And that on-roof-solar helps (as it becomes widespread) mitigate the growing need for additional grid capacity. Canada is a big country and, outside the major cities, upgrading grid capacity is quite expensive per capita. It's a win-win in Canada, investing in self-sufficiency while reducing the maintenance burden of infrastructure.
It may slightly help with capacity, but it causes bigger problems financially. Even if a home uses next to no power, it still must be connected to the grid. The total number of such homes ends up meaning a lot of power lines, transformer stations, monitoring equipment, and people to do all the work.
If you have all of that expense, and suddenly people have solar panels so pay $0 for an energy bill - do you see the problem? The actual cost of fuel/generation is very small compared to the fixed costs.
The more people use solar, the more in the red the utility becomes. You can 'fix' this by making it so every home has a fixed 'connection cost' and then a smaller 'usage cost' on top, but that destroys the incentive for solar panels - they'd never break even for the average buyer.
Solar is great, fantastic even. But it should be done centrally, or people will have to get used to the idea that they will never pay themselves off and are just doing it for the environment.
Where I from, every utility bill has two parts: fixed cost and metered cost. You pay for installed capacity and by the meter for actually consumed kWh, GJ, m3.
It's not a legal problem. The reality is that the vast majority of homes with solar must be connected to the grid because that's how they're wired and designed. You can do a completely off-grid approach, but it's more expensive and requires large batteries. Most people just do the simple panels and don't have any intention of going off-grid.
Also: Even if half of a neighborhood doesn't need the connection, the work ends up being similar. It's more based on distance/area.
If there is no in-house storage to match, how does it help the grid? It is still needed for cold winter nights, where demand is high and solar panels produce nothing. Hydro can provide the power, but the grid will be running at full load.
Most houses in Canada are heated with natural gas. I'm not negating your overall comment, but in general, cold nights don't strain the grid because of heating needs.
(still good news, as most of Canada's electric generation is low carbon hydro, and the rest of fossil generation can be pushed out with storage and renewables, although I do not have a link handy by province how much fossil generation needs to be pushed out)
I live in New England. We do not have enough natural gas pipeline capacity to meet demand in long periods of very cold weather, and have very limited natural gas storage that can't buffer that for as long as a cold spell can last.
In these periods of time the grid traditionally keeps the lights on by switching over a significant portion of the grid to burning oil for power, and/or with the occasional LNG tanker load into Everett MA. These are both....pretty terrible and expensive solutions.
Burning less natural gas during the day still helps at night/at peak, because it means there's been less draw-down of our limited storage/more refill of it during the day, so we don't have to turn to worse options as heavily at night.
I think the inverse has proven to be largely true. If a home that uses effectively net-zero power is still connected the grid, it becomes a liability to grid stablity and expense.
There still needs to be enough power to supply to all those homes in the event of a protracted time where solar is unavailable. It gets less applicable as homes start to get multi-day battery banks installed, but those are incredibly rare since they are too expensive.
The whole "wealthy homeowners get subsidized solar and then effectively free backup power paid for by everyone else" needs to end.
