The author is vastly underestimating the problem caused by intermittency. He just slap $600 of batteries and consider it not intermittent anymore.

It's way more complicated than that.

First is the batteries, how much batteries? Enough to cover the night, one cloudy day, two ?

Then what do you do about winter ? Solar is producing 2-3 times more in summer than in winter, however we use generally not electricity in winter. So do we oversized the solar installation so it still producing enough for winter or do we plan backups ? What kind of backups? We have hydroelectricity and wood, but again if we need to build more wood burning power station it has a cost. Same thing with oversizing the solar installation.

I'm not saying that against renewables energy, I definitely the way to go.

However saying that a kWh of solar/wind is xxx cheaper is misleading.

Yes it's true that producing a kWh of renewable energy is cheap, however producing a kWh of renewable energy when we need it is way more expensive and it needs to be taken into consideration!