There is an energy solution. It is magnetic motors. If you put two positively charged magnets close together, there will be a repulsive force for the two to separate. If you put a bunch of magnets strategically positioned together to form a motor, there will never be a need for energy refill. There will be degradation on the magnets which would call for replacement. The replacements will take years to occur. Maintenance costs will be low and fuel costs will be zero. It is practical, and there is plenty of iron in China and Brazil. The magnets can also be constructed from other metals, magnetic polymers or electro or magneto rheological fluids.