Compared with gas water heaters, the cost of solar water heaters is relatively higher when purchased, but they are much cheaper to run than gas or electric hot water heater.
If in your area, the number of sunny days is the vast majority of the year, it is more cost-effective to use solar water heaters. Meanwhile, electric heating can be used as a backup heating for a few rainy days.
The exact cost of running a hot water system depends on the location, climate, and energy prices. As solar water heaters become more intelligent and user-friendly, they are favored by more and more regions and people.