These technologies exist today and are based on sound thermodynamic principles and existing industrial capability.
I'd say if we could provision 1 hour's worth of storage over the span of a decade, that'd amount to a demonstration of economic feasibility. But few of these upcoming technologies are making it out of the prototyping stage, let alone commerical success on this scale.
No one is presently making these because the policy of the grid was developed around power plants that dig stuff out of the ground and burn it - the markets are based on bidding with the assumption every power plant will have a marginal cost of generation relative to the cost of its fuel. This policy doesn't reflect the nature of renewables which besides their capital cost have very low to 0 marginal cost of production. This has disrupted the energy markets in many ways and policy is still being developed to incentivize storage capacity.
You can listen to the people who work in this industry and have studied it deeply or you can keep googling furiously for webpages that support your magical thinking.
In fact, I didn't see ANY links from you supporting your nonsense about renewables not working, despite them working in many places across the globe.
>literally none of these are currently capable of replacing baseload nuclear and fossil fuel energy generation.
Literally STORAGE will never replace GENERATION, they are two different concepts which most people understand but you apparently don't. STORAGE can supplement INTERMITTENT GENERATION to create DISPATCHABLE GENERATION for far cheaper than nuclear plants.
It'd probably be helpful to elaborate, rather than just insist that the above commenter is wrong and loosely suggest at other solutions.
Things like hydrogen storage, synthetic methane, and thermal storage remain in the prototyping phase. I think it's not correct to say that they can, seeing as there isn't even a commercial market for these technologies let alone one that we know will scale. By comparison countries have already powered >80% of their electricity with nuclear.
It's clear than nuclear power can completely replace fossil fuels. Renewables might be able to replace it, but that's a gamble based on assuming a new storage solution will work excellent. Not just better, but truly blows-everything-else-out-of-the-water phenomenal. When the stakes at play are stopping climate change, this is a very risky assumption to make.