They do not need to know what generates there electricity but...

- when what generates the power changes the landscape they can see, many people get upset, however irrationally

- many people are emotionally attached to lifestyle objects that use fossil fuels, i.e. cars, boats, planes, etc

- even where there are good options, most people are not willing to spend one extra penny

- even when there are options that cost less (i.e. bicycles, walking) humans spend a lot of their energy thinking about status and struggle to voluntarily choose things that they fear might result in a loss of status

- even if you solve all that, collective action problems are a named thing for a reason - they are hard and don't necessarily have obvious answers.

My point is not that everything is hopeless, but that OP who said "Have we ever as a species successfully changed our behavior on a scale..." has a point that we will have to grapple with if we want to actually change stuff. Wishing human nature away doesn't actually solve anything.