Getting ready to take the plunge

verdigo

Greetings. So about six months ago I bought a 45 watt Harbor Freight solar panel kit. I was charging a few car batteries, lighting the shed and using a few power tools on a cheap Autozone 1200 watt msw inverter. The original plan involved my father who I care for. He has COPD and is tethered to an oxygen concentrator. On top of that he needs a de-humidifier to dry the air. Our longest power outage was almost two weeks due to an ice storm. I used a small 2.5k Honda generator for back-up. Our grid power is cheap at just shy of 8 cents per KW hour. Other than concerns about our economy taking a dive and possible outages from that and other unforeseen issues I have no real justifiable need for solar power. I'm calling it a hobby at this point that will leave me with a usable asset once its complete. In a true "shoot ready aim" mode of thinking I went out and bought a 280 watt poly panel and a Chinese grid tie inverter off of Craig's List. Then I bought a used 45 amp Morning Star charge controller off eBay. Then I bought another 280 watt panel. "The panels are Grape Solar by the way". Then I ran into this Forum. Re-sold the charge controller. During this time I built a PV ground mount. Ultimately I would like to be off grid with grid back-up. The house is small and all electric, and i realized I would need an out building to house the battery bank and various electronics needed so I am building a shed with room for at least 4 additional panels. I am currently looking for land to build an off grid cabin. So one day I will move my system there including the shed I'm building. This is what I have so far.

This is a view of the ground mount


I am hoping with the help of the knowledgeable folks on the forum I would like to start buying the rest of the components that I will need. Like I said I have the two 280 watt panels. I want to see how these perform before buying any more. Right now I need to make a decision on system voltage. I'm leaning toward 48 volts but would like to hear some opinions regarding that. Assuming I like the panels I have right now I have room for 8 of these, and maybe ten with some overhang past the roof and ground mount edges. I really like Midnite Solar's Classic 150. My plan is to run strings of 2 panels in series The VMP is 35.8 volts. A charge controller is my next purchase. I own and operate a European garage and I have a commercial account with Interstate Batteries. Interstate is $ proud of their products, but my warranty will be most excellent. Their 6 volt golf cart batteries are 216 ah, and about a $100.00 each. I also have a Midnite Solar MNPV6 Array Combiner, but for some reason I got 15 amp breakers. Do you guys think NAWS will exchange them for some 10 amp breakers? I am also in need of some advice on adjustable panel roof mounts. Well I guess this is enough for one post. Thanks in advance for any and all feedback.

Dennis

KnowledgeSponge

Re: Getting ready to take the plunge

Nice setup you got going there. I guess you've figured out that Solar is an expensive "hobby" by now. :cool:

I just jumped in myself. I set my initial goals VERY low, that way I have some early success to celebrate.

You'll find lots of knowledgeable people here and very good advice.

Good luck!

verdigo

Re: Getting ready to take the plunge

Thanks. I have been lurking here for a while. Expensive yes. I have no idea what the shed cost is so far. I don't get a lot of time. Just a few hours on the weekend and I only buy what I think I can nail or screw to it when I get the opportunity so I get a lot of satisfaction from any little bit of progress. I do need to get it enclosed soon before it rots.

Eric L

Re: Getting ready to take the plunge

If you go with a 48 volt bank, your current two panels won't be enough to give them sufficient charge. With those 216 ah golf carts, you'll want to shoot for around 20 amps of charging (about 10% of ah capacity in charging amps, ideally). It can be a little less or more, but that's a commonly suggested guideline. 20 amps at, say, 55 volts (near the top of the charging cycle for a 48 volt bank) is around 1100 watts before losses, which are typically around 25% or so due to the panels getting warm and losses at the controller, which would bring you closer to a 1400 watt array.

My point is that it's kind of hard to start with a big battery bank but a small array, since you won't have enough charging amps to keep the batteries healthy (unless you have another charging source).

