My batteries have a 19-year warranty guaranteeing a gradual decline in throughput to 50% at the end of the warranty. That's part of the math on it paying for itself. The same with my solar panels having a 25-year warranty declining to 70% efficient at the end of the warranty (slowly losing 30% along the 25-year span).
Once I realized that a solar system's decline in throughput is less per year than energy costs inflate each year, that was when the math worked in my favor. Basically I have warranties on only a slow decline in my solar system. We have no warranties that energy costs will go up only slowly -- quite the opposite. The Dims promise to keep jacking up energy costs to force us to repent from our cow farting sins.
Our home and property is paid for. The HELOC would have us get a loan on our house which we wouldn’t do since we are on limited income. We have savings but want to save that for when we can’t take care of the property ourselves and/or have to go to a care home. Also you never know what the government will do in the next few years. It’s a heck of a situation. Would love a windmill for our pump also (we get wind a lot here and a lot of dust from the farms around us when the wind gets really frisky.