by Erwyn | 2025-09-13 11:45:10+00:00
> in theory any amount of power a nuclear plant would generate could also be achieved with large amounts of renewables no?

Yes in theory, the problem is when you try to apply theory to practice: I don’t want to make a disservice to this discussion and as I don’t have the figures at hand anymore but there have been thought experiments around this and one was to hypothetically have two dams that would pump 2 meters of water out of the sea between France and UK and then release it. If my memory serves well this would only cover 1 week of France’s energy consumption.

Okay, appart from the fact that you would require far more space in term of infrastructure for renewables, the most interesting issue with renewable energies for me is that they are not controllable (I don’t know if this is the correct term in English): basically you cannot command WHEN you produce energy, you are dependent on weather (sun/wind) or water current (tidal power).

What that means is that you cannot aling production with supply and you end up in some cases with acute mismatch: for instance in France, the peak of energy consumption is during winter, a time where there is very few sun, while Japans peak is in summer which could be more convenient.

The Rule when dealing with energy production is that you can’t produce less than demand nor more than demand otherwise you end up with a blackout and potential damages.

To mitigate both the rule of energy production and the non controllable aspects of renewable there are strategies. The two most common ones are buying/selling your energy and storing/unloading it. Those work but they do have their own pitfalls. Buying/selling for instance does work for adjustments but not for peaks because usually during peaks your neighbours are also peaking and thus also looking for selling.

Storing/unloading is its whole set of problems making it hard. You will find a lot of documentation on the subject but here is the gist of it: fist of all it is inefficient meaning you need to produce far more energy than you store and are able to unload in the end. Storing in batteries takes a lot (like really a lot) of place and we are talking nation wide production. Storing using a dam (pumped storage power plants) which is quite a nice way of doing it requires to have places to build them, meaning the correct geographical circumstances. In France for instance we already have quite a large dam network and couldn’t really build more (added to the fact that you usually need to flood a valley which gerenally is not well taken by the inhabitants of the place).

So here you are with your whole lot of space used up to produce renewable energy but you are still confronted to the issue of its non controllable nature. Sure you can store/unload a bit, you can buy/sell another bit, but in the end you still have to face the fact that it is not controllable. So how do you solve the issue ?

Here comes your friend, the controllable energy. A solution to your issue, and the one which is basically always applied is to have a mix of energies, meaning adding a controllable one along your non controllable ones to make up for the highs and lows of the latest. And the king of eco-friendly controllable energies is a nuclear power plant, not only because of the ecological factor but also because of the ratio space/energy produced.