Covering large parking lots with solar panels is an idea that goes back decades but in America at least it’s an idea that has never really taken off.
What is the reason for that? Is it due to the overall cost or is there something else that keeps Walmart, Target, Costco, Sams Club, Malls, etc. from covering their parking lots with these panels and selling the power?
Another way to look at it: It used to be 20-25 years, so 10 is probably the best it’s ever been for ROI.
It’s better, but not good enough for people to consider it
Emphasis on the 5x selling price too. Imagine they buy at market price
Interesting. In switzerland if you sell your solar power to the power company you get between 0.03-0.10 francs per kw/h while electricity costs between 0.25-0.40 francs. The calculated ROI is still 10-15 years for most people though
And many Cantons offer to subsidize part of the installation. With increasing energy prices I bet those ROI are going end up better than initially projected.
Depending on the State power prices and tax incentives/rebates and your power consumption there are those that are getting 6-8 year ROI.
Isn’t 10 years around the expected lifetime of a panel?
They’re usually rated 20-25, but I think I read recently that some are still producing useful power after that.
Read an article on an early adopter that had over 30 year panels. They reported it was still producing around 70% of its original rated power.
That sounds like the one I’m recalling.
Solar panels are considered “end of life” when they only produce 70-80% of their rated power.
Most panels now seem to have a warranty lasting 25 years, guaranteeing that they will still be producing x% of their original capacity at that time, such as 92% or 88%. Generally a higher guaranteed percentage will cost more than a lower guaranteed percentage with the same starting output. After that time they will continue producing electricity but their output may drop faster. Someone might decide to replace them even though they’re still producing if the output seems too low.
Most batteries seem to only come with 10 year warranties, though, and DC to AC inverters might only have a 10 year warranty.