7/9/24

I have posted about our power situation in dribs and drabs. Here is the whole story:

In April 2023 we bought the property. In June 2023, we started construction, and I’ll write another post with those details. During construction, our architect Robin asked CFE what it would take to get power poles to our location, but apparently the response was a ridiculous amount. Like somewhere along the line of half a million dollars. Someday, we might have enough neighbors to be able to pitch in together for power poles, but we were only the second in our neighborhood, and the first guy only comes up a few times a year. So conventional power was not an option for us.

As much sun as Nayarit gets (over 300 sunny days a year, according to the tourism websites), solar power was really our only option. But I was excited about it. Since I was a child I dreamed of having solar power, using the power of the sun instead of coal or other dirty fuels. By 2023 solar panels had come down in price enough to be relatively affordable. Basically $1 per watt, so a 100-watt panel would cost $100. I could do that. I also felt like having solar would be a huge advantage over depending on CFE, which is not super reliable. About once a month my parents report their power is out. It’s a normal thing in Mexico, but not great if I’m trying to work remotely, so not depending on the power grid sounded ideal. We would truly be off-grid in Mexico!

Before I moved to Mexico, I had given a lot of thought to converting a trailer into an RV (I might still do this someday). Because of that, I had done some research into setting up a solar system. I knew what a basic setup looked like. We needed the panels of course, but since panels make DC power, we would also need an inverter to convert the DC into AC power for our appliances. We would also need batteries to store power for nighttime and cloudy days. Finally, we needed a charge controller to route power to the inverter, and automatically flip our power source from panel to battery as needed.

I knew that much, but I had never put together a solar system by myself, and there were a lot of variables. Lurko finally talked me into getting professionals to design and install our system, and even after everything I still think this was the right call. It’s just too much money to risk plugging the wrong wire in the wrong place and screwing up the whole system. Better to leave this to the experts. We called around a few places, and we settled on a company that agreed to help us build an independent system (not tied to the grid).

First, we had to estimate how much power we would need. I made a spreadsheet, of course, but here are the important parts:

We would need a system that could generate at least 17.6 kilowatt hours per day.

We eventually want a system big enough to handle 2 air conditioners (one for us and one for the guest room), but we agreed we could wait on the guest room AC. So our system was designed in two stages:

Stage 1: Six 550 watt panels, a 6000 watt inverter, plus one 48ah 5000 watt battery.

Stage 2: Six more panels and one more battery.

Note that the inverter is sized for the bigger system. This becomes more important later. Also, the sales guy “threw in one panel for free,” so we actually started with 7 panels.

The Stage 1 system was estimated to make 18,150 watts per day, assuming we only get 5.5 hours of sun. Here, on bright summer days, it’s actually closer to 7 hours, but we always estimate worse-case scenario. Anyway, it seemed like it would be enough, especially with that free seventh panel plus “300+ days of sun.” Later we can expand to a bigger system and run two air conditioners, so people staying in the guest room can be comfortable too.

We signed the contract on November 30, and installation was to begin on December 15. We were happy, because the water had already been connected and the water pump purchased, so we could move in the house by Christmas!

What actually happened….

Because this is Mexico, and the entire month of December is chock full of holidays and posadas and other Christmas parties, installation took longer than expected. But at last, everything was connected and we had power. We moved into the house on New Years’ Eve. Plugged in the fridge, everything ran great. At 4am, we were awakened by the loud beeping of the alarm, signaling the battery was under 20%. In a panic, we shut the whole system down. The next few weeks was a lot of back and forth with the panel company trying to troubleshoot. During the day, everything ran great and no problems. But at night, something was draining the battery and causing the alarm to go off. They checked the battery and the connections, everything was fine there.

