You didn’t seem te read the parent’s comment fully.

What he suggested is that we use the overprovisioning to generate methane or hydrogen so it propells us through a few weeks of no wind or sun.

So, instead of 1GW of Nuclear you have 2GW of solar/wind + 1GW electrolysis and 1GW of hydrogen capacity.

This gives you better network stability than nuclear and the cost are or will soon be lower than the nuclear

What is the efficiency loss at each of these steps to get methane/hydrogen, and then the efficiency loss to convert these materials back to electricity?

I have no issue with using renewables per se; I'm just skeptical about basing the entire system on them:

* https://en.wikipedia.org/wiki/Capacity_factor

And what's the leakage rate during production, transportation and combustion? Methane is 80x more potent than co2.

> When there is zero wind and zero sun then it doesn't matter how much over provisioning there is: your output will be zero.

That does not really happen over large geographic regions, within which one can distribute energy via the electrical grid. In Germany, there has been a lot of research put into that before the non-nuclear strategy was decided. It was a political decision, but it has been prepared by many, many engineers and researchers.

In fact, there are times where Germany exports needed energy to France, in spite of that France has much more nuclear power. Sometimes that happens in hot sommers, when rivers have to little water and they become hot. Then, nuclear plants need to be shut down because otherwise they would cause environmental damage.

Other times, it happens in winter, because a lot of heating in France is electrical to accomodate for nuclear energy. But sometimes there is a shortfall, and it turns out that on windy winter days there is an excess of wind energy in western and northern Europe.

Another thing, storing energy is not necessarily expensive. A lot of energy use is things like room heating, room cooling, or hot water. Now, heat can be stored efficiently for many hours. (In larger tanks or earth installations, it can even be stored efficiently for months).

There are times when Germany exports energy to France, and those are hugely popularized due to the reasons you stated. However, the far more frequent cases are: Germany has excess transient wind or solar energy, even making energy prices negative sometimes (due to fixed guaranteed producer prices and guaranteed preference). Energy storage companies in neighboring countries, mostly pumped hydro in the alps and Norway, buy the excess power and sell it back when there is demand (of course with an appropriately large margin).

In general, Germany has not planned for and refuses to build any significant kind of energy storage. Existing pumped hydro plants are even shut down. Transmission lines to even out the regional differences due to weather and consumption are planned, but do not exist yet for the usual reasons and will not exist for the next decade or so. This means that Germany relies on the rest of the European grid to balance out its excess production or consumption phases, of course at a significant cost in stability and money. Cherry-picking times where the balancing-out causes energy exports to France is just propaganda imho.

At least in the US this was supposed to be solved by interconnecting the three major grids, since it's highly unlikely that there would be zero wind and solar across the entire continental US all at once.

How connected are grids in Canada?

Canada is connected inside itself and to the US:

* https://en.wikipedia.org/wiki/North_American_power_transmiss...

Ontario specifically is part of the NPCC:

* https://en.wikipedia.org/wiki/Northeast_Power_Coordinating_C...

It connects to Michigan, NY in two places, and Quebec in a few.

Energy storage is cheap. Underground air pressure, mine-shaft gravitational, hydro-dam gravitational, molten salt, LH2, they all work.