Pacific Northwest Smart grid demonstration - review of technology
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Pacific Northwest Smart grid demonstration - review of technology
Midwest utility Avista installed smart transformers to improve distribution system efficiency in its service territory as part of the smart grid demonstration project. Pic credit: Avista

In the US, a report analysing the technology used for the Pacific Northwest Smart Grid Demonstration project has concluded a need for greater interoperability.

The technology review analysed the large-scale smart grid demonstration, a US$179 million project co-funded by the US Department of Energy, which began in late 2009.

The initiative, one of 16 regional smart grid demonstrations funded by the American Recovery and Reinvestment Act, involved multiple states and cooperation from rural electric co-operatives, investor-owned, municipal, and other public utilities.

Transactive system

The objectives of the project included improved reliability, energy conservation, improved efficiency, and demand responsiveness.

The technology deployed was a transactive system that coordinated many of the project's distributed energy resources and demand-responsive components.

The report states that the transactive system allowed for a coordinated regional response across the 11 utilities, considered one of the major successes of the project.

It said: "In principle, a transactive system of this type might eventually help coordinate electricity supply, transmission, distribution, and end uses by distributing mostly automated control responsibilities among the many distributed smart grid domain members and their smart devices."

The system showed potential for an 8% reduction of regional peak load with 30% penetration of demand responding to it.

Smart grid demonstration challenges

However, the document also highlights challenges to integrating smart grid technology.

Many of the participating utilities reported that the communications capabilities of various system components were not interoperable.

The source of the incompatibility was sometimes different versions of rapidly evolving communication standards, but even system components that were said to use the same standard were not easily integrated.

On the subject of advanced metering infrastructure, the report said that "not all of the selected systems were found to be equal".

The review said: "The meters’ limitations became evident as the project requested from its utilities relatively fine-resolution power data for each premises. In the worst cases, a utility’s power line carrier-based AMI system could not collect its customers’ interval data at intervals shorter than one day."

Distribution metering was hindered by many utilities not yet having supervisory control and data acquisition systems.

The report said: "Distribution metering, where it existed, sometimes included an incomplete set of measurements that did not even support measurement of the impacts that were to be demonstrated."

The Pacific Northwest Smart Grid Demonstration Project Technology Performance Report concludes that: "These challenges suggest that there is a continued need for work on interoperability standards and conformance testing to reduce the cost of integrating smart grid equipment.

"Third-party testing may be useful to provide independent verification of vendor claims."