The one thing you can count on an electricity meter to have is, well, electricity. A steady source of (for all practical purposes) unlimited power makes engineering a wide area, low bit rate network easy, and gaining the benefits of real time control a straightforward, relatively low tech proposition.
Other utilities aren’t so lucky. On the whole, it’s not a great idea to pump 120 volts into a gas or water meter, even if it were cost effective. So real time control requires battery power, at least for now. To get smart meter levels of performance out of a battery powered network means developing better technology. On-Ramp Wireless is trying to do that for widely dispersed applications, such as agricultural irrigation, where the basic power problem is compounded by distance.
The company makes 2.4 GHz modules costing $35 to $50 that communicate with access points (in the $15,000 to $20,000 range) up to 20 km away. That allows coverage of an area of approximately 750 square km. The secret sauce is low power technology that conserves battery life while maintain long distance links.
According to a company spokesman, if it’s a simple meter reading job, where data is collected from a single point once a day, it could be 12 years or more between new batteries. More demanding tasks – say, managing and gathering data from 6 or 8 irrigation sensors half a dozen times a day – might require annual battery changes.
Smart meters are the first spread consumer use of Internet of Things technology, made possible by a unique proximity to abundant electricity. But follow on applications have been slow in coming. When power is more or less taken out of the equation – as On-Ramp and others are in the process of doing – expect adoption to accelerate.