That is an intriguing question, and represents an interesting challenge for radio frequency identification. I would need to know a little more about how the theft occurs. Are the power lines being stolen by fairly unsophisticated criminals who climb poles and cut transmission lines, or do more sophisticated thieves come equipped with cherry pickers and cut the lines?
If they are climbing poles, then it might be possible to affix an ultrahigh-frequency (UHF) tag to a pole and a UHF reader with a cellular transmitter nearby. When a human body passed over the tag, it would prevent that tag from being read (the body is mostly composed of water, which absorbs UHF energy). So when a tag disappeared, this would be detected by the interrogator. A software application running on the reader could be set up to trigger an alert that someone was climbing a pole. This information would be transmitted via the cellular connection, and the police could be sent to apprehend the thief.
Another possibly would be to place tags on the wire itself, as well as readers on the poles. When a line was cut, the tag would fall with the wire and no longer be in the read field. That could trigger an alert that a theft was in process.
I am unsure that either of these solutions would be the best call for your application, however. You would need a lot of readers to cover an entire city’s power grid, and placing the devices outdoors would mean they would need to be protected from the elements. You would also need to run power to each interrogator. This could get expensive. Perhaps placing a video camera on one pole and having it cover an entire street might be a better solution. With the price of cloud computing falling, performing video analytics is no longer prohibitively expensive.
I would suggest contacting a knowledgeable RFID systems integrator who could estimate the costs and do some feasibility testing. I can recommend some companies—feel free to contact me directly.
—Mark Roberti, Founder and Editor, RFID Journal
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