What remains is solar, wind and nuclear. Environmentalists tend to oppose nuclear (with the exception of Finnish greens) and thus are left with the first two. The thing is, large scale wind and solar are completely unproven. There are two countries that have scaled up clean (CO2 free) energy to meet all of their energy demand in a way that can be applied most other situations; Sweden and France. Both did it with nuclear. Given the severity of the issue of climate change, environmentalists take up a huge burden of proof when they state that renewables can meet all our energy needs.
So far, they haven't proven it. A meta-review [1] of modelled 100% renewable scenarios find that none of them meet a set of basic criteria for reliable energy systems. Another meta-review [2] finds that scenarios without 'dispatchable baseload' such as nuclear and CCS would be much more expensive even if they were feasible. The cheapest scenarios get 40-70% of their energy from nuclear.
There's a basic reason to doubt 100% renewable energy scenario's are infeasible; the intermittency of solar and wind. There will inevitably be days, weeks and even seasons where renewables produce less than required or nearly nothing at all. Unlike the amount of coal, gas or uranium we feed into a power plant, we don't control the sun and wind. There are also periods where renewables produce more than the grid can handle, leading to instability if it isn't used up somehow. Thus, large scale storage is needed. Pumped storage and lithium-ion batteries are not up to the job. Asides from both being extremely expensive, lithium may be in short supply soon and pumped storage has the same environmental concerns as hydroelectricity.
For these reasons the IPCC, IEA and PBL (dutch environmental agency) have all stressed the importance of nuclear in dealing with climate change.
It seems like environmentalists have one last hope; creating fuel with excess renewable energy. Ammonia and hydrogen have been proposed to me as a solution. Besides that, there's the possibility of batteries made out of common minerals like iron rather than lithium. Although the burden of proof is not upon me, I'll be investigating these possibilities in the upcoming month. The basic questions I'll seek to answer are:
- are these options scalable?
- are these options affordable? (read: will climate skeptics take power if this is attempted? (read: what does this do to middle- and lower class energy bills?))
- is there a single modelled scenario or empirical case of these sources providing energy on a large scale?
- do these options have non-CO2 environmental concerns like methane or air pollution?
- are these options safe? (compared to nuclear, gas)
I'll probably make a post about the ecological impacts of the accidents in Fukushima, Three Mile Island and Chernobyl accidents soon.
[1] http://www.sciencedirect.com/science/article/pii/S1364032117304495
[2] http://innovationreform.org/wp-content/uploads/2017/03/EIRP-Deep-Decarb-Lit-Review-Jenkins-Thernstrom-March-2017.pdf