J Bentley

Hello - we live in the Smoky Mountains area of North Carolina. 4 years ago we installed 8 rooftop solar panels, MPPT controller, 48v inverter, and 6 repurposed lithium batteries. The install happened after years and countless hours of research, planning, learning, saving, etc. We didn't plan for it to be a DIY install, but pro installers said our site would not support solar. They had trucks, advertising, and a HR department to fund, and they were scrambling for low-hanging fruit -- prime grid-tie solar sites with big price tags. One pro suggested we needed "a man in a van" to help us. It took about a year to find that person, an electrician and solar expert who was also very busy and had to drive 90 minutes each way to our home for some crucial installation steps that were beyond my abilities. He also allowed us to get the system permitted in our rural county.
    I made some mistakes in the design process, which we were able to fix with a little bit of additional equipment and a lot of research hours and tinkering. The 2500w system with 13kwh of batteries cost us about $12k, not including hundreds of hours of my time designing, researching, and installing. Despite lots of help on websites, I felt like we were reinventing the wheel for our mountainous, heavily wooded site. The system has helped us through several extended power outages, and we feel a sense of relief that the sun provides at least half of our electricity on average.
   A year later we added solar thermal for preheating hot water, thanks to Gary and others at builditsolar.com . Heating water had been our biggest electricity draw, and the solar thermal system has proven to be the best value, bang for buck. For about $3000, we get 100% of our hot water for a few months a year, and a nice boost the rest of the time. Right now the evacuated tubes are covered with snow, as are the PV panels, but somehow the drainback cycle has already run several times.
   In hindsight, the only big thing I would change would be our choice of inverter. The Schneider SW4048 has been robust so far, but I think it was misrepresented as a good choice for "self-consumption," a system that harnesses as much solar as possible with minimal grid support. Now I would choose a Victron Quattro inverter - even more expensive but far more appropriate for our situation.
   Spending $15k+ on renewable energy seems like a lot, and others have done better for far less money, but the decisions we made were the best we could manage at the time. We had a deadline for federal tax credits (which have since been reinstated per the IRA). Shifting from planning into action was exciting, terrifying, and more expensive than we had predicted. But I think it was worth it. Hopefully our kid will agree in the years to come. Like Neil Young told the crowd at the end of his set, "Do what you can, people!"

Thanks to all for your feedback. While it would seem great to use these coolers for something meaningful and permanent like a building foundation, it does make me nervous to think about tons of cordwood masonry resting on the foam and/or its filling. Even if the bottoms were cut off, making the coolers into a form for a filling with predictable compressive strength, there are still other concerns. The coolers are not Faswall and were not designed to be used in construction. It might make more sense to use them as infill, but there would still be the issue of properly protecting them from the elements, rodents, etc. And even then, would the coolers eventually become toxic or shorten the lifespan of the building? I like the thought of feeding the coolers to mealworms and then feeding the mealworms to trout or chickens, but it looks like current research isn't conclusive about potential toxicity. For now I will look the other way as I walk past the pile of unwanted coolers, which are sooner or later bound for a dumpster, a creek, or maybe even some other person's building project.

Hello, and thanks for the many good postings on this site. My workplace generates a steady stream of white foam coolers and freezer blocks used for shipping medications and vaccines. We try to give the coolers and blocks away, but they often go into the dumpster. The coolers are about 14"x11" and 10" tall without the lid. Corners are rounded, and the walls are about 2.5" thick. Liquids will eventually leach out if allowed to stay in the coolers. Has anyone tried using these like Faswall blocks, perhaps packed with sand and covered with lathe/mortar, cob, etc.? I'm thinking they would work better if the lids were left off. XPS and EPS are used under footing walls, but would the cooler foam have sufficient bearing strength to serve as a footing wall? They are a good length for the 12" cordwood log ends we have, and we wouldn't need to further insulate the foam footings. Thanks for any input, as there doesn't seem to be much information about this on the web.