Added solar power to our tractor storage building (pic heavy!)

[nikdfish]

We recently had a 22'x21' metal storage building installed to house the 1025R & 3038e and various implements. I had put in some 12v 27watt tractor worklights for interior lighting & just used one of the spare SLA batteries with an Anderson Powerpole pigtail to power them when needed. That was OK as an expedient, but not really optimal for long term.

I decided that if I was going to use battery power for lights, I needed to go all in & add a solar charging component and wire everything in properly (i.e. fuses, switches, etc.) and repurpose an existing deep cycle battery to the job. I also decided to add a couple of 12v LED motion sensor floods over the doors and to replace the 14 awg extension cord I had used for light feeds with 10 awg for better efficiency.

After looking at a bunch of alternatives I ended up going with a Renogy package consisting of a 100w panel paired with a 30a pwm charge controller, which was available through Amazon for $160, delivered. 100w may be over-kill, but it didn't really save much to go with a 50w unit, and the extra capacity will help offset the somewhat shaded location on the building south facing wall (the front). I also picked up some MC4 connectors, 10 awg wire, two 12v LED motion floods, fuse block, and miscellaneous other items.

I mounted the motion sensor floods and got them adjusted before mounting the panel because they actually arrived before the panel.

This is the Renogy package contents; 100 watt polycrystalline panel, Wanderer 30 amp pwm charge controller and a couple of MC4 connector pigtails.

I fabricated my own brackets for mounting the panel from some aluminum angle stock. I decided on a 56 degree slope on the south wall as a decent year round compromise. Because I had concerns about getting the panel mounted by myself, I decided on a bracket design that would allow the panel to be hung in place before securing the hardware. Two pieces to be attached at the top corners had "L" slots that would each engage 1/4" bolts sitting crosswise between two brackets attached to the wall. Two more pieces would be struts between clips on wall & panel.

Here are the two sets of upper brackets in place on the wall and the 10 awg feed line with MC4 connectors installed.

It actually went up pretty easily. The ladder I was using had treads that extended a bit beyond the vertical rails, so it was easy to rest the bottom edge of the panel on steps as I went up. The "L" slots worked as intended & held the panel nicely while connecting the struts.

For proximity, the controller and battery were located between the two doors. I used a plywood panel for mounting the controller and wiring. To attach it to the building, I made some clips from aluminum angle stock & attached them to the building door frame tubes. The panel then was positioned behind them and secured with screws.

(the tape held the clips in place until the self tapping screws were used to attach them)

Some boxes & cable runs were roughed in

I put in a DPST switch in the upper box for disconnecting the solar panel from the controller. The controller can be damaged by a panel being connected without a battery in place. Since the deep cycle battery I'm using also is used with a portable winch on the aluma car hauler, I want to make it easy to handle it's removal & replacement. The other two boxes are for switches for the interior lights and the exterior motion sensor floods.

This is the first version of the wiring panel, incorporating the switches, a fuse block & ground block. The battery already had an Anderson Power Pole connector, but I decided to use post clamps for the battery to controller connection. This makes it less likely for the battery to inadvertently get disconnected from the controller. The power pole connector was used for the three fuse block supply connections. The bottom position of the fuse block was used for a 30 amp fuse between controller and battery connections.

I removed the old extension cord that had been used when I first put up the interior lights and replaced it with a pair of 10 awg wires.

Just for fun, I added a couple of mini LED DC voltage displays from the junk box. One at the top of the solar panel disconnect switch, and one at the fuse block. This pic was at twilight (sun below horizon) and charging had ended. The panel voltage is reading 5.09v and the battery is showing 12.8v.

Here is another view after I did a few updates (10 awg feeds and an Anderson Power Pole pigtail to fuse block) and had a 200 watt inverter connected so I could plug in a battery tender for the 8kw generator. This is late afternoon, just prior to sun down.

These are the interior lights when illuminated.

