Sure, they're intermittent which is a downside but they still compete away constant output sources. I didn't mention it in my previous reply but it is possible to vary the output to a certain extend (depending on the technology), the problem is that the economics assume a pretty constant output. This equation doesn't add up in certain places anymore. Therefore I expect that we will have a lot fewer constant output energy sources and a lot more variable energy sources. This will be combined with a certain amount of storage, fossil fuel backup plants, systems to timeshift our energy consumption, probably more usage of district heating/cooling systems and a lot of other stuff of course.