It is well-known that the state-feedback control law based on the speed gradient method can stabilize the pendulum's energy. This control employs measurements of the pendulum's angular displacement and angular velocity. In the present paper, we aim to stabilize the pendulum's energy by using the angular measurement only. We suggest a time-delay implementation of the above state-feedback control law. The resulting delayed static output-feedback practically stabilizes the pendulum's energy. We propose a precise characterization of the energy deviation bound that depends on the delay value. A numerical example demonstrates the efficiency of the results.