Lots of fuels (like petrol) are a lot more energy dense than out best batteries. If we can synthesize fuels like that just using electricity as an energy source (that can be generated from renewables) then you have a carbon free dense store of energy that can be used to power a vehicle for a long distance without refueling.
The problem with these (fuel cells etc) is that the conversation rate is inefficient, wasting a lot of energy. As we are not using 100% renewable energy this means carbon is being released still.
If we had an entirely renewable energy grid (with oversupply when sunny/windy etc) then those energy losses would not matter.
Lots of fuels (like petrol) are a lot more energy dense than out best batteries. If we can synthesize fuels like that just using electricity as an energy source (that can be generated from renewables) then you have a carbon free dense store of energy that can be used to power a vehicle for a long distance without refueling.
The problem with these (fuel cells etc) is that the conversation rate is inefficient, wasting a lot of energy. As we are not using 100% renewable energy this means carbon is being released still.
If we had an entirely renewable energy grid (with oversupply when sunny/windy etc) then those energy losses would not matter.