt batteries $940.00
Battery cables 40.00
8 135watt each Kyocera PV Panels 5200.00
Outback Flexmax 80 Charge Controller 650.00
Air Breeze Wind Turbine 600.00
Poles and anchoring for the wind generator 85.00
Outback VFX2812 Invertor 1950.00
All wiring, panels, and electrical parts 500.00

Back up Honda generator 1800.00

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as to what kyocera said, yes they will work at 1 inch, but reduced as you will see by any output curve for a pv with higher temps. and it is true that you will need a better angle than that to properly capture the sun's energy as it should be your latitude degrees for the overall average or your latitude +15 degrees that many like to go with for improved wintertime collection. the angle i see you have may work ok for summer use only. you also did not say the direction the pvs face either as i had asked.
i am only trying to let you be aware of some aspects that would allow for better operations for you and your husband and a better understanding for us as to what you have, but as my concerns have been duly noted by you you may do as you wish and continue to just say all is there when you failed to address concerns of mine that still aren't listed there that i asked about.
you can keep it somewhat simple, but the simplest isn't always right or best or your husband would've also gone with straight pwm ccs as well rather than a quality mppt cc if he was keeping it that simple. do know there's nothing really that simple about solar power generation or everybody could make and build their own pvs, controllers, inverters, etc., but for appliance operators (you know those that know nother more than flipping a switch) i suppose the light=power concept will work well enough for them as beyond that they have difficulty. most of us are to varying degrees somewhere far above keeping it that simple. i'm not implying anything here either, but you and your husband need to up it a notch to make it work better or you may find yourselves not producing very much power in the winter no matter if it never snows.
i'm also curious as to why you elected to go 12v rather than 24v for the batteries? that would be the same number of batteries, but losses can be lower by upping the voltage. in fact i also asked how the pvs were to be wired and that wasn't answered as initially you were going to go with 2 strings of 3 in a post here on this forum a few months back, but you have opted for 8 pvs i see and there's no mention of the wiring arrangement that i saw for the pvs. being you have 3 in now you either have them all in series or all in parallel. having all 3 in series would mean you'd need 1 more pv to have 3 paralleled strings of 3 in series so i'm guessing all are in parallel. wire losses can be lowered by placing series strings of 2 pvs and then paralleling the 4 strings together for a 12v battery setup. if you go to 24v on the battery arrangement (inverter already at 12v and no change possible without 24v version of the inverter) then either a 36v or 48v arrangement on the pvs may be done.
the wire is important too as we do not know the gauge from the pvs, battery interconnects, or the battery to inverter or their lengths and there's more wired stages i didn't mention, but i hope you get the drift that all of the wired stages need addressed. did he figure in the voltage losses or did he kiss it and let lowes tell him what to put in? i hate pulling teeth so please volunteer what we need to know as all isn't there.

Re: Building An Off Grid Home In TN

Interesting. From the pictures and the various sun angle, I guess their house is facing east. The new 6 PVs are facing south probably around 35-degrees, not bad. The first set on the roof is a few degrees facing east. Some one reminded them to check on the angle of the first set to maximize power production but it seemed to be ignored. Similarly with the dripping loop on the PV wires. I wonder what made them decided to get the 2nd PV set, whether they did estimate on their daily power usage to size the PVs and the battery. The first PV set on a tracker probably gives them enough power boost from the angle they placed it. So now thay have ~1600W PV on a 12V system i.e. 135A charging. She mentioned they are using some DC lighting. That's probably what they decide to use 12V inverter. They did replace the fused breaker box with MN DC disconnect. The batteries are 12 225AH GC2 type, probably not enough for off-grid to last more than a day without sun and the batteries probably won't last long with daily charge/discharge. She mentioned they will move them away from the house eventually. Hope they realize the power loss with 135A DC going from a distance and the cost of copper wires to support that high current. In one post, she mentioned they are in a county where building codes are not enforced. They were in contructions in NY, NC, FL, so I think they follow codes but not to the Ts.
GP

Re: Building An Off Grid Home In TN

You're right, the 2nd set is definitely more toward south. The first set is 90-degrees clockwise from the 2nd. That would make it westward. I was wondering if the wind gennie poles would cast their shadow on the PVs on the roof. Recent picture clearly shows that. Over the past week, they moved the 1st set off the roof to be close to the 2nd set. I guess, they are OK now. Maybe the wind would make up in the winter for that 35-degrees or so angle. With the 2 poles bracketted to the ceiling frame, the metal roof, I wonder whether the acoustic ceiling tiles could filter out the wind noise or the vibration of the pole.
GP

Re: Building An Off Grid Home In TN

The brackets are shown on page 15 and 52. They probably took off the one close to the battery box recently. With that high pole, the wind gust would give quite a vibration. I wonder when they finish their ceiling tiles, the hollow attic would act like a sound box for the wind/vibration noise.
Yeah, that slight overlap may be OK for winter sun angle. For high noon sun in summer, if the whole top cells are partially shadowed, that would cut a bit of power production.
They put the relocated PVs on another CC, probably figuring the STC 1600W is exceeding the FM80 at 12V. And they are talking about maybe getting another set of batteries. Too bad, if she had followed up on this board on PVs and wind turbine, they probably wouldn't have had to trial and error like that. Hope they learn about battery care on those GC2s before getting serious on a set like the Trojans.
GP