At least the last TGB was due to unusually cold weather, bad preparation for frozen gas pipes etc. If the "renewables" contributed anything, from what I remember, it would be perhaps a rounding error.
Solar and wind is not as reliable as a coal fired plant but you also don't have to continuously supply coal and it is not that bad as you would imagine either. Yes, it demands more planing, sensors detecting the conditions a good grid, perhaps some short term storage and longer term demand/ production adjustments. The great thing is, you can shut of a solar or wind power plant in probably minutes and it costs you nearly nothing (besides lost opportunity). Try that with a coal fired plant or nuclear power plant. You can also build solar and wind in places, where you wouldn't want a coal fired or nuclear power plant.
From what I can see, solar and wind seems to be the more economical way overall. It isn't perfect now and we have to have other sources in the mix but longer term I don't really see a reason, why most of the planet couldn't use solar, wind, water dams, geothermal etc. with some sort of smart energy storage or better demand/ production shaping for most of our energy needs, especially if we end up paying less for the same service level.