We need to drastically increase the amount of renewables energy in the world, mainly solar and wind since hydroelectricity is already close to the maximum installed capacity.

I think everyone can agree to that.

The next question is how much and what do we need around it to power a whole country with a minimum of CO2 emissions.

I know about 6 scenarios that has been done for France, if anyone knows about similar scenarios for other countries please share them.

All the scenarios include some degrees of flexibility in the consumption.

To be able to have a stable grid all the scenarios have to include battery storage and thermal production. Today thermal production in the world is mostly gas and coal that are terrible for climate but to have no emissions it will probably be biomass, biogas or hydrogen.

Including a bit of nuclear in the mix (13% nuclear/87% renewable) greatly help to stabilize the grid. This small amount of nuclear divides by 2 the amount of solar needed, divide by 2 the amount of battery storage and reduce by 30% the need for thermal power station compared to a scenario with 0% nuclear and 100% renewables.

There is other scenarios with more nuclear but it shows that nuclear can ease a bit the pressure on renewable energy.

In this case, to replace the last 13% (16GW) of nuclear in the mix we would need to install 90GW of solar + 9GW of thermal power + 13GW of battery.

It shows having a power grid fuelled with renewable energy will become exponentially difficult has it get close to 100%.

There is probably a good ratio between 50%-90% of renewables energy and nuclear energy can be a very good candidate for the rest.

https://rte-futursenergetiques2050.com/panorama/scenarios

[–] Blake@feddit.uk 0 points 1 year ago (2 children)

Most studies suggest that a 100% renewable source of our energy needs is completely viable. That should be our goal. It’s much easier and cheaper to aim for that - what benefit would nuclear give? It’s just much more expensive for all the downsides.

https://en.m.wikipedia.org/wiki/100%25_renewable_energy

[–] BastingChemina 1 points 1 year ago* (last edited 1 year ago) (1 children)

As I said in my comment, yes 100% renewable is possible but adding a bit of nuclear make it easier to achieve and cheaper.

[–] Blake@feddit.uk 0 points 1 year ago

Nope, it will make it harder and more expensive.

[–] Womble@lemmy.world 1 points 1 year ago* (last edited 1 year ago)

given that you are so confident of this can you explain how a 100% intermittant grid deals with a two week dunkleflaute? Im keen to know what the solution is given that storage to cover that for the uk currently (without electrifling transport or heating) would cost in excess of a trillion dollars.

[–] Blake@feddit.uk -1 points 1 year ago (1 children)

To be able to have a stable grid all the scenarios have to include battery storage and thermal production

Totally wrong - you need to source this claim if you’re going to make it. All of the studies I have found claim the opposite - wind power is the best for stabilising a grid both in energy demand and frequency response. With renewables and pumped storage there is no need for batteries or for fossil/nuclear power.

[–] BastingChemina 3 points 1 year ago* (last edited 1 year ago) (1 children)

The source is at the bottom of my comment, you can refer to it. It's only in french unfortunately but nothing an online translator can't help with.

On the other hand you are welcome to provide your sources too.

[–] Blake@feddit.uk 0 points 1 year ago (1 children)

I can’t read French well enough to really dig in to your source and the website doesn’t seem to work for Google translate and it’s too much text to copy/paste, sorry, so I can’t really confirm what you say except the fact that I looked on the site and I saw that they didn’t include pumped storage, which seems extremely foolish. I’m guessing that they were bribed by the nuclear power companies in some way.

[–] pec@sh.itjust.works 1 points 1 year ago* (last edited 1 year ago)

If you go into the detailed explanation (and can read French) they do have some hydraulic pumping included in their "batteries" section.

In their 100% renewables scénario on a peak consumption (105gw) hour and peak energy production (sun at zenith) they would store the excess production like such:

7.2gw to water pumping
22gw to static batteries
2gw back to the grid (chatting electric vehicles I guess).

Also even in their most nuclear scenario (50% nuclear, 50% renewables) they still include 7.2gw of water pumping.

I'm curious of why you put so much value in water pumping? As a Quebecois I have a small notion of how disruptive (flooding of vast areas of land, massive amounts of concrete, dead rivers downstream of the dam ) water reservoirs for hydroelectricity can be and I have a hard time imagining a viable way of relying extensively on that technique.