It's official – radio frequency (RF) mesh and ZigBee are the most popular technologies for North American utilities and their smart meter plans.

The confirmation comes in a report from Atlanta-based energy research firm Chartwell, which talked with more than 100 utilities in the United States and Canada.

RF mesh technology, either deployed by smart meter makers like Itron, Landis+Gyr and Elster or added to meters by technology providers like Silver Spring Networks and Trilliant, is the favorite of 42 percent of those utilities, said Mark Hall, research analyst for Chartwell.

Coming in behind RF mesh are tower-based smart meter communications, which is mainly led by smart meter maker Sensus, Hall said. Sensus has about seven million meters under contract and has more than one million endpoints installed for utility Southern Co., he said.

Using cellular networks, which is more popular in Europe, hasn't caught on as much in North America, though efforts by companies like Echelon and SmartSynch seem to be goosing interest among utilities, Hall said (see Echelon, T-Mobile Team on Smart Meter Contracts and Your Electrical Meter Becomes a Cell Phone).

As for linking smart meters and in-home energy monitoring and control devices, ZigBee remains the favorite future technology for North American utilities, he said. Two out of five said they're planning to center their efforts around the low-power wireless technology based on the 802.15.4 protocol, which is used by such home area energy device makers as Tendril Networks, Energate, Onzo and demand response provider Comverge (see The Smart Home, Part I and The Smart Home, Part II).

That makes sense, given that some of the utilities farthest ahead in smart meter deployments, such as Pacific Gas & Electric, have said they'll be looking to ZigBee for that link-up. The ZigBee Alliance includes all the major smart meter makers, as well as many major utilities and energy services companies, and the Department of Energy recently named ZigBee as a potential standard for federal smart grid efforts (see DOE Lifts Smart Grid Stimulus Cap to $200M).

A "distant second" to ZigBee was the idea of using the same RF mesh technologies that smart meters use to extend into homes, Hall added. Other possibilities, such as Z-Wave, WiFi and powerline carrier technologies, were represented in smaller numbers, he said.

The Z-Wave Alliance, for its part, wants people to know that European meter makers like United Kingdom-based Horstmann and Denmark-based Kamstrup are adopting its low-power wireless technology, even if North American utilities seem to be choosing ZigBee at present (see Sigma Snaps Up Perennial Smart Grid Hopeful Zensys).

And a new group called the U-SNAP Alliance is trying to gather momentum behind the idea of making home energy devices with modular communications capabilities that could include ZigBee, Z-Wave, WiFi or new technologies to come (see U-SNAP: Modular Home Energy Communications).

Of course, all of the figures discussed so far have to do with utilities' plans for the future, Hall noted. What they actually have out in the field right now looks significantly different.

For example, RF mesh users Itron and Silver Spring lead the list in terms of contracts for future smart meter deployments, Hall said. But when it comes to deployments, the TWACS (two-way automatic communications system) powerline carrier technology from smart meter maker Aclara may actually be more prevalent than those using RF mesh, he said.

Aclara has millions of endpoints deployed by PPL (PENN), Puerto Rico Electric Power Authority and various electricity co-ops around the country, he said.

Furthermore, two-way communication smart meters, which are generally known by the acronym AMI (advanced metering infrastructure), still only represent about 10 percent of the 86 million or so communications-enabled meters in the U.S. and Canada, Hall added.

The rest fall into what's known as the AMR, or automatic meter reading, category, he said. Those are meters that can send out data to passing utility trucks to avoid manual reads, but don't have a way to receive data. Itron is the market leader in that field.

Hooking up those AMR meters for two-way communication is something Tendril is working on right now with New England utility NStar and others (see Tendril Moves to Link Up Old-School Meters).