So far things look to be working OK. Just for fun & curiosity I have a couple of inexpensive DC power monitors w/shunts coming so I can compare power delivered from the panel & power distributed from the battery. I'll post when they are installed & running.

Nick

 

[k0ua]

Nice install Nick. Have you noticed any RFI coming from the charge controller?

 

[nikdfish]

Not as yet, but I am generally not on the radio during daylight hours. The PWM charge controller is active (has LED lights on) 24/7, but I am not running an inverter full time. The building is probably 100' + away from the 160m FWL at the closest point, and much farther than that (double +) for everything else that is radio related...

Any info on the frequency range I'd most likely hear it? Any known difference in prevalence for day vs night?

Nick

 

[nikdfish]

Just a quick update. I took a little Eaton AM/FM/TV/weather radio out to the building to prospect for noise.

Standing right beside the unit, I got noise on AM sounding very much like the ignition wire noise you used to hear on older cars on AM if you didn't use suppressor wires. This faded out as the radio was tuned from 550 kHz up through about 1.6 MHz, by 1.7 MHz it was pretty much gone. On FM, it was pretty much localized around 88 MHz & sounded more like a repeated ringing. Nothing was detected on the weather channels (161 MHz & up). On the TV bands, got some noise in the intervals between channel 2 & 3 (ballpark 57 MHz ?) and 3 & 4 (ballpark 63 MHz?). Most of the above was done with the panel connected to the controller. With the panel disconnected, but battery still connected, there was still some noise being generated although the characteristics would change a bit.

All above was while standing directly in front of the panel or a bit to the side at a distance of 3 feet or less. Once I stepped outside and closed the door, I could not detect any of the above noise elements. Even putting the antenna closer to the door did not make a difference (the roll up is door a corrugated vinyl panel). I'm guessing the metal of the building, anchored into concrete, is doing a fair job of shielding.

Now that I have heard a few of the possibly noises, I'll listen for something similar when on the radio.

Nick

 

[k0ua]

Yeah the charge controller and inverter being in the metal building should help a lot to keep the "trash" inside the building. Putting a .1 microfarad across the leads going to the panel would also help to keep the leads from radiating.

 

[nikdfish]

One last (I think...) piece to the solar power thing, I added a couple of monitors, one tracking solar panel output to the controller and one tracking battery power consumption by attached loads (lights, inverter, etc.). This is absolutely unnecessary for a simple application, but I wanted to see the numbers & the cost was modest (about $40 for displays & parts).

Each monitor is using it's own ground connection shunt & they are seriously oversized for this application (shunt is good for 100 amp). This could have been accomplished with just one shunt by tracking controller -> battery vs. panel -> controller. But since one came with each display & I wanted panel side without looking at controller losses, I used two.

Displays have optional backlighting, so lit & unlit (top display is solar panel, bottom display is battery use)

This is right after install & twilight is coming quickly.

One thing I have seen so far is that the 27w worklight floods I put up in the interior are actually drawing about 18 watts each, all four on draw about 72 watts total.

The displays show volts, amps, watts and accumulated watt-hours. They have the ability to retain watt-hour data, even with power off, until cleared by the operator. If the panel feed is turned off, the top display will turn off, but the LED volt-meter will continue to show solar panel voltage.

Nick

 

[ovrszd]

You guys make me feel so inadequate.................. I have no idea what you are talking about...................:ashamed:

But I know enough to know this is a very cool setup.

 

[k0ua]

Pretty slick. Please continue to report your experiences with the system. tnx.

 

[k0ua]

You guys make me feel so inadequate.................. I have no idea what you are talking about...................:ashamed:

But I know enough to know this is a very cool setup.

Ask one question at a time and we all will do our best to answer them. "how do you eat an elephant?" "one bite at a time". You will soon discover you have a much better understanding with very little effort. Knowledge can "sneak up on you" if you will let it!

 

[ovrszd]

Ask one question at a time and we all will do our best to answer them. "how do you eat an elephant?" "one bite at a time". You will soon discover you have a much better understanding with very little effort. Knowledge can "sneak up on you" if you will let it!

