comparison of energy for heater and for lights

the following two graphs show the energy consumption between heating and lights. During the night, due to the decrease of temperature outside, it took more energy to heat the room. Therefore, the energy consumption for heating increases during the night and decreases as the temperature rises in the morning.

While the energy for lights is opposite. Except for street lights, most of lights on campus were turned off, using less energy during the night from 11PM to 7AM. However, in the morning around 7AM, because the insufficient sunlight, students consumed more energy for lights.