What hydrogen does is provide a way to store energy for long periods of time much more cheaply than batteries. The cost of hydrogen storage capacity underground is maybe $1/kWh. Of course the round trip efficiency is much lower than batteries, but for long term storage (or when the input energy becomes very cheap) that doesn't matter as much.
The latter makes the former worse (because we lose some of that energy in the storage process).
The truth is that we need a mix of nuclear, renewable, and a ton of sobriety because after fossil fuels we will just live in a world with a lot less energy. And I don't think we can afford ignoring nuclear power.
BTW, just compare France and Germany. It seems pretty obvious that the french model (with nuclear power) works a lot better.
Basically, you're complaining that CO2 pollution isn't going away on its own, and that's the fault of anyone but the polluters. No, it's the fault of laws that allow the polluters to impose their negative externalities on everyone else.
No, we don't need "a mix of nuclear, renewable". There doesn't appear to be any good place for nuclear in a future energy system of cheap renewables. There are all sorts of ludicrous energy sources we won't be using, and one cannot just presume nuclear is not also in that set.
Of course it is not. But with nuclear + renewables, we are still heading towards a world without e.g. aviation because we won't have enough energy for all those planes we fly today.
Everything will be more complicated, and we can't afford to be picky with the low-carbon energy sources. Going with nuclear and renewables is infinitely better than what we are doing now (which is... going towards a catastrophe).
Even assuming we want to increase the world average from the current (roughly) 2.3 kW to average consumption of the single most intense nation (Qatar, at roughly 23 kW) while also using 20% cells, this is still less than 1% of the surface of the planet — for comparison, about 4% of the US land area is "urban", and a further 21% is cropland, and 35% is pastures and ranges.
We love to speak about "potential" and extrapolate given current numbers. But the fact is that we have never done anything like that at scale. We do not know if we are capable of replacing fossil fuels. It's not just a "potential", it's really an engineering problem. The devil is in the details.
And when you start looking at what would need to change to run fully on electricity... you realize it won't fully replace fossil fuels. Not even remotely.
Not a single nuclear reactor today has been produced fully with nuclear energy.
But this is a ridiculous constraint, since it says the entire problem has to be solved in one shot.
Which I did not claim at all. I keep saying that we need both nuclear and renewables, and you keep opposing renewables to nuclear. We won't go anywhere, let's stop here.
From the analysis I've seen, nuclear has no place. It's simply too expensive and constrained.
Irrelevant, and also probably false on a technicality.
All those things can be powered by renewables, each sub-component demonstrated, the question is cost and what scale at which they have been built so far.
> We love to speak about "potential" and extrapolate given current numbers. But the fact is that we have never done anything like that at scale.
Only if you ignore all the things which form the very industrial base we want to update.
> And when you start looking at what would need to change to run fully on electricity... you realize it won't fully replace fossil fuels. Not even remotely.
If that were true, we all die miserably (in the next 40 or so years as the things driving the last century of fossil fuel use imply an exponential growth pattern) while being painfully stupid thanks to the fact CO2 in the air impedes human cognitive capacity.
(And nuclear won't help because your claim was "electricity" not "renewables").
Fortunately, roughly half of our total (20 TW) final energy consumption is "make things hot", which is very easy to electrify — given the way I use words, I think this by itself would be enough to disprove your "not even remotely" all by itself.
A further 3 TW is transport, of which 0.3 TW is spent on each of aviation (short-haul flights can be electrified, only longer distance ones are currently hard), and marine fuels. The rest is all stuff which can easily take batteries or hydrogen.
There's some overlap here with the 2 TW of electricity, but that means I've shown somewhere between 70% and 80% the energy use problems are easy.
What's harder is that I just said "energy" not "carbon", because some of what we do releases CO2 or other greenhouse gases without being related to energy use. Fortunately there are plenty of people working on solutions to the problems with cement, cattle, and metal oxide reduction — but they're not a correct part of the framing for energy specifically, even though they're totally relevant for the environment as a whole. Likewise the use of hydrocarbons as chemical feedstocks for plastic: very important when we care about running out of oil, not a big issue when we care about CO2 emissions.
There's no reason to think that's true. I will add that the carbon in waste streams in the US is more than enough to provide current US consumption of jet fuel (with hydrogen added so all the carbon ends up in the fuel, not going into CO2).
There are several paths, they just need to be walked.
Gas is a known method to spread heat and electricity, hydrogen is a gas that is entirely downside-free from a eco-fuel perspective. We can burn as much of it as we want 24/7 and we can make it from sunshine and seawater, returning the water in the process.
A 6-lane highway to perfect stability right there.