SANTA CLARA, Calif. – Some smart meter projects are essentially on hold while engineers work to break up a long jam delaying the definition of a key standard for tomorrow's home energy networks. Meanwhile, a U.S. effort to define a broad suite of smart grid standards is gearing up to publish an update of its guidelines.
A working group of the Zigbee Alliance developing the Smart Energy Profile 2.0 (SEP 2) standard for home area networks voted in April to add a second software stack to the standard, said one source close to the effort. The move adds a UDP-based stack that would support meters that need to run for up to 15 years on a local battery, something that could not be supported with the TCP-based software previously defined in the draft standard.
"We need both stacks, there's no doubt about that," said the source.
The group has yet to define a plan for how and when it will complete work on the additional software and the standard. Members of the Zigbee Alliance are circulating a timeline of recommended milestones that is expected to be reviewed by the full working group in a face-to-face meeting in a few weeks.
"The uncertainty around the standard will delay deployments, so we have to work at minimizing the uncertainty risks," said the source.
A spokesperson for the Zigbee Alliance said the group does not discuss standard development activities publicly. The spokesperson said the group did not vote to add a second software stack to the Smart Energy standard.
The SEP 2 standard is a significant re-write of the existing Smart Energy Profile 1.0 spec that only supports Zigbee. SEP 2 lets a variety of networks including Zigbee, HomePlug powerline or Wi-Fi carry data about energy use between smart meters and devices in the home.
Due to significant changes in the upgraded spec, SEP 1 devices will not be able to communicate with SEP 2 devices and vice versa. However SEP 1 hardware will be able to run the new code.
Bob Heile, chairman of the Zigbee Alliance said the SEP 2 standard could still be finished by the end of the year. Another source said the work on the additional software will drive completion of the standard to 2012.
As many as 20 million SEP 1 smart meters have already been installed by utilities, Heile said. The SEP 2 effort has been at times contentious, but that's not unusual with standards groups, and many utilities continue to move forward, he said.
"There are a lot of companies involved in this effort and some have very strong feelings about the way forward and they all have their own set of interests," said Heile.