Suppose an array of 30% efficient solar cells has an effective area of 100 m by 100 m. The cells are tilted so as to receive maximum solar flux, an average of 680 W / m ^{2} for a day with 12 hours of daylight. How much energy does this array produce each day? Compare that energy with the output of a 100-MW conventional power plant.
Strategy Energy = power × time. With 1 W = 1 J/s, it is necessary to convert the time to units of s. The solar cell runs for 12 hours, but the power plant runs for 24 hours.