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

[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