If you want to instal solar panels...how often do you have to replace them?
solar cells never really stop producing, they just reduce their output over the years. There are many solar panels still running at 75% of their initial output and have been up for over 40 years. Most manufacturer will give you a 25 or 30 year waranty. That means that they guarantee that the solar panels will have no less than a 0% drop in the amount of electricity produced by each panel in 30 years.
I have several friends that have large systems down in Mexico where there is no electric grid. They have had these systems for years. They say you probably should plan on at least 0 years with decent output. The capacity does taper off with time so maybe half power in 5 years might be a good assumption. Here in Arizona our payback (Break even) point is about 8-9 years. Our state has subsidies along with fed, and utility company. A 3000 watt system will cost about $0,000 installed. That is about half off regular price.
My panels came with a 25 year warranty. I will have to replace the converter ($000) at some point, 2-5 year mark. I should breakeven within 6 years thanks to great rebates in my area. I've heard that they lose some efficiency over time, but I know people who have had panels for over 0 years and if they have drop off some, it isn't noticable.
One of the major solar panel manufacturers just upped their warranty period to 30 years for 90% of their rated output because the panels just keep working without losing efficiency. Of course if a large hail storm comes by you might have to replace them a little earlier..
Expect a water heating panel to last about the same as a water heater, 0 to 5 years. Actually, my brother's system is coming up on 5 years, and is not giving trouble yet, so maybe technology has advanced. I have actually never personally known of anyone replacing a solar electric panel due to wear-out. I have heard of occasional replacements due to accidents, including natural disasters like lightning strikes. And one brand of panels had manufacturing defects around the year 2000, but that manufacturer owned up and replaced those free of charge to their customers. A standard warranty on a solar electric panel nowadays is 25 years.