Now that requires humbling oneself to the point of admission of inadequacy. I struggle there.

I'll just sit back and listen. I pick things up easily. Although I'll never know a tenth of what you know about the "radio" thing.

 

[k0ua]

Now that requires humbling oneself to the point of admission of inadequacy. I struggle there.

I'll just sit back and listen. I pick things up easily. Although I'll never know a tenth of what you know about the "radio" thing.

But you have to remember I didn't know anything about radio and electronics until I did. We must all start somewhere. Also remember there are many things about many other subjects that you know about that I don't. We all have knowledge about something, and no one person knows it all.

There, you have just passed James Philosophy class 101.

 

[k0ua]

Oh, and I have been learning on "the radio thing" for about 50 years, and what I know would fit in a thimble compared to the ocean of available knowledge on the subject. Even if you choose one subset of radio, lets say antennas for instance because they interest me to a greater extent, I still have "much to learn grasshopper".

 

[ovrszd]

I hear ya James. I know you as well as can be done in this environment. I understand where your knowledge exceeds mine by miles. I'm trying to catch up, but it'll take awhile.

 

[k0ua]

I hear ya James. I know you as well as can be done in this environment. I understand where your knowledge exceeds mine by miles. I'm trying to catch up, but it'll take awhile.

I know it is a long way to go, but if you could come down and spend an afternoon with me and my humble little station and antenna farm, I would be happy to answer any questions you might have and give you an 10,000 foot overview of radio at least as it pertains to me and what I do. We would put on some hands on demonstrations of several different modes. Your welcome any time after Dec 7th. (pearl harbor day, and it happens to be the end of the Medicare AEP)

 

[PRCWI]

Nice setup, I'm considering doing something similar in a horse shelter where we feed the horses every morning and do body checks for any injuries. I will only have the lights on daily for 1 hour or less but I want it to be well lit so I'm looking at putting 6 10w LED flood lights in a 24x42 building, so in theory my total draw would be 60w and I'd have about 4500 lumens of total light. Each light is supposed to put out 750 lumens and be comparable to an 80w halogen bulb.

Anyway, I'd be open to any input from anyone because I am flying in the dark on this other than basic research.

I was planning to do one 15w solar panel with a pwm charge controller and one deep cycle marine battery.

We live in WI so winter is as bad as it gets for solar here but I think with us only using 30-60 minutes a day that should work. Does that sound right or should I get a bigger panel?

 

[k0ua]

Nice setup, I'm considering doing something similar in a horse shelter where we feed the horses every morning and do body checks for any injuries. I will only have the lights on daily for 1 hour or less but I want it to be well lit so I'm looking at putting 6 10w LED flood lights in a 24x42 building, so in theory my total draw would be 60w and I'd have about 4500 lumens of total light. Each light is supposed to put out 750 lumens and be comparable to an 80w halogen bulb.

Anyway, I'd be open to any input from anyone because I am flying in the dark on this other than basic research.

I was planning to do one 15w solar panel with a pwm charge controller and one deep cycle marine battery.

We live in WI so winter is as bad as it gets for solar here but I think with us only using 30-60 minutes a day that should work. Does that sound right or should I get a bigger panel?

I think you better get a bigger panel. The 15 watt panel is optimistic. Panels don't really put out what the rating is in many real world conditions. If you got 6 watts out of the panel in snowy Wisconsin over a lighting period of 6 hours, that would be 36 watt hours. You plan on draining 60 watt hours per day. Not to mention losses in wiring and controller and other efficiency losses.

I don't think the 15 watt panel is going to do it for you long term. Nothing less than a 50 is going to even get close. Don't forget dark days. An 100 is more like what I would do to have some reserve. We will let Nick weigh in on this, as he has some real world experience already, and has the monitoring now in place to do actual calculations, but off the top of my head, I would say the 15 is not going to cut it.