We finally figured out, after we ran nothing but the inverter for a night, that the inverter was eating 30% of the battery, and I had not accounted for how much power the inverter itself consumed. Our inverter was meant for a much larger system, but it was cheaper to just get the larger one now instead of buying a smaller one and then changing it out later. The engineer confirmed (and it was tough to get him because he serviced several locations across 2 states) that yes, that was the normal amount of power the inverter used. We were kind of stuck.

During all this, we had to figure out how to manage the refrigerator while the power kept going out. For a few weeks we were able to buy a big block of ice and keep it in the freezer- it was just the right size. Then every night before we went to bed, we moved everything from the bottom fridge into the top freezer so the food would stay cold. Then we would unplug the refrigerator for the night. In the morning, we would plug in the refrigerator and move the food from the freezer back to the refrigerator. This routine proved to be not great for an already-old refrigerator, and after a few weeks of on-and-off it gave up the ghost. We had another refrigerator, but it was still in Texas, sitting in the trailer. And until we solved the power problem, we couldn’t use it overnight anyway.

Our solution was to not use a refrigerator at all, and only run the fans, Starlink, and the inverter at night. This only used 2736 watts. Adding a refrigerator used 4128 watts. So that should still be ok if we have a 5000 watt battery, right? Nope! This is a lithium ion battery, and while you can use more of it than a regular car battery, you’re not supposed to run it down under 20%. That’s why the alarm goes off when the battery is at 20%. So what we actually have available to us at night is 4000 watts, not 5000. You can see now why running the fridge made us go over. Only by 128 watts, but still, we were tired of waking up to the alarm at 4am.

Honestly, we could have tried something else, like maybe turning Starlink off while we were asleep. But the fridge made that decision for us when it died, and we decided we would just tough it out until we got a new fridge and a more robust system. So for the last 6 months, we’ve been just using a cooler, buying ice every day, and trying to limit buying food that needed to be refrigerated. No more putting leftovers in the freezer, no more making big batches of dog food, no more making big batches of anything unless we could preserve it in a non-refrigeration way. This is why I started learning about growing and canning and drying food. It dovetails nicely with learning how to live off-grid, but that was why. We just don’t have 24/7 reliable power right now.

Again, while it’s sunny, we have very few problems. At night, we have learned what to keep on and what to shut off. We made this system work until June, and then rainy season started and we had to figure shit out all over again. On really cloudy days, the battery was not charging up to 100%. Sometimes we would go to bed and it would only be at 60%, and that was not enough to get us through the night. On those nights we had to shut off the whole system and sweat through the night with only our tiny camping fans. That was when we decided to escape to an AirBnb with AC and try to figure out what to do. Maybe we just had to move out over the summer?? We thought about it, but with no summer job I didn’t think we could afford to pay rent somewhere else. In the end we figured out how to manage power on cloudy days. If we turned off the inverter (and all the power) shortly after we got up (around 6am), that was usually enough to get the battery up to 100% by 12 or 1:00, and then we just had to be careful to not tax it too much, like by not running the AC. Thankfully, the cloudy days were less hot so AC wasn’t needed. So again, we adjusted and made it work. Still, having to leave and buy ice and food every day is a major pain, and we will be so thankful when we can actually use a refrigerator again.

The plan was to save up until June and then complete the system, but that was before the medical issue, which I was able to handle without insurance. And even then I was going to try to skate by, but then I lost my summer job and all the savings were wiped out. So we have gone past Plans B, C, D and E, and this is Plan F: borrow and fundraise so we can upgrade the system to Stage Two: 5 more panels and one more battery.

The system upgrade should solve MOST of the problems– except how to air condition the house at night. To have enough watts to run the one mini split all night, we would need 5 batteries, and for that plus the guest room we’d need a total of 12 batteries, and the ability to charge them all. At $2000 dollars a battery that’s not going to happen for a while. It’d be cheaper to buy a $1000 generator and run it for $1000 worth of gasoline a month. I’d hate to waste all that gas but I also want to be able to sleep at night. For now we’ll focus on upgrading the system, and give the AC-at-night problem some more thought.