There's an interesting article in Nature that discusses the limits on wind and solar. (Here's a link.)
If future net-zero emissions energy systems rely heavily on solar and wind resources, spatial and temporal mismatches between resource availability and electricity demand may challenge system reliability. Using 39 years of hourly reanalysis data (1980–2018), we analyze the ability of solar and wind resources to meet electricity demand in 42 countries, varying the hypothetical scale and mix of renewable generation as well as energy storage capacity. Assuming perfect transmission and annual generation equal to annual demand, but no energy storage, we find the most reliable renewable electricity systems are wind-heavy and satisfy countries’ electricity demand in 72–91% of hours (83–94% by adding 12 h of storage). Yet even in systems which meet >90% of demand, hundreds of hours of unmet demand may occur annually. Our analysis helps quantify the power, energy, and utilization rates of additional energy storage, demand management, or curtailment, as well as the benefits of regional aggregation.
I live in an area (northeast ohio) with lots of cloudy days per year--200 according to this chart! Many of those days, especially in the winter months, will be very dark and solar panels won't produce much power. Plus in the winter, we can get heavy snows. In short, several days per year won't be conducive for solar power production.
If I wanted a reliable solar energy system for my house, I'd have to massively oversize the batteries and the panels. The cost gets prohibitive really quickly. Utility companies will have to do the same thing.
Anyway, it's going to be difficult and expensive to "transition" from fossil fuels to wind and solar if it's possible at all.