Adding Solar Power To Our Home

Throughout the years building our home, several people have commented along the way, “Yeah, nice house, but when are you going to add solar?” I finally have the answer. “Now!”

Power outages are fairly common here in the mountains of Panama. Heck, we had one today from 11:00 a.m. until 6:00 p.m. One common reason for an outage is that big, shallow-rooted trees fall onto power lines during heavy torrential rains. Not long ago a tree fell in our neighborhood and shut us down for nearly 24-hours. Now, powered by solar, our security cameras, Internet modem, home network, phone and laptop charging, some lights, the front gate, and air pumps in the fish tanks in the greenhouse will keep running. Today was our first test and everything that is connected to the new system continued running without even a blip.

There are a couple solar companies in Panama, but the ones I contacted only wanted to sell packages, and the packages didn’t have what I needed. So I ended up importing everything, except the heavy batteries, from the States. I chose Backwoods Solar (I am neither affiliated nor sponsored by them) as my supplier because actual humans answer the phone. I worked with David, who patiently helped me design our system and answered each and every stupid question I could think to ask. It was like shopping at a boutique rather than a big-box store.

I knew virtually nothing about installing solar power, and this was less a learning curve and more like climbing a shear cliff wall. But with David’s help and with the generous assistance of my friend Zach here in town who helped me work through the myriad of menus and system parameters, to my amazement, it is up and working as well as I had hoped.

Starting on the roof, we have four, 100-watt solar panels. Sitting out on our bedroom porch one nice afternoon, Cynthia, knowing my affection (or is it affliction?) for dreaming up linear actuator projects said, as a joke, “Oh, you could use linear actuators to move the panels to face the sun.” Well, I hadn’t planned on that at all. I didn’t even know it was a thing. I was just going to mount the panels on the roof and be done with it. But I’m a sucker for the over-complicated and decided to research sun tracker mechanisms. She is very sorry she mentioned it.

Here are a couple photos of the solar panels installed on the sun tracker. In the first photo, it’s about 9:00 a.m. and the panels are turned nearly all the way to the east-south-east. I set the tracking software to adjust the panels to face the sun every ten-minutes. I bought the sun tracking computer and linear actuators from Eco-Worthy.

I fabricated the mounting rack for the panels by welding 1-inch by 1-inch steel tubing. Where the aluminum solar panel frames bolt to the steel mounting frame, I used neoprene washers to slow bi-metal corrosion. Three good coats of paint will serve for a while, but I imagine that I will have to put “Repaint the solar panel mount” on my every-other-year to-do list. When the wind blows, there is a lot of torque on the mounting mast. Even though the mast is made from beefy 1/8-inch steel square tubing, I had to fabricate bracing to keep the mast upright and to keep it from twisting.

Here is another view of the underside of the conglomeration of pieces and parts:

I still need to tidy up a few wires, but slack is needed because the sun tracker moves a lot.

Here is a short, mildly-entertaining video that I made:

That pretty much covers the roof-side of the system.

In the house, directly below the solar panels, in the master bedroom closet, I built an equipment cabinet in the corner of the room:

The inside of the cabinet belies the calm exterior:

I labeled everything so that I will know what everything is if I don’t open the cabinet for a few weeks – or – if someone else needs to step in and figure out this bowl of spaghetti!

In the cabinet are the main components – a charge controller to manage the charging of the batteries, an inverter to convert 12-volts DC from the solar panels and the batteries into 110-volt AC (normal house current), There is also an automatic transfer switch that, not surprisingly, automatically transfers power between grid power and generator power. Additionally, there is a lightening arrestor (the thing with the blue LED lights in it) to protect the electronic equipment, and a slew of switches, breakers, and power receptacles. The white PVC pipe at the bottom brings fresh air into the cabinet from the adjacent hallway.

The four, 150 amp hour 12-volt AGM golf cart batteries are in the bottom of the cabinet.

Here’s what 600 amp hours worth of batteries looks like:

Also connected to the batteries are two battery temperature monitors. The battery charge controller and the inverter keep tabs on the temperature of the batteries and shut the system down if the batteries get too hot.

UPDATE: Thanks to reader Jon (comment section below), I have rewired the batteries to evenly balance currents. Two of the wires aren’t technically the correct color, but that is what I had on hand. To order new cables would take several weeks and yet more $$$. The batteries don’t really know much about color so I’m okay with the imperfection of it all. Thanks very much Jon. Also, David at Backwoods Solar made a similar comment when I gave him a link to this post. Thanks David. Photo:

At the top of the cabinet is an exhaust fan — some of the equipment can get quite warm when it is called upon to deliver a lot of power. The fan is a Noctua brand ultra-quiet fan:

We have a generator on the way to power the refrigerator, freezer, plus the big water pump and air blower in the greenhouse. That will complete our backup power needs. Bring on the zombies!

Remember, ask you doctor if solar is right for you!

In other news, Cynthia has been making a chocolate mousse from coconut milk, coconut cream, and chia seeds. The link is to one of Cynthia’s favorite cooking sites as it has a lot of good healthy recipes. Have you seen the price of pure vanilla extract lately? Apparently massive storms damaged the vanilla crop in Madagascar. Cynthia switched to orange extract this time and it is delicious. Add some chocolate nibs and toasted coconut and it makes a tasty, good-for-you treat:

And this juvenile hawk and its sibling have been visiting us every day:

That’s all for now. Thanks for stopping by. Fred

10 thoughts on “Adding Solar Power To Our Home

  1. Nice build. Especially the sun tracker ! So do I understand correctly this is for standby for power outages or do you use daily ( or nightly ) for small draw like lights and fans etc. ? How much can you power with a 400 watt system ?
    I like your cat tails on the fence.
    Thanks to Jon for link to balance charging.

    • Thank you Don. Those things that I mentioned in the post, cameras, internet, network, a few LED lights, etc. and on the system 100% of the time. If grid power is working, 110 AC grid power passes through the inverter to the devices. If the grid goes down, the inverter kicks in and powers the devices from the solar panels/batteries. It’s not how much, but how long you can power stuff. The stuff I have on the system is very low draw so I could potentially go days or weeks or permanently as long as the sun is shining during the day. But put a refrigerator on the system and the batteries will drain pronto. Saludos.

Leave a Reply

Your email address will not be published. Required fields are marked *