One other suggestion I have is on the mount; you may want to reconsider the top row of legthwise 2x4s, simply because pressure treated wood and aluminum panel frames don't always play nice, although some people here have gotten it to work with spacers (not sure how, perhaps stainless steel spacers between the wood and aluminum of the frame). Could you possibly put some aluminum cross pieces there to mount the panels to? You'd likely only need 2 per row of panel.

verdigo

Re: Getting ready to take the plunge

Yeah. I know the 2 panels is not enough PV. I just want to check the panel output before committing to this particular brand. I have read some good reviews for Grape Solar but seeing is believing. I could make them paralleled long enough to get some usable numbers at 24 volts. As for the treated wood its just a base for metal U channel that in turn will support the panels. Actually I was thinking of covering them with vinyl siding.

NorthGuy

Re: Getting ready to take the plunge

Eric L wrote: »

... pressure treated wood and aluminum panel frames don't always play nice, although some people here have gotten it to work with spacers (not sure how, perhaps stainless steel spacers between the wood and aluminum of the frame).

I used anosized aluminum brackets. Anodized aluminum is supposed to be ok in contact with pressure treated wood. Not enough time has passed, but after 1/2 year there's no signs of corrosion.

vcallaway

Re: Getting ready to take the plunge

Getting ready to make a leap myself. On one hand 12 & 24v hardware is lower cost, but 48v has the best long term prospects. Mostly because inverters in that class are stackable to increase capacity. I think in my case I'm going to go all out on a charger and get the Midnight Solar 150 classic. I'm going to stick with my existing 12v inverter for now until I need more capacity then make the jump to 48v. Downside is I will only be able to use 6 of the 10 220w panels I ordered. Not ready to spend a couple grand more right now to get the inverter.

Eric L wrote: »

...pressure treated wood and aluminum panel frames don't always play nice...

I'm planning on building a wood mount myself. I was going to use Z feet to mount to the wood. Does that method seem to work ok?

NorthGuy

Re: Getting ready to take the plunge

vcallaway wrote: »

I'm planning on building a wood mount myself. I was going to use Z feet to mount to the wood. Does that method seem to work ok?

Here you can find a similar design to what you're going to do.

ChrisOlson

Re: Getting ready to take the plunge

I didn't take a photo of the lags, but in the background of this photo laying on the workbench you can see them. I got them from a local solar installer and they use them to install Lumos rails for rooftop solar installations instead of L or Z-feet. They are stainless steel with a lag screw thread on one end and 3/8" NC thread on the other end.

Attachment not found.

--
Chris

vcallaway

Re: Getting ready to take the plunge

Thanks for the link on the mounting ideas. Good info there.

Verdigo, do you have a good source for recycled batteries in your area? I bought 4 8d batteries from my local recycler about 5 years ago. They are still going strong and were less than 1/2 what new ones were.

verdigo

Re: Getting ready to take the plunge

No used batteries searching Google locally. My Interstate battery guy says they have them from time to time. He shows up at my shop every two weeks and my plan is to buy four every month for two months. Its not as painful on my wallet to go this route.

ChrisOlson

Re: Getting ready to take the plunge

verdigo wrote: »

I own and operate a European garage and I have a commercial account with Interstate Batteries. Interstate is $ proud of their products, but my warranty will be most excellent. Their 6 volt golf cart batteries are 216 ah, and about a $100.00 each.

The Interstate golf cart batteries are every bit as good as the Trojan T-105's, and less money. There is two area golf courses here and the Interstate ones are all they use at both places because they have gotten excellent service from them.

But the ones I've seen are 232ah @ the 20hr rate. They are GC2-XHD's.
--
Chris

Blackcherry04

Re: Getting ready to take the plunge

ChrisOlson wrote: »

The Interstate golf cart batteries are every bit as good as the Trojan T-105's, and less money. There is two area golf courses here and the Interstate ones are all they use at both places because they have gotten excellent service from them.

But the ones I've seen are 232ah @ the 20hr rate. They are GC2XHD's-.
--
Chris

I really don't have a beef about this, because I don't know that it makes a difference. Interstate GC-2 XHD's have very thin plates, if you look down in them you'll see they have many more than most GC-2's. How I found this out was a Owner had used a watering jug that had a spring loaded spout and he poked it down into the plates and bent them over and shorted out a couple of the batteries. They were all paralleled so it showed as low capacity. I took them in for the core charge and 3 years later, I'm still using them, I took a wooden paint paddle, split it and straightened them all back out, gave them a EQ and they were fine.

