A kilowatt-hour (kWh) is a unit of electrical energy equal to using 1,000 watts for one hour. Utilities use it to measure consumption and bill customers, and it is also useful for comparing the energy cost of devices, servers, and industrial systems.
In cyber security, kWh matters because many attacks leave power footprints. Cryptomining malware, botnets, or overloaded equipment can raise electricity use unexpectedly, while defenders may monitor kWh trends to spot abnormal activity in data centers, IoT fleets, or operational technology. Tracking consumption can help confirm an incident, estimate its cost, and detect systems that are doing far more work than they should.