乱立している各種標準について簡単にまとめている記事。
–>
The vision of a smart grid includes smart appliances that automatically turn on or off in response to fluctuating energy prices as electric demand peaks and troughs. Intelligent fridges, dryers and other energy hogs could help utilities reduce their needs for new power plants, help consumers save money and ease stress on the environment.
To enable this so-called demand response application, appliance makers need an easy, low cost way to plug into the grid. Today they face as many as a dozen wired and wireless choices, most of them far too expensive and high bandwidth, focused on carrying digital music and video around the home.
In an effort to fill the gap, a senior government technologist laid down the gauntlet before a recent gathering of powerline networking engineers: create a standard to plug appliances into tomorrow’s smart grid soon–or Uncle Sam may do it for you.
Industry representatives at the meeting said the government is over-stepping its boundaries. Forcing the handful of powerline technologies in the market to converge makes no sense, they added.
Government planners knew a lack of standards was one of the big issues preventing the move to a digital, networked power grid. Before its first economic stimulus grant went out, it spent $10 million to launch a new smart grid standards effort organized by the National Institute of Standards and Technology.
NIST is now reviewing industry feedback on a first draft framework for smart grid standards. As a next step, NIST convened in Denver in mid-November a so-called Smart Grid Interoperability Panel of diverse stakeholders to drive the standards work forward.
SGIP includes fifteen Priority Action Plan committees focused on some of the thorniest standards issues ahead. At the first meeting of the PAP-15 group focused on powerline home networks, the national coordinator of smart grid standards at NIST, George Arnold, gave the group his ultimatum.
“It was a pretty competitive group to put in one room,” quipped Arnold. “I almost thought I would have to hire a security guard.”
In the meeting Arnold said NIST could use its experience selecting the AES security standard as a model for creating a technology bake-off for a low cost powerline standard for smart appliances.
“The moment where he most needed a security guard was when he said if you guys can’t get together [on a standard], NIST will decide,” said Stefano Galli, a lead scientist at Panasonic R&D Co. of America who attended the meeting. “There was an uproar.
“Big companies feel this weight of a government decision is not beneficial,” said Galli who also co-chairs an IEEE task force exploring communications standards for the smart grid. “A premature convergence of the home network could create more problems than it solves,” he added.
“I would rather let the market decide, and I think the 70 companies in the HomePlug Alliance would rather have the market decide, too,” said Rob Ranck, president of HomePlug which has released multiple generations of home powerline networking standards. “We’ve met with [regulators], the Department of Energy and Congressional staff members and there doesn’t seem to be a clear consensus that [picking a standard] is NIST’s role,” he said.
“If you go back to the legislation that supports NIST, it talks about interoperability, but it’s not clear whether it sets up the federal government to pick a single winner,” Ranck added.
The industry has tried and failed for years to set a single powerline home networking standard. After four years of work, the IEEE 1901 group is about to finalize a standard that essentially blesses multiple powerline physical layers and media access controllers.
The stakes are as high as the difficulties. The government is keen to ensure its $4 billion in recent smart grid grants is money well spent. Many of the projects include pilot projects in demand response systems.
White goods giant Whirlpool Corp. made a high-profile promise last fall that it will ship in 2011 a million dryers ready to plug into the smart grid—if there is a suitable networking standard the company can use.
“The last thing I want to see is a Wall Street Journal article a year from now saying Whirlpool had to renege on its promise because of the lack of a standard,” said Arnold.
From NIST’s perspective, “the ideal would be to have one wired and one wireless standard,” Arnold told EE Times.
Members of competing Wi-Fi and Zigbee trade groups also attended the meetings in Denver. Some expressed they disagreed with the idea of a single wireless standard—even if their approach was picked.
–>
“Everywhere you look there is something missing,” said Galli of Panasonic.
Ranck of HomePlug said his group’s technology has the broadest backing. It is part of the pending IEEE 1901 standard that provides a mechanism for at least two competing powerline approaches to at least not interfere with each other.
“I think coexistence is achievable, and we will push for coexistence at a minimum,” Ranck said.
However Galli said the 1901 spec makes no mention of smart grid applications, and it mandates a minimum 100 Mbit/second connection. “It’s too expensive to put 100 Mbits/s in an appliance, its overkill,” Galli said.
In an October meeting the 1901 group also dropped plans to support another major contender, the ITU G.hn standard for wired home networks. The G.hn standard specifies data over powerline and other wired media. It supports both a low-cost profile for a few Mbits/s and has attracted broad support in the past year.
But the HomePlug camp is not prepared to back G.hn which was adopted than dropped as part of the IEEE 1901 spec. Ranck of HomePlug noted there are no G.hn products available yet and the G.hn spec may not be formally complete until June.
Engineers could define a generic network socket for appliances and build a variety of different modules based on the IEC 62480 standard for network adapters, Galli said. Each module could cost less than $20 and support a particular wired or wireless network, he added.
However, Arnold charged the PAP-15 group to define a standard that would not require consumers to buy different adapters if they move from one region to another.
Another approach would be to follow the example of Europe that uses the low frequency (9-150 KHz) spectrum to handle the kind of low bit-rate traffic smart appliances need. Galli noted that the U.S. makes this band available for data up to 490 KHz, potentially enabling links supporting data rates up to 500 Kbits/s.
The Prime Alliance–which includes smart meter makers Itron and Landis+Gyr as well as chip makers STMicroelectronics and Texas Instruments–is working to define specs in this area. However, there are few PHY and MAC standards for such data links, Galli said.
The LonWorks technology of Echelon (San Jose) that delivers about 15 Kbits/s is another option. It is used widely in Italy to handle simple apps such as reading meters remotely, however Ranck said it lacks wide support from other vendors.
Galli noted the Denver meeting was the group’s first, with many more to come. He was also quick to point out that the demand response application in the home is just one part of the overall smart grid effort.
“I feel there is undue attention on the home, and other important issues have not received the same level of attention,” Galli said.
Indeed, the Denver meeting included first gatherings for most of the other 14 high priority gap areas NIST has identified.
Posted via email from Ippei’s @CloudNewsCenter info database
Ippei Suzuki's Blog 
Leave a comment