Abstract: The present invention teaches an environmentally friendly and convenient way of electricity generation. The electricity generation device contains a rotational arm, a weight, and a moving mechanism. The rotational arm is rotatably joined to an electricity generation mechanism and configured with a track element along its length. The weight is movably configured in the track element. The moving mechanism applies a first moving force to move the weight from a first end side of the rotational arm along the track element's length to a second end side opposite to the first end side. A torque is thereby produced to turn the rotational arm and electricity is generated from the electricity generation mechanism.