Academic solutions are focused on what's theoretically possible. They rely on technically plausible but unproven technologies that need decades of development to prove political, technical and economic viability at scale. A previous example of an academic solution was the Hydrogen Economy. This attracted significant investment but never gained traction because of multiple political, economic and technical issues.
Here is a quote from a recent 100% renewables paper about solutions to long duration intermittency of renewables:
“In the first scenario, during periods of extreme weather or when wind and solar energy fail or fall short, Brown and his team suggest imports, hydroelectricity, batteries and other storage methods. Or, in the " worst-case solution," they said hydrogen or synthetic gas produced with renewable electricity could fill that gap. As for maintaining grid stability, they offered technical solutions, such as rotating grid stabilizers and newer electronics-based solutions.”
All of these “solutions” to long term intermittency face severe obstacles. For example, imports relies on long distance transmission. The reality is there is very little long distance transmission in the world today so current transmission is not a good reference to what is needed. At distances that would work to provide electricity from a geography not suffering the intermittency, transmission cost would be higher than generation cost. There would also have to be excess generation to provide the needed long distance electricity. Already this would triple the cost of backup electricity. The amount of transmission lines would have to be sufficient to provide for a large geographic region. Transmission lines are politically difficult to get approved. The transmission and excess generation would have a low utilization factor which would further increase its cost.
All of these problems are economic and political and not related to technological feasibility which is what academic solutions focus on. Solutions like hydroelectricity suffer from a lack of rivers to dam and a political resistance to large hydro. Batteries are expensive and short lived and need technological development which is occuring at a slow pace. Alternative storage, like compressed air have failed to gain traction. The “worst case solution” of hydrogen from electrolysis suffers from a lack of development at scale and the fundamental low round trip efficiency and low utilization factor of the electrolyzer and generation plants. To make hydrogen work requires new technological development and renewable generation to be very low cost.
Viewed objectively, proposals for 100% renewable solutions are all at least as speculative as Stratosolar. Stratosolar risks are in the feasibility of assembling and deploying its large structures which can be proven in a short time frame without a large investment in a supporting infrastructure or a large political consensus. Given the desire for 100% renewable solutions and the problems with all the proposals, it is difficult to understand the lack of interest in a plausible solution.
By Edmund Kelly