HomePlug — the emerging standard for linking smart grid systems and devices over the same wiring that delivers power in buildings — took a couple of steps toward commercialization this week. On Monday, the HomePlug Powerline Alliance released its new Green PHY specification for a low-power, low-cost version of the HomePlug AV technology already used in some 45 million devices sold around the world. And on Tuesday, big Wi-Fi chip maker Atheros said it signed the contract to receive a $4.5 million Department of Energy smart grid stimulus grant it was awarded in November to develop chipsets based on the Green PHY spec, which will also be compliant with the IEEE 1901 global networking standard.
Such moves are meant to give vendors confidence that they can start churning out HomePlug-compliant gear that will help connect homes and apartments to smart grid-enabled energy sensor and control networks in the millions of units. But, like many other smart grid standards in development — such as ZigBee, which is working closely with HomePlug on compatibility — HomePlug is also being deployed in real-world smart grid projects. According to Jim Zyren, senior marketing manager for Atheros’ powerline business, General Electric and San Francisco startup Grid Net are using HomePlug to connect their WiMax-enabled smart meters to home area networks in a $100 million smart grid project by the utility Energy Australia. Meanwhile, German utility Yellostrom is using HomePlug to connect its nifty Sparzähler meters, powered by Cisco and Microsoft and compatible with Google’s PowerMeter home energy platform, to hundreds of new homes every day.
The president of the HomePlug alliance, Rob Ranck, said to us in an interview Tuesday that utilities Consumers Energy and AEP are also using HomePlug in their smart meter deployments. Zyren said he expected more similar-sized projects to be announced soon by other alliance members, a group that includes big utilities like Pacific Gas & Electric, Southern California Edison and Duke Energy; chipmakers ST Microelectronics and SPiDCOM Technologies; and smart grid vendors such as Cisco, Motorola, Landis+Gyr and France Telecom, the latter a big supplier of HomePlug-enabled devices in Europe. By mid-2011, HomePlug-enabled devices should be broadly available, along with a few “bridging products” that will be interoperable with ZigBee, Wi-Fi and the other wireless standards now being adopted for smart grid use, Zyren said.
That’s important, given that most North American utilities already seem to be opting for wireless systems to connect their smart meters to home area networks. Powerline technologies are more popular in Europe, particularly for apartment buildings and homes with thick stone or concrete walls — wireless can have trouble linking from a basement electric meter through those walls, particularly to tens or hundreds of apartments, a problem for which powerline solutions offer a convenient and reliable fix. That reliability could secure powerline technologies a small but significant share of the smart grid connectivity market to come.
In any case, utilities are likely to look to both powerline and wireless technologies to meet the needs of everything from isolated homes to densely packed apartment blocks, Zyren said. The real question utilities are asking about their smart grid networks is “not so much wired vs. wireless, it’s broadband vs. narrowband,” he said. HomePlug Green PHY runs at about 10 megabits per second, sacrificing HomePlug AV’s 200Mbps speeds in favor of lower power requirements and more reliable connectivity over household current that can sometimes be “dirty” with voltage or frequency fluctuations, he said. But Zyren noted that those speeds are still competitive with other low-power wireless solutions, as well as with other powerline communications technologies from the likes of Echelon. GreenPHY is also fully upwardly compatible with HomePlug AV and the new gigabit-class AV2 that’s being developed for release some time next year.
Ranck added that HomePlug is still in the thick of working with ZigBee on achieving full interoperability and setting up a product certification program due to launch sometime next year. At the same time, HomePlug is being tested with smart appliances and electric vehicle charging systems. Given that the smart grid will doubtless be a hybrid of many different communications technologies, it will be interesting to see how well HomePlug and all the other emerging standards end up working together. Stay tuned for more developments.
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