We are in the midst of a badly-needed transition from greenhouse-gas-emitting generation technologies to renewable technologies. The speed at which we make this transition will determine the severity of climate-change environmental impacts for the next few decades. So far, we have done a pretty good job of developing additional renewable technologies and driving down their cost and (especially) the cost of the (mostly electric) energy they produce.
But what does the title have to do with the title of this paper. There are a wide range of renewable technologies, and some of those are very mature, some are immature, and all continue to mature at varying rates. In order to better understand how we (our economy) should allocate our resources I believe that need to do a bit of parsing of these technologies and their maturity. Let’s start with the latter.