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?
One of the Costco locations in Albuquerque has a solar covered parking lot. Inside they have a meter showing how much of their used electricity is from the solar.
Installing and maintaining solar panels costs a lot. Perhaps the businesses found that not profitable.
In Hong Kong, we have a “install solar panels on your roof” project, and the electricity company buys the power you generate at approx. 5x market price. It sounds great at first, but people quickly realized installation and maintenance cost so much, you can only get back what you paid for after 10 years.
This may not be relevant to the discussion because we are talking about big space, and HK houses are small area-wise.
you can only get back what you paid for after 10 years.
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
They’re usually rated 20-25, but I think I read recently that some are still producing useful power after that.
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.
That’s actually part of the point. Installing and maintaining solar panels on the roof is expensive. Installing them essentially on open ground ought to be significantly cheaper
You have to have a roof to have a building. It’s a built in cost. The only extra is expensive in a buisness roof build out is more electrical wiring and panel supports. You can also generally walk between them to maintain them.
Putting panels on the roof, especially the generally flat and accessible business roofs is way easier and cheaper than building out entirely new 12ft high buildings with trenched cabling and then adding panels.
No buildings, just solar panels on poles. You don’t risk the roof or the stores business. You can use heavy equipment like trenchers. No one has to set up scaffolding or risk a potentially deadly fall.
We have huge amounts of real life evidence that solar panels on poles in an empty flat elf are far cheaper to install and maintain than solar panels on a roof, especially a business that wants to stay open.
Solar panels on poles is probably somewhere in between. It seems like they’d be much cheaper, like solar panels on poles in a field, but I don’t know if real life bears that out yet
Making the panels high enough off the ground with sparse enough supports to be convenient adds a lot of expense. I mainly see it in paid parking lots where the shade can be sold as a value add.
The supports also need to withstand being rammed by drunks in dodge rams.
I think Target and McDonald’s have figured out the solution to that: surround the supports with concrete pillars.
Basically solar panels need structural support.
To cover a parking lot, you must build the supports from scratch. To cover an existing rooftop, the structure’s already there.
It’s slightly more complicated but that’s the basic reason.
I wish, we could at least make parking lots not pitch-black. They absorb so much heat in the sun, which makes them unpleasant to walk across and of course adds to cities being overly hot in general.
Two local shops here have their parking lots out of light gray paving stones, which is so much nicer. I’m guessing, they got forced to pave, so that rain water can drain, which is of course also quite a good idea…
