So... how do you feel about apps[0] that let you automate pushing electricity to the grid from your own home battery based on wholesale electricity prices?

Nothing could possibly go wrong?!?...

[0] https://www.amber.com.au/

Unfortunately this isn’t possible. If we spent billions upgrading electricity infrastructure, sure. But it’s much cheaper overall to make smart use of solar panels and batteries that are already being installed in the grid. And that requires a smart grid, full of networked equipment.

For example, during peak sunlight times, many neighbourhoods now generate more solar than they use. Without a sink for that power, voltages would go haywire on power lines and damage equipment. So the grid uses control boxes to manage how much power each house is allowed to send back to the grid. And all that needs compute, live metering and so on.

You can do a one way link, sensors on infrastructure which emit data only but can not receive anything. Then another device like an ESP32 or whatever the industrial version is which reads the data and makes it available to the internet.

You now have the ability to remotely monitor the system but hacking it does not allow you to control anything. Though there is still a sizable amount of infrastructure which has no on site workers and needs to be remotely controlled.

There is plenty of room for antiquated process and technology in utilities that has nothing to do with grid operations, trust me. :)

Air-gapping is a start.

Critical National Infrastructure should go further, as Iran found out with Stuxnet.