My solar panel rig - One year in

Having landscaping lights is nice, and I was able to run them for many nights using my solar setup. I have three 100w panels, two 12V batteries and about 6 or so 10W LED lights that are powered by this rig. I set it up about one year ago, and at the time I really thought I would be able to power my lights consistently. Summer had its drawbacks such as the tree line blocking some of the light during the early morning and late afternoon. Though the sun is more intense during the summer. But by the winter time all the trees have dropped their leaves, giving me more light hours at the cost of a less intense sun during the winter... so its a give and take depending on the season.

But the reality is, every day is different. Some days its cloudy, others its raining. So as much as I wanted a consistent schedule for my lights to be on from around 8PM to 7AM I quickly learned its not possible with a small battery bank like mine. Mine is as small as they come, only two 12V batteries. So looks like in future builds I may really need to go over board on the amount of batteries I have, always having more amp hours than I will ever need.

Luckily I have a digital timer where I can dial in which days I want the lights to come on. At first I was doing every night in the summer. But after about three days of this it would not recover enough power during the day to fully charge them for the next night. So now I am running the lights every other night, and even then sometimes it needs a extra day to charge.

Even though I am not getting as much lighting as I am hoping, its great to have this reserve of power if I ever need it. I can hook up an inverter to my batteries and use them for emergencies. For example we may be getting snow over night. So I am letting it stay charged in the case we lose power. Having these panels could really be a luxury during a situation where we need a little juice and have none.

The wiring is holding up well, glad to have a strong enclosure to protect it from the elements.

Much thicker wires are used that go to the battery and panels. I was surprised how thick the wires needed to be to handle solar but glad I went with the right gauge wires instead of burning out finding out the hard way.

Inside the box we have my timer, and the charge controller. I wish my timer was a little more smart though. It would be nice for it to ignore the light schedule if the battery voltage is below a set value.. Like maybe below 13V it would stop the lights from coming on. That way the batteries do not get deep cycled in the case we have many overcast days in a row.

I left the wires bare inside the fire pit where the batteries are. They still have their insulation but not sleeve. Figured they were well protected from the sun with my corrugated plastic on top.

The panels could be upgraded. They make 200W panels that are the same size. And I could increase the voltage to 24V, though this would require me to wire up my batteries differently and replace the charge controller and the timer. Though if I did run at 24 volts I may have better efficiency.

Surprised how little cleaning these panels need, mostly the rain washes them clear and not much needs to be done for maintenance.

Also impressed the solar stand is holding up. I was designed to only hold two panels, though I rigged it up with three and glad to see it has not collapsed.

So what I have come away learning from this is:

You always want more batteries than you think you need, I started off with one but quickly bought a second.
Running at 24V may be a better setup than my 12V, though it would require many of my components to be replaced.
Getting better panels and doubling my solar input may help me with a more consistent light schedule.
Using a PWM charge controller may be causing a loss in efficiency, may go with a MPPT charge controller in the future.

So its possible with a 24V 600W MPPT charging setup I would get much better usage of my solar input. But for now I will leave it be and just enjoy the lights on occasionally.

Posted with STEMGeeks