 

[Citydude]

I'm leaning on doing this as well. Great thread as I'm learning at a faster rate than googling questions...Thanks!

 

[nikdfish]

My panel location is going to complicate comparison to systems more optimally placed. The front of the building is "soft" shade (i.e. no hard edges) from surrounding trees most of the time, even on sunny days. That was one reason for going with the 100w panel, to try to compensate for that situation. From what I have read, "soft" shade tends to reduce current more so than voltage, "hard" shade (like an object directly blocking the light) drops voltage as well as current.

Another factor is the battery in use; I am using a RV/Marine deep cycle, rated at 105 AH @ 20 hours and 635 CCA. It has some age on it & at one point, a while back, a fair portion of the plates were above electrolyte after sitting with a battery tender for an extended time & the level brought back up with distilled water.

On the plus side, the battery is getting charged, but not very quickly. After several days, the controller indicator still stays on "normal charge", I have yet to see it get to a "float" charge condition. Morning (just after sun up) battery voltage has been increasing over time, the first morning after install it was showing 12.6, a few days later it is showing 13.1 as a morning voltage. (These are numbers while connected to the controller, not true "resting" battery values.) Typically the only draw on the battery has been the two 10w LED motion floods that stay on all the time, with only very short periods of the internal lights (mostly just during some testing).

The first day+night period after the meters were installed, it looks like 19 watt hours were delivered & consumption was too low to record. I don't know if it is the shade situation, or maybe that the battery is charged to the point the current is getting tapered off. Possibly a combination of both.

I swapped meters between shunts to see if I had a mismatch (meter/shunt), but got the same (reasonable) watts value for interior light consumption from both, so it looks like they are properly paired. (Sidenote: Shunts for these meters supply 0.75 mv at full scale. A meter built for a 50A shunt would read low by 50% if used with a 100A shunt). I zeroed out the watt/hour totals on both after the switch.

I haven't talked to the Renogy folks yet to see if my numbers are reasonable, but will probably do so when I have accumulated a bit more information.

Nick

 

[PRCWI]

I think you better get a bigger panel. The 15 watt panel is optimistic. Panels don't really put out what the rating is in many real world conditions. If you got 6 watts out of the panel in snowy Wisconsin over a lighting period of 6 hours, that would be 36 watt hours. You plan on draining 60 watt hours per day. Not to mention losses in wiring and controller and other efficiency losses.

I don't think the 15 watt panel is going to do it for you long term. Nothing less than a 50 is going to even get close. Don't forget dark days. An 100 is more like what I would do to have some reserve. We will let Nick weigh in on this, as he has some real world experience already, and has the monitoring now in place to do actual calculations, but off the top of my head, I would say the 15 is not going to cut it.

That's what I was wondering. It will be south facing with full sun but I certainly don't want to have the panel end up too small.

If my calculations are right I'll be drawing 60w @ 12v which should come out to 5amps for one hour (so I think that means 5amp hours of drain on the battery per day?) so the panel would need to be able to replenish that.

 

[nikdfish]

After checking everything out, the equipment looks fine - but the location kills the efficiency. After checking out the panel by itself "as installed", I dismounted the panel from the wall and took it to full afternoon sun and put my meter on it. It produced, pretty much, as specified in the documentation 22.35 volts open circuit & 5.77 amps dead short (docs say 22.4v @ 5.92A). The installed location pretty much robs it of over 90% of its potential. The best readings, isolated in the installed location, were like 20.5v & .40 amps

Cost of conductors are too high for relocating the panel, so I'll leave it as is for now. It pretty much performs like a smart trickle charger. It does add to the battery charge, just not very quickly.

At some later point I may re-purpose the panel & charge controller elsewhere (pond pump or outdoor lighting feature?) & just start swapping out charged for discharged batteries as needed in the building.

So the word to the wise is that location trumps output capacity. I'd say you really need full sun for at least a good portion of the day to make solar worthwhile.

Nick