> Why do you think we still use a 150 old technology of combustion engines whereas basically every other aspect of civilization has come so far? Because with c

> Why do you think we still use a 150 old technology of combustion engines whereas basically every other aspect of civilization has come so far? Because with current technologies (this might change in the future) it is far simpler to store combustibles than energy in other forms (electric, kinetic (in form of fly wheel)). Specifically for cars it is much faster to fill the tank with combustibles (petrol, diesel, natural gas, LPG) than to recharge the accumulator. Also specifically for electric cars the accumulator has a limited number of charge cycles. Since the accumulator is a (relatively) very expensive part of an electric car this can easily reduce the value of a used electric car by a lot. The storage of electric energy is IMHO indeed the fundamental problem solar and wind has: While we can get (law(s) of large numbers) good large scale estimates how much energy we can harvest, it is not always there at the time that wee need it. So we have to find a way to store large amounts of it to be able to apply the law(s) of large numbers. This is where the problem lies. Of course we can hope for large breaktroughs that will solve these problems, but I'm talking about current technology.