Brisbane

I wonder if it could be as simple as that, as just having the houses only supply, as the grid needs it, with something as simple as a regulator?

It comes down to what system you have, all solar panels are the same, they generate DC power in the sun, and send it down the line to the next set of components, for an off grid set up it usually goes, solar controler, this let's the right amount of watts through to supply current demand and/or charge the batteries, from there depending on the set up either to the battery's detectly or through the inverter to the battery's, the inverter takes DC and turns it to AC to run whatever is at the end. For on grid the panels run to an inverter that powers either the current demand or pumps the power being made by the panels to the grid, this is where you can run into trouble if everyone has just on grid setup, if no one's using power at midday then you have all that power being pumped into the grid and it puts a fair load on things to keep it from poping. There are hybrid systems as well both the panels and grid run to the batteries.

I personally think if each house had a battery system, connected to the grid that also has a battery bank say at every transformer on a pole, I think that would make a pretty good multiple redundancy grid, expensive sure, but how much money does the government already waste. Just my 2 cents