Power companies and other utilities may consider keeping their own fault-tolerant networks when the NBN is complete, but there is no reason why last-mile smart grid applications can’t be run over the new fibre infrastructure, according to a technology manager at EnergyAustralia.
People in the utility networking industry have expressed concern over the level of resiliency the NBN would provide in the event of an outage with the Energy Networks Association (ENA) certain most utilities will keep investing in core networks.
The manager of technology governance at EnergyAustralia’s operational, technology and innovation division, Jeff Fry, said for purposes including monitoring and control, utilities deploy physically redundant paths to substations where practical, but in “lower order” uses there is no reason to not use NBN fibre.
There is no doubt that in the rest of Australia, there is the opportunity for utilities to consider the NBN for their smart meter roll-out
Smart grids involve collecting data from energy use points to better monitor and manage power consumption. Data can be sent over the power grid or a networking connection.
For general communications, Fry said NBN fibre would be “much more suited”, but typically utilities run SDH teleprotection services over fibre.
And because teleprotection systems protect the electrical network from destroying infrastructure they must be able to operate within milliseconds.
“In a number of countries legislation now bans the use of telco-managed fibre for the purpose of teleprotection,” Fry said. “In France, for instance, the whole country almost had a complete power outage because the telco was patching fibre and had inadvertently disconnected some critical teleprotection schemes.”
Chairman of the Intelligent Networking Working Group at non-profit alliance Smart Grid Australia, John Nachef, said in principle, it should be possible for the NBN to support the full gamut of communications requirements – not only telephony and broadband services, “but also communications requirements for utilities, health, education, surveillance and so on”.
“With the state government mandating the roll-out of smart meters in Victoria well ahead of the NBN roll-out, Victorian distributors have had no choice but to invest in private communications networks,” Nachef said. “However, there is no doubt that in the rest of Australia, there is the opportunity for utilities to consider the NBN for their smart meter roll-out.”
Smart Grid Australia has prepared a report identifying what aspects of the NBN would need attention for the NBN roll-out to be suitable for supporting Smart Meter communications.
Last year the report was tabled with NBN Co, ENA and various government bodies as a source of information about the subject.
While it’s possible for utilities to use the NBN for smart grid applications, Nachef said there are still numerous practical issues that must be considered.
“For example, if the smart meter uses the NBN for network communications and the ONT [optical network terminal] is powered from a consumer power outlet, then the consumer can inadvertently disrupt communications to the smart meter,” he said.
“As such, grid side powering for the ONT is preferred. There are issues associated with installation and commissioning of smart meters with NBN ONT installations [and] there are issues regarding the location of the ONT (internal versus external). And, of course, there are SLA requirements associated with the communicas services for utilities. The list goes on.”
SGA is working with NBN Co to address these issues with support of Federal communications minister, Stephen Conroy.
“Every variation to practices can have cost implications,” Nachef said. “So while the NBN can accommodate a wide range of applications, as always, the devil’s in the detail.”
Reliability still key for smart grid success
Like core networks in utilities, smart grids will need to be highly-reliable if decisions on power consumption are going to be made from their use.
EnergyAustralia’s Fry said local utilities like to own at least one of the redundant paths for any protection scheme as a transmission feeder can be operated when one communications path is not available.
“Even to the point that it may have to be closed down completely if one path is out for eight hours,” he said.
“Also transmission outages may not be able to be granted for three or six months. I cannot see the NBN waiting that long before they change some fibre over.”
Fry said a lot will depend on cost as to whether electrical utilities will continue to have to deploy their own fibre.
“When a new feeder is built it is often directly between critical substations and it is economic to deploy fibre with the feeder. Given a choice, the NBN fibre will never be as optimised as fibre engineered with protection requirements in mind,” he said.
“For communication to devices and a second path to substation you can consider NBN, but SDH networks sit at the core of some more critical electrical needs and you simply cannot trust NBN fibre as much because it is under a different management regime.”
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