But you can't run the grid on 50% renewables without solving storage. It's just not possible: the grid has to run. Peak usage isn't in the middle of the day, it's around 6-8pm when people are home. In winter that's pitch black, in summer depending where you are there's still very little solar output, so you better hope the wind is blowing. And it is...mostly, but not on demand.

Germany's power grid has started to struggle because they're at 30+% solar capacity, but not reliability - the grid can't sustain losing large swathes of generation capacity suddenly because a cloud passed overhead, or if a region is overcast that day then you've got to make up that shortfall - which you can do so long as you have basically the same installed capacity of gas, coal and oil on standby where they can just turn on an extra-turbine or boiler on demand.

But if you want to actually decarbonize, then you need to solve that problem. Otherwise you end up with the perverse situation that increased renewable investment necessitates new fossil fuel power plants, because you still need to backstop the intermittent sources.

The NSW Australian power grid has this problem right now: the reality is that no one wants to invest in fossil fuel power plants. Great! You'd say. But the grid actually does need a new reliable generator and power price pressure is a big political issue. Getting reliable watt-hours onto the grid - not more intermittents - needs to happen. The catch-22 is people rightly don't want to subsidize more fossil fuels, but the available renewable options are being installed anyway - but they won't solve the actual availability problem we have (and in a country with bush fires it's a big one - 3 months of summer with overcast skies along the east coast from smoke means no one's solar panels were working well, and grid-interconnects have limited capacity).