There are numerous studies that predict that intermittent renewables become less effective as their penetration increases. This is mainly due to reduced capacity factors as intermittent generation is curtailed when its generation is not needed. An equally significant factor is that fossil generation capacity is also curtailed when intermittent sources are generating. The system as a whole has an increasingly reduced capacity factor as intermittent generation becomes a larger percentage. Capital cost and fixed O&M costs are the biggest costs of generation. Lower capacity factor increases the cost of generation proportionally. As Michael points out, there is now evidence that this actually occurs.
As we have discussed endlessly, a solar based solution needs to 1) be much cheaper, 2) not have random intermittency and 3) have a cost effective storage solution for night time generation. Current solutions do not satisfy ANY of these criteria and cannot succeed. It seems that current wind and solar must fail before there is acceptance that these requirements apply.
Stratosolar does meet these criteria.
By Edmund Kelly