As soon as Sheyan thought of that, he immediately called Dr. Dolittle to inform him of what he found. Dolittle agreed with Sheyan's judgment and also provided him with a very important clue -- if the T-1000 wished to replenish its energy reserves and repair its injuries in this era, it must do so in an environment with plenty of electricity.
In addition, ordinary electric power was far from being able to meet the T-1000's needs. It must perform an ultra-high-compression with a method that the humans in this era had not mastered yet before the electric power could be converted into an energy form that it could use.
Based on Dr. Dolittle's hypothesis, the ultra-high power compression instrument that the T-1000 could make with the current world's technological level would produce a huge waste in power due to the lack of the proper materials. Therefore, its signs could be easily identified by monitoring the flow in the power grid.