Light-independent reactions (dark reactions). Light reactions need light to produce organic energy molecules. Dark reactions make use of these organic energy molecules.
Answer: There are 3 major problems with hydrogen as a vehicle fuel, compared to gasoline. 1 - It takes a lot of energy to produce. You have to run a lot of electricity through water to break it down to hydrogen and oxygen. ... It's most useful form is liquid hydrogen, giving far more energy content than as a highly compressed gas.
