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Comment by melling | Hacker News Reader

“Co2 emissions from electricity generation account for 45% of world energy-related emissions.”

We’ve been talking about climate change for 3 decades now.

I wonder how much time we could have bought ourselves if we had immediately embraced nuclear power

Honestly quite a bit, but, unfortunately the response time of Nuclear power is not the fastest available. It takes hours to get the process going, or to shut it down, and unfortunately an energy grid needs to have a demand-supply net of 0 (usually plus/minus 1.5%) or the appliances connected might face some irreversible damage. This means that, while Nuclear could have been a great answer to a good chunk of the energy demand (sorry cannot estimate how much), we would have probably still needed a lot of the traditional fossil fuel source fo generation.

The other aspect to always keep in mind, when looking at a system as mature as the energy grid is COSTS. Most likely the economy of nuclear doesn't work out compared to the alternatives available. (that's why policies and incentives are needed to move away from fossile fuel)

When you try to dismiss nuclear, what alternative "clean energy" can you "turn on" when experiencing increased demand in energy? Can you turn on the sun or the wind?

There are two aspects to consider here:

1- what is the response time and the cost for alternative generation: Biomass is a valid 'on demand' alternative here. Geothermal + Tidal, while still intermittent are more predictable (like the Sun) hence it's easier to design ahead. Which is quite useful when it comes to deployment You can read more here: https://courses.edx.org/assets/courseware/v1/95ea4a6731bff7e...

2- what other demand-respond can be achieved/deployed (i.e.: storage and demand side response). For instance hydro is a very good solutions here, malten salt storage, and hydrogen are upcoming technologies. More on flexibility here: https://courses.edx.org/assets/courseware/v1/416cc82fc233d20...

In 2019, just about 10 % of the global electricity came from nuclear power. Hence replacing fossil sources by nuclear would entail large-scale construction of new nuclear reactors. However, we then run into the problem of peak Uranium (our reserves are thought to last for about 140 years at the current rate, but this would shorten to about 14 years if we increased nuclear by a factor of ten). (New kinds of reactors might alleviate this problem, but they are not actually available now. Of course, they might be if, as you suggest, we started on this course earlier.)

In any case, nuclear power is today not economically viable -- wind and solar are cheaper by a factor of 2 to 3 (computed over the full lifecycle, but excluding the indefinite storage costs of nuclear waste).

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