It's interesting that I just watched a video[0][1] on Nickel-Hydrogen batteries for grid storage; there are nickel deposits in Japan, so if they really are viable, Japan would not be dependent on anyone for grid storage.
Incidentally, I can't see how being dependent on the US is such an issue for Japan. They are completely and utterly dependent on the US for their national security, without any remaining meaningful popular movement to divorce themselves thereof. The Japanese Socialist party had some language about getting rid of the Anpo treaty, but hilariously, they backed out immediately when they came into power; the Japaense journalist / commentator Akira Ikegami wrote a (Japanese language) book [2] about this era that I thought was pretty enlightening.
[0] Fair notice: the person who runs the channel is an MA and former UI/UX engineer, so YMMV with how far you trust the content.
> I can't see how being dependent on the US is such an issue for Japan
It's an issue the same way the US being dependent on Taiwanese Foundries even though they're an ally of our's.
Should some sort of a global commodities crunch occur (eg. hypothetically, China banning all exports of Rare Earth Metals), then prices are going to skyrocket in the global market because it will take 5-7 years for production to scale up in Australia, Bolivia, and the US.
For critical technologies, it's important to have some level of self reliance. This is why the US is now a net energy exporter, after getting burnt by the spike in commodity prices in 2005-2009 leading to a massive bipartisan push for fracking, natural gas, solar, Athabaskan oil sands projects w/ Harper's backing, etc.
Other large countries with limited rare metal supplies like Germany and India have modeled a hydrogen policy similar to Japan for this reason.
Also, Japan's economic recovery after 2008 was heavily at risk due to the spike in Oil prices, as well as a similar near recession that arose in the aftermath of the OPEC Embargo. Memories of both still resonate in Japanese policy circles.
> Nickel-Hydrogen batteries for grid storage; there are nickel deposits in Japan, so if they really are viable, Japan would not be dependent on anyone for grid storage
I'm not a MatSE or Physicist so I can't speak to the viability of that. That said, I can assume that rolling out any sort of mining and refining infrastructure would take time to scale out.
For example, it took China 15-20 years and an extreme amount of Govt protectionism to become a leader in the rare metals space. It's not that China has more deposits than other countries - it's just that it wasn't cost effective for most other countries to match the prices China was providing.
Incidentally, I can't see how being dependent on the US is such an issue for Japan. They are completely and utterly dependent on the US for their national security, without any remaining meaningful popular movement to divorce themselves thereof. The Japanese Socialist party had some language about getting rid of the Anpo treaty, but hilariously, they backed out immediately when they came into power; the Japaense journalist / commentator Akira Ikegami wrote a (Japanese language) book [2] about this era that I thought was pretty enlightening.
[0] Fair notice: the person who runs the channel is an MA and former UI/UX engineer, so YMMV with how far you trust the content.
[1] https://www.youtube.com/watch?v=2zG-ZrC4BO0
[2] https://www.amazon.co.jp/-/en/%E6%B1%A0%E4%B8%8A-%E5%BD%B0-e...