More like 20-30 and many have 20 year warranties but batteries which cost as much as the panels have a short lifespan. Charge controllers and inverters may last ten years. LED lighting, who knows. We made our golf cart batteries last eight years which is more life than most people get out of them. Golf cart batteries are the cheapest and most readily available true deep cycle. Marine batteries aren't true deep cycle, even if it says deep cycle on the label. Fork lift batteries will last 20 years but are expensive, huge and heavy weighing a few hundred pounds. Batteries made specifically for solar are cost prohibitive as are Tesla made batteries. You never really get a ROI from solar power. We has a small setup because we knew we'd be living off grid for a few years so it was worth it for us. Always had cold milk for the kids and meat and veggies in a 12vdc freezer/fridge that was a true fridge with a compressor and freon, not one of those 12vdc coolers. We ended up being off grid for 5 years and the charge controller crapped out three days before we got electric service installed so I just ran the generator a lot for those three days. Total cost of everything was $1600 which works out to $27/mth for minimal electricity. Electric co-op charges a $25/mth maintenance fee even if zero kwh is used. So $25/mth for a little electricity compared to no electricity was definitely worth it for us. If you live in a place where electricity can't be brought in or would cost a 5-6 digit price tag for installation, like in the mountains, solar is worth having. We had LEDs that I collected in the electric sign business and they're still going strong after 12 years. Batteries, fridge(china), charge controller, inverter(china) all failed at around 7-8 years. Solar panels are still good but I'd have to spend $500 on batteries and $200 for a charge controller to get the system back up and running. The LED lights are running off an RV converter/charger right now and even just a couple of golf cart batteries would give us lighting and run/charge electronics during short term power outages. Might do it someday because it is nice to have modem/router, cordless phone, TV, streaming, DVD and lighting and keep our laptops, cell phones charged when the power goes out. Where it really gets stupid is; I'd have to have a $40k system to be able to run my small, 220 volt mig welder and/or 220 volt table saw. Same with our electric range, electric dryer, electric water heater. I could swap those to propane appliances and use a generator to run the welder and table saw if I really wanted to be off grid but I kind of like having electric service. The only cost effective way to do wind power is to build your own turbine from scratch because the retail ones are either too small to do much of anything or cost a 5 digit price tag. Only about 10% of the USA is worthwhile for wind power to get a ROI or make a good amount of electricity. When/if they can make affordable batteries and charge controllers and inverters that last 30 years, then alt energy might be worthwhile.
They advertise 20-30, but the reality is much less.