Archive:000/Decarbonize the energy supply

How to produce enough energy (for the world) without burning fossil fuels?

Ongoing challenges

The renewables approach (+ energy storage)

• Solar & wind power would have to be the main sources, because other renewables are limited to very specific geographic regions.
• Most solar panels today would probably be unsustainable or even impossible to scale up, due to having too many scarce minerals in them.
  • See discussion on alternatives to this.
• Batteries might be scalable enough to smooth out the day/night cycle of solar. (...)( Best bet would be either sodium-ion or iron redox flow batteries. )
  • But the seasonal fluctuations of wind & solar probably need far more energy storage capacity.
    • See discussion on other energy storage types and whether any could provide enough capacity.

More discussions:

• Is there enough land to scale up wind power (without causing significant ecological damage)?

The nuclear approach

Considering the different types of nuclear power, it seems that thorium power is the one with the least problems. Here's a comparison:

Type of nuclear power	Problems if scaled up
	Fuel scarcity	Weapons proliferation	Nuclear waste
Conventional nuclear power (status quo)	Problem	Low risk	Problem
Conventional small nuclear reactors	Problem	High risk	Problem
Uranium-238 breeder reactors iAdditional benefit: Uranium-238 reactors would make use of existing nuclear waste, which has been left over from decades of conventional nuclear power.	Abundant	High risk	Almost none
Thorium-232 breeder reactors	Abundant	Low risk	Almost none
Fusion (not viable yet)	Abundant	Low risk	Almost none
^ For more details, follow these links in the leftmost column.

Actions / discussions / next steps:

• Why isn't thorium power a thing yet?
• Would small (shipping-container-sized) thorium reactors be viable?

Vehicles - possible options

Battery-based electric vehicles (EVs)

• Most EVs today use lithium-ion batteries (NMC type). Scaling these up is unsustainable due to the amount of cobalt in them.
  • Best alternatives so far hold less of a charge (i.e. the vehicle gets less range"Range" refers to the distance the vehicle can travel after 1 full charge.). 💬 discussion TODO: Add to this page a simple comparison between NMC, LFP and sodium-ion, in terms of typical expected EV range.
    • LFP batteries are cobalt-free but still lithium-based. Lithium scarcity would be somewhat a problem but not as bad as cobalt scarcity.
    • Sodium-ion batteries are made from abundant materials - they don't have any mineral-scarcity problem (probably). But they hold even less of a charge than LFP.
      • Sodium-ion batteries are quite new to the market (in 2024), and the hope is that they'll become a lot cheaper than existing batteries. That way, EVs could be cheap and durable, with the only tradeoff being the lack of range.^{[QUANTIFICATION needed]} Probably still good enough for city/suburban living.
    • For buses, LFP and sodium-ion are both perfectly fine. The lower energy-densityi.e. the fact that more battery mass is needed to hold the same amount of energy is not a problem, because buses need extra weight at the bottom anyway for stability.

Actions/discussions:

• Next steps for sodium-ion batteries 💬 discussion Is it true that sodium-ion EVs are available in China already, and just not in North America? If sodium-ion batteries are on the market now, how does their cost compare to lithium-based batteries so far?
• How well are EV batteries recycled?

Hydrogen-fueled vehicles

• Hydrogen fuel-cell vehicles would be unsustainable to scale up, because of the amount of platinum & palladium in the fuel cells. 💬 discussion This page needs to mention: Hydrogen production also requires these same metals but it can be done with much less of them and thus could probably be done sustainably.
• Hydrogen combustion vehicles don't have this problem, but their fuel economy (efficiency) is lower.^{[QUANTIFICATION needed]} 💬 discussion 

How bad would this be an issue if renewables or nuclear were to be the main energy sources? 💬 discussion Discussion needed: How much hydrogen would have to be stored at any given time, in such a scenario (let's say if it's all produced through nuclear power)? Probably a lot less than the "renewables + energy storage" approach. I need to write a page explaining why.

Ammonia-fueled vehicles

This wiki currently needs more research:

• How does ammonia compare to hydrogen in terms of:
  • Production energy-efficiency
  • Fuel cell energy-efficiency
  • Catalyst metals required^{[QUANTIFICATION needed]} in ammonia production, and in ammonia fuel cells
  • Storage (mass of materials required per unit of energy stored)

More / See also

This section has not been filled in yet. 💬 discussion TODO: People also have other concerns about renewables and energy storage. I need to direct readers to pages that address those concerns. 💬 discussion Maybe title this page "Decarbonize the energy supply"?