Why transport energy from far away via expensive cables when you can just put some cheap solar panels right next to where they are needed?

The dirty little secret is that there is little payback for retailers to do so.

Walmart could do it at scale, but they already can put megawatts of solar on existing roofs for their stores. Article mentions several states where solar is discouraged to protect monopolies. Not to mention another article out saying Republican-led states are actively punishing corporations who reduce their emissions. Walmart isn’t going to see a realistic payback from that investment, and could even face backlash. They also sometimes get tax credits and incentives from the power company to build a Supercenter in a certain area. They do however buy into solar farms to offset their carbon.

Other retailers (Trader Joe’s or Starbucks) it wouldn’t make sense for, most lease their buildings and don’t have enough expertise to take this on. Commercial property owners wouldn’t care about this.

I think your point is very important. Stakeholders other than the owners (eg. Renters at apartments, condo owners within an HOA, companies that lease office space, etc) want at least some of the benefits of solar, but don’t have enough clout to do it.

Some states in the USA have a “community solar” project concept where you can invest in a solar project and the power it generates can directly credit your electric bill (basically decoupling location from solar ownership). I just wish it worked better and more people were investing in it.

Walmart has solar panels over its parking lot, here.

If the parking lot and building belong to the developer, they can put up the solar farm. Besides pocketing the extra revenue, they can attract better tenants or offer better prices than the competition.

Walmart in fact has solar installations on many of its store roofs and has been putting them there for years.

Because the cost of the panels is a shrinking part of the cost of a solar installation, but the work of the contractors is cheaper when you don't have to install them at a height where cars can fit under them.

Transmission losses might only be 5%. You can make up for that by putting panels in sunnier locations (Mojave desert vs SF) at better angles and with economies of scale. A homeowner with rooftop solar will spend more servicing panels than a large scale operator.

Desert is a dumb place for a solar farm. Far from users, damn hot, and collect dust.

Farm fields, pastures, canals, lakes, and reservoirs are smart places for solar.