The unit of measure of energy used in the SI systems is:

The unit of measure of energy in the International System of Units (SI) is the Joule. This unit quantifies energy, work, and heat, making it a fundamental concept in both physics and engineering. One Joule is defined as the energy transferred when a force of one newton is applied over a distance of one meter. This definition ties energy directly to mechanical work, which is essential for understanding various processes in power engineering, such as the energy produced or consumed by machines and systems.

In contrast, while work is related to energy, it is not a unit of energy itself; rather, it is the process of energy transfer. Torque is a measure of rotational force and is not directly related to energy. Kilowatt, on the other hand, is a measure of power, which is the rate at which energy is used or transferred, but it does not represent energy itself. Thus, Joule serves as the correct answer for energy measurement within the SI system.