People are focusing on sustainability and climate change too much. It's a nice side effect of people shifting to renewable energy. But the real story here is the economics and wiping out marginal cost of producing energy. Most infrastructure related to renewable energy has cap-ex but very low op-ex. Once you have it, it works for decades.
And the cap-ex part is coming down steadily due to economies of scale, learning effects, R&D delivering incremental improvements, and of course occasionally some bigger improvements.
This is often portrayed as cost that somebody needs to pay for. But a better way to think of this stuff is as investment with a big return on investment. Op-ex has no ROI. If you buy fuel, you burn it and then it's gone. Cap-ex can have lots of ROI. A battery that removes the need for you to source many gwh of power over a few decades is saving you money. If that energy is surplus solar/wind with essentially very low marginal cost that would otherwise have been curtailed, you save money. That's why pairing solar with batteries is so popular. It increases the capex. But you get better utilization of your solar panels.
So, these grid improvements might potentially have a really good ROI for Canada. Grid infrastructure lasts a long time; especially power lines. And they move a lot of power around. Which is nice when you have a lot of very spikey supply from solar and wind. This often results in over supply, which then gets curtailed (thrown away). If the grid can move it to somewhere it can be used, that can offset other energy sources (e.g. gas power) with higher marginal cost. This 50 billion amortizes over decades but might break even before the first decade is over.
that's also why i don't understand why germany is financing it through the electricity prices.
it's a classic investment for the bond markets.
the oldest of the huge poles for high-voltage power lines here in germany is 114y old.
now that's roi in excellence.