ChrisOlson

Re: Getting ready to take the plunge

Blackcherry04 wrote: »

I really don't have a beef about this, because I don't know that it makes a difference. Interstate GC-2 XHD's have very thin plates, if you look down in them you'll see they have many more than most GC-2's.

I don't really have a beef about it either. Just that I know the guy pretty good that owns one of the golf courses. He told me he's bought new golf carts that come with Trojans and he's been using the Interstate ones as replacements for going on 10 years. He said they last just as long as the Trojan batteries for him. And we've been to the other golf course and I've looked to see what kind of chargers and batteries they got - they got Interstate batteries in all their golf carts there.

And these golf courses severely abuse those batteries on a busy weekend. They run 'em until the cart will barely crawl back to the club house under its own power. Then plug it in and try to throw a charge on the batteries before the next customer wants the cart.
--
Chris

verdigo

Re: Getting ready to take the plunge

ChrisOlson wrote: »

I don't really have a beef about it either. Just that I know the guy pretty good that owns one of the golf courses. He told me he's bought new golf carts that come with Trojans and he's been using the Interstate ones as replacements for going on 10 years. He said they last just as long as the Trojan batteries for him. And we've been to the other golf course and I've looked to see what kind of chargers and batteries they got - they got Interstate batteries in all their golf carts there.

And these golf courses severely abuse those batteries on a busy weekend. They run 'em until the cart will barely crawl back to the club house under its own power. Then plug it in and try to throw a charge on the batteries before the next customer wants the cart.
--
Chris

This is good to hear. I am an Interstate retailer, and stock automotive batteries particular to European cars. One of the main reasons I'm buying Interstate is I can warranty my own batteries. Not that I would behave dishonestly, but if I have a problem I get really good service. The batteries are bought on consignment so I am able to pay at a rate of one or two a month which takes a lot of the sting out of paying for 8 batteries all at once. I'll double check amp hour rating. Maybe they sell more than one grade. They do this with auto batteries ie 24, 36, and 48 month replacement warranties.

Photowhit

Re: Getting ready to take the plunge

On the construction, I would have put a header when framing in the door.

I did my own mounts out of aluminum angle and placed plastic spacers between the aluminum and the PT wood, SS nuts 'n bolts. The year following I added a couple panels with out the spacers figuring I would remount them within the year, 4 years later I remounted them and the aluminum showed little to no effect of being against the PT wood.

I used 1/4 and 3/16 aluminum, an engineer told be much larger that the thickness of the panels aluminum frame isn't needed, so I used 1/8th inch angle on my new array.

SS nuts and bolts tend to bind (really they meld?) I had read that different types of SS in the nuts and bolts (different amounts of nickel and chromium) I don't know if that's true but I didn't need to use any grease or wax on the original mounts at my cabin, but had to use grease and still had some binding on my new array.

NorthGuy

Re: Getting ready to take the plunge

Photowhit wrote: »

SS nuts and bolts tend to bind (really they meld?) I had read that different types of SS in the nuts and bolts (different amounts of nickel and chromium) I don't know if that's true but I didn't need to use any grease or wax on the original mounts at my cabin, but had to use grease and still had some binding on my new array.

I used SS bolts and nuts too. I knew about the grease, but I forgot to put it on. I haven't seen any signs of seizing. They were about as smooth as regular bolts.

verdigo

Re: Getting ready to take the plunge

Photowhit wrote: »

On the construction, I would have put a header when framing in the door.

I have yet to frame the door. Its just convenient to have the opening over 4 ft. to cut siding and plywood sheets there for the time being. Just pulled the trigger on that classic 150. Ouch..

ChrisOlson

Re: Getting ready to take the plunge

NorthGuy wrote: »

I used SS bolts and nuts too. I knew about the grease, but I forgot to put it on. I haven't seen any signs of seizing. They were about as smooth as regular bolts.

