Energy is the next burning issue in the upcoming years when every country requires a huge amount to sustain their economic progress. As the world is rapidly motorized by engines it requires a huge amount of oil to pump it and the oil price is continuously increasing for last few years.
In photosynthesis the reaction is 6CO2 + 6HOH + 672 kcal (radiant energy) or 781 watts - hour gives C6H12O6 + 6O2. For the conversion of 6CO2 in carbohydrate this much energy is utilized.