In mid-October, San Diego Gas and Electric (SDG&E) regulatory filings indicated that the company has changed plans to deploy a foundational private WiMAX network as part of its ongoing smart grid deployment, opting instead for a mix of various public and private network systems. This move is noteworthy because SDG&E is a leader in adopting a comprehensive, integrated, smart grid communications strategy. Its abandonment of WiMAX raises questions about the future of private 4G network technology for smart grid. Pike Research has been bullish on the future of standards-based private wireless for smart grids, so naturally we’re asking ourselves the same questions.
Utilities have a longstanding preference for private wireless over public cellular (though this is often overstated as vocal proponents of private wireless usually also have pervasive public cellular deployments, especially for advanced metering infrastructure (AMI) backhaul). However, for critical applications (such as distribution and substation automation), private networks are still considered more reliable and resilient in the face of disruptions, and in some areas, the regulatory preference for returns on deployed assets tilts the field toward private networks. Private 4G technologies such as WiMAX offer a standards-based private solution with strong performance and are expected to displace the plethora of proprietary solutions available. SDG&E, CenterPoint Energy, and Oklahoma Gas and Electric (OG&E), as well as many smaller utilities in Canada, were and are heading in this direction.
Smart Grid Communications Node Shipments (Excluding Smart Meters), As % of Total, North America: 2012-2020
(Source: Pike Research)
However, as SDG&E discovered, reserving guaranteed spectrum for such private networks is challenging. SDG&E had earlier been a showcase customer of Arcadian Networks, which built a product offering around dedicated spectrum that covers most of the United States. However, Arcadian failed to attract enough customers to convince its investors that such networks were the best use of their spectrum, and ultimately failed. This is less of an issue in Canada, where WiMAX-suitable spectrum has been reserved for utility use, leading to greater usage.
Against some of these challenges, public cellular companies have more aggressively supported some of the bandwidth and service guarantees required by utilities, enabled by new capabilities delivered by their own 4G networks. Public telecom carriers have been riding a wave of greater acceptance by utilities for AMI applications (both to the meter and for backhaul), but not all of these are considered mission-critical, at least from the perspective of immediate availability during an outage crisis.
Where will this lead? At Pike Research, we still see a strong trend toward adoption of open standards for public and private, wired and wireless network technologies, and the benefits of integrating these in a unified communications architecture rather than in separate application silos is too great to ignore. The ongoing post-mortems of recent major storms, such as Hurricane Sandy, should help guide in the private versu public network resiliency debate, if utilities are willing to share their experiences. We still see a strong future for private 4G wireless technologies but also strong growth of public 4G networks (40% CAGR, 2011-2020, for unit shipments into distribution automation and AMI backhaul applications in North America). We’ve never said that there will be “one network to rule them all,” much to the chagrin of some network equipment vendors. Diversity will remain the key defining attribute of grid communications networks long into the future.
Tags: Green IT, Smart Grid Communications, Smart Grid Infrastructure, Smart Grid Practice, Utility Innovations
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