Stainless steel bolts and fasteners will gall if they are of the same alloy grade because they work harden at the same time. If one is made of 304 and the other of 316 stainless there is less chance of galling because the different alloys harden at different rates. They generate an oxide surface film for corrosion protection, by design. During tightening, as pressure builds between the thread surfaces the oxides are broken and interface metal high points shear and lock together in the threads. Typically, using a thread lubricant containing molybdenum disulfide or graphite is recommended on stainless threaded fasteners.
--
Chris

NorthGuy

Re: Getting ready to take the plunge

ChrisOlson wrote: »

Stainless steel bolts and fasteners will gall if they are of the same alloy grade because they work harden at the same time. If one is made of 304 and the other of 316 stainless there is less chance of galling because the different alloys harden at different rates. They generate an oxide surface film for corrosion protection, by design. During tightening, as pressure builds between the thread surfaces the oxides are broken and interface metal high points shear and lock together in the threads. Typically, using a thread lubricant containing molybdenum disulfide or graphite is recommended on stainless threaded fasteners.

Mine were all 304. But either because it was cold, or because I didn't tighten them that hard, or because they were too small (5/16), or may be I just got lucky, but fortunately I didn't get any galling.

wpb1971

Re: Getting ready to take the plunge

wow This shed is awesome. Really cool.

verdigo wrote: »

Greetings. So about six months ago I bought a 45 watt Harbor Freight solar panel kit. I was charging a few car batteries, lighting the shed and using a few power tools on a cheap Autozone 1200 watt msw inverter. The original plan involved my father who I care for. He has COPD and is tethered to an oxygen concentrator. On top of that he needs a de-humidifier to dry the air. Our longest power outage was almost two weeks due to an ice storm. I used a small 2.5k Honda generator for back-up. Our grid power is cheap at just shy of 8 cents per KW hour. Other than concerns about our economy taking a dive and possible outages from that and other unforeseen issues I have no real justifiable need for solar power. I'm calling it a hobby at this point that will leave me with a usable asset once its complete. In a true "shoot ready aim" mode of thinking I went out and bought a 280 watt poly panel and a Chinese grid tie inverter off of Craig's List. Then I bought a used 45 amp Morning Star charge controller off eBay. Then I bought another 280 watt panel. "The panels are Grape Solar by the way". Then I ran into this Forum. Re-sold the charge controller. During this time I built a PV ground mount. Ultimately I would like to be off grid with grid back-up. The house is small and all electric, and i realized I would need an out building to house the battery bank and various electronics needed so I am building a shed with room for at least 4 additional panels. I am currently looking for land to build an off grid cabin. So one day I will move my system there including the shed I'm building. This is what I have so far.

This is a view of the ground mount


I am hoping with the help of the knowledgeable folks on the forum I would like to start buying the rest of the components that I will need. Like I said I have the two 280 watt panels. I want to see how these perform before buying any more. Right now I need to make a decision on system voltage. I'm leaning toward 48 volts but would like to hear some opinions regarding that. Assuming I like the panels I have right now I have room for 8 of these, and maybe ten with some overhang past the roof and ground mount edges. I really like Midnite Solar's Classic 150. My plan is to run strings of 2 panels in series The VMP is 35.8 volts. A charge controller is my next purchase. I own and operate a European garage and I have a commercial account with Interstate Batteries. Interstate is $ proud of their products, but my warranty will be most excellent. Their 6 volt golf cart batteries are 216 ah, and about a $100.00 each. I also have a Midnite Solar MNPV6 Array Combiner, but for some reason I got 15 amp breakers. Do you guys think NAWS will exchange them for some 10 amp breakers? I am also in need of some advice on adjustable panel roof mounts. Well I guess this is enough for one post. Thanks in advance for any and all feedback.

Dennis

Photowhit

Re: Getting ready to take the plunge

ChrisOlson wrote: »

Stainless steel bolts and fasteners will gall if they are of the same alloy grade because they work harden at the same time. If one is made of 304 and the other of 316 stainless there is less chance of galling because the different alloys harden at different rates. They generate an oxide surface film for corrosion protection, by design. During tightening, as pressure builds between the thread surfaces the oxides are broken and interface metal high points shear and lock together in the threads. Typically, using a thread lubricant containing molybdenum disulfide or graphite is recommended on stainless threaded fasteners.

