The only reason is cheap electric prices for big corps. If they wouldn't get subsidiaries, i bet you there is solar everywhere. Also a lot of them started doing this in the eu but there are not enough installation professionals to keep up.

You've fallen for the myth of corporate efficiency.

Solar panels are a classic "it takes money to make money" example. Pretty expensive up front. I feel like that's the main reason.

1/3 of the warehouses in my area have solar panels.

The main factor to stick with grid power, I assume, is the electricity is cheap enough. Panels take a decade or more to pay back in savings. Many tenants won't stay that long. Many landlords won't give a shit with directly billing the tenant. Even as an individual homeowner, 10 years is a long way away.

A second angle that's a relatively recent thing here is my utility no longer allows you to connect oversized solar systems to the grid. Annual production must match annual consumption. I'm not exactly sure how that plays out on the corporate level, as my experience is individual. Even though it gets hot here, many warehouses are not air conditioned. Without AC, energy consumption for a warehouse is way below the available solar space. So, many warehouses are only half or 1/3 covered, of those 1/3 or less warehouses that have any solar at all. Nobody wants to sublet their roof to the electric company, so the space remains unused.

Meanwhile, I'd expect mall and especially office consumption to exceed rooftop production capability, so solar is only worth the little green leaf stick you can put on the front door saying "we went solar!". Somewhat similarly to not wanting to rent space to the utility on a warehouse, these places would need to be incentivised beyond net-zero cost to do some social benefitting on their property.

The utility company says they're going green, but in reality, they're taking credit for private home solar installations. The kwh price keeps going up. They keep telling me switching to LEDs and unplugging chargers will make it better.