> I do think there are many challenging engineering problems along that path, and I’m not convinced it’s tractable at all, much less likely to outpace advances

> I do think there are many challenging engineering problems along that path, and I’m not convinced it’s tractable at all, much less likely to outpace advances in battery systems. I disagree on that last part. Fuel cell is moving at warp speed right now, and batteries are losing ground at a rapid rate. We're seeing fuel cells move into everything from e-bikes to aircraft. If there's any kind of disruptive event here, it will be fuel cells replacing batteries at a much faster rate than expected.