As far as I can tell, the difference is in consumption/durability. They don't buy cars because they'd be hooked on the gas supply chain. But if you buy a sola

As far as I can tell, the difference is in consumption/durability. They don't buy cars because they'd be hooked on the gas supply chain. But if you buy a solar panel, it's yours. And the ship has sailed on lithium batteries -- cell phones are permitted in limited contexts.