Thanks Chris, Much more intelligently put than my poor explanation! Wonder if I have to take down my new array, is I'll end up cutting off the nuts and bolts, all I had was some No-OX grease...

SkiDoo55

Re: Getting ready to take the plunge

Any lubricant on the stainless steel fasteners will help.
When you use anti-seize use the silver type and not the copper colored. Copper type will help cause corrosion if in contact with aluminum panel frames or structure.
On any fasteners that were assembled dry you can try pretreating them a few hours before you need to remove with a penetrating oil
Enjoy your project

westbranch

Re: Getting ready to take the plunge

Chris, do you remember the brand for those Panel Clamps, they look like S-5's but not quite...

ADD: Also what about usiing Nylock nuts with SS bolts? IIRC they are aluminum with the nylon insert..(?)

ChrisOlson

Re: Getting ready to take the plunge

westbranch wrote: »

Chris, do you remember the brand for those Panel Clamps, they look like S-5's but not quite...

I don't know for sure what the brand is of the mid and end clamps. The rails I used are Lumos PowerMount 2.0's. I got everything from a local solar installer and he grabbed the clamps, bonding clips, and all the stainless hardware out of boxes on the shelves in his warehouse, and I never did see the brand on those.
--
Chris

Photowhit

Re: Getting ready to take the plunge

westbranch wrote: »

Also what about usiing Nylock nuts with SS bolts? IIRC they are aluminum with the nylon insert..(?)

I used SS nylock nuts on all my installs;

Attachment not found.

NorthGuy

Re: Getting ready to take the plunge

westbranch wrote: »

Also what about usiing Nylock nuts with SS bolts?

I used nylock SS nuts to connect panel to braket.

However, I used split lock washers to connect brakets to wood frame. As wood expands and contracts, the washer is supposed to maintain the pressure. May need to tighten them more after couple years.

verdigo

Re: Getting ready to take the plunge

ChrisOlson wrote: »

The Interstate golf cart batteries are every bit as good as the Trojan T-105's, and less money. There is two area golf courses here and the Interstate ones are all they use at both places because they have gotten excellent service from them.

But the ones I've seen are 232ah @ the 20hr rate. They are GC2-XHD's.
--
Chris

The Interstate batteries I'm getting are GC2-XHD-UTL. They are marked 216 ah.

inetdog

Re: Getting ready to take the plunge

NorthGuy wrote: »

I used nylock SS nuts to connect panel to braket.

However, I used split lock washers to connect brakets to wood frame. As wood expands and contracts, the washer is supposed to maintain the pressure. May need to tighten them more after couple years.

Dish type (Belleville?) washers will do a better job of maintaining pressure. The split lock washers have greater benefit in keeping the nut from vibrating loose, but the Nyloc should take care of that part.

ChrisOlson

Re: Getting ready to take the plunge

verdigo wrote: »

The Interstate batteries I'm getting are GC2-XHD-UTL. They are marked 216 ah.

Hmmm. Right here on Interstate's website is the GC2-XHD-UTL - it says CAP-20 (20 hr capacity) is 232, and that's the only ones I've seen. It's a direct replacement for the Trojan T-105.
http://www.interstatebatteries.com/cs_eStore/Content.aspx?dsNav=Arpp~12,A~Part+Number,N~2147384911-2147384722-2147384903,Nr~AND%28P_unique_id%3ATrojan+T105+GC2-XHD-UTL%29
--
Chris

verdigo

Re: Getting ready to take the plunge

ChrisOlson wrote: »

Hmmm. Right here on Interstate's website is the GC2-XHD-UTL - it says CAP-20 (20 hr capacity) is 232, and that's the only ones I've seen. It's a direct replacement for the Trojan T-105.
http://www.interstatebatteries.com/cs_eStore/Content.aspx?dsNav=Arpp~12,A~Part+Number,N~2147384911-2147384722-2147384903,Nr~AND%28P_unique_id%3ATrojan+T105+GC2-XHD-UTL%29
--
Chris

I'll post a pic of the label tomorrow