The pricing problem sounds like an artifact of how you've structured the market, not a fundamental obstacle to the profitability of intermittent power sources.

An alternative structure that would solve the problem would be for generation operators to buy put options for energy they expect to be able to produce, eliminating the risk of a price collapse. Consumers who want access to such intermittent energy would have to write those put options, which would be limited to particular times on particular days when they could use the energy. Having written the option, they would have to accept the generation operator's decision whether or not to exercise it. Utility-scale storage providers could write puts for low-demand times and buy puts for high-demand times, or they could write puts for low-demand times, write futures contracts for high-demand times, and make up the shortfall on the spot market. This might produce major changes in consumption patterns, but, more likely, would enable continued investment to minimize those changes.