Sure. Let's all do this. Let's power up our cars by improvised H2 generators using discarded aluminum cans. Ignore practical considerations such as: does the average household generate enough alumionum waste to cover its energy requirements, prioce and safe handling of sodium hydroxide, disposal of aluminum sodium oxide etc.
Fast forward 1 year. Most people who had started using the aluminum powered cars have abandoned the system.
Why? Not enough waste aluminum generated by the household.
Why? The price of canned soda has skyrocketed.
Why? The deposit on cans has suddenly gone up from 5-10cents per can to %1.50 per can
Why? Canners can't get cheap aluminum anymore
Why? Aluminum doesn't get recycled anymore because it gets burned instead. So canners need to buy "new" aluminum, which costs a lot more. Why? It takes a lot of electricity to refine from ore.