[strawhatguy]

Something has to cover renewable’s shortfalls when the sun doesn’t shine and the wind doesn’t blow.

In Texas and Germany now, it has shown that over reliance on them have led to more instability in the grid, leading to higher fossil fuels use.

Basically you can’t really have renewables without nuclear to back it. They’re a package deal. I don’t know where this renewable purity comes from, but it’s not helpful.

[Gwypaas]

> B. Dealing With Variability and Stability

> Much of the resistance towards 100% RE systems in the literature seems to come from the a-priori assumption that an energy system based on solar and wind is impossible since these energy sources are variable. Critics of 100% RE systems like to contrast solar and wind with ’firm’ energy sources like nuclear and fossil fuels (often combined with CCS) that bring their own storage. This is the key point made in some already mentioned reactions, such as those by Clack et al. [225], Trainer [226], Heard et al. [227] Jenkins et al. [228], and Caldeira et al. [275], [276]. However, while it is true that keeping a system with variable sources stable is more complex, a range of strategies can be employed that are often ignored or underutilized in critical studies: oversizing solar and wind capacities; strengthening interconnections [68], [82], [132], [143], [277], [278]; demand response [279], [172], e.g. smart electric vehicles charging using delayed charging or delivering energy back to the electricity grid via vehicle-to-grid [181], [280]–[282]; storage [40]–[43], [46], [83], [140], [142], such as stationary batteries; sector coupling [16], [39], [90]–[92], [97], [132], [216], e.g. optimizing the interaction between electricity, heat, transport, and industry; power-to-X [39], [106], [134], [176], e.g. producing hydrogen at moments when there is abundant energy; et cetera. Using all these strategies effectively to mitigate variability is where much of the cutting-edge development of 100% RE scenarios takes place.

> With every iteration in the research and with every technological breakthrough in these areas, 100% RE systems become increasingly viable. Even former critics must admit that adding e-fuels through PtX makes 100% RE possible at costs similar to fossil fuels. These critics are still questioning whether 100% RE is the cheapest solution but no longer claim it would be unfeasible or prohibitively expensive. Variability, especially short term, has many mitigation options, and energy system studies are increasingly capturing these in their 100% RE scenarios.

https://ieeexplore.ieee.org/document/9837910

[strawhatguy]

Yes, it’s fairly obvious that one would have to oversize capacity, etc. to get to renewable purity.

But note this is all hand-wavy future talk, whereas in the here and now, the over reliance has led to higher fossil fuel use.

It’s like language design, where language features could be thought of free with a ‘sufficiently smart compiler’.

In theory, yes 100% renewable is possible. In theory, theory and practice are the same. In practice… not so much.

abandoning (or at least ignoring) an energy dense and emission free energy source as nuclear is a setup for failure, as has already been seen twice in the past couple years.

[pfdietz]

> But note this is all hand-wavy future talk, whereas in the here and now, the over reliance has led to higher fossil fuel use.

I don't see how this claim could make any sense. Are you saying that if we didn't have renewables, we'd be using less fossil fuels? How could that be? In the US, nuclear construction flatlined long before wind and solar came along. Were renewables not coming on now, the alternative would be fossil fuels, and in particular natural gas. Elsewhere, coal would have been the alternative.

Perhaps you're saying that IF CO2 charges were added, nuclear would have been favored. But with CO2 charges, renewables are also favored, and likely dominate at a lower CO2 charge level than would be required for nuclear. Getting the last bit of generation fully defossilized on a nuclear grid would require truly enormous CO2 taxes, perhaps as much as $1000/tonne.