From the academic literature:
A key problem with solar energy is intermittency: solar generators produce only when the sun is shining, adding to social costs and requiring electricity system operators to reoptimize key decisions. We develop a method to quantify the economic value of large-scale renewable energy. We estimate the model for southeastern Arizona. Not accounting for offset carbon dioxide, we find social costs of $138.40 per megawatt hour for 20 percent solar generation, of which unforecastable intermittency accounts for $6.10 and intermittency overall for $46.00. With solar installation costs of $1.52 per watt and carbon dioxide social costs of $39.00 per ton, 20 percent solar would be welfare neutral.
20 percent being the social welfare breakpoint for solar in Arizona will not strike anyone as especially notable, but of course the infrastructure integration technologies may improve. In gross terms, carbon costs are exceeded by intermittency costs. Also, forecastable intermittency accounts for most of the prices, and so with storage, that is perfect solar would be a technology that is much more efficient.