Building a better smart grid with Echelon’s power line communications


By Larry Colton

Utilities gain advantages when they choose to build their smart grid solutions with ISO standards-based power line communications instead of meshed radio frequency (RF).

Power line communications (PLC) lets utilities leverage their network management expertise, offers proven reliability and performance, increases grid intelligence, and provides a foundation for open smart grid solutions.

Utilities already own and manage a vast network: the electricity grid that delivers power to their customers. Through decades of investment and operations, they have become experts at managing their electricity network. As a result, they have extremely reliable networks that reach 100% of their customers. Echelon’s NES System uses the power lines that run between the utility’s low voltage distribution point (or low voltage transformer) and the end user. At each transformer, a take-out point communicates data over a WAN to the utility’s service centre. The WAN may be of any type, as long as it is IP-based. Typically, the NES System is deployed using a cellular carrier, to provide a backhaul for the data. This complementary architecture of neighbourhood power line networks and RF backhaul networks lets the domain experts manage their respective system elements, making the entire system less costly to deploy, operate, and maintain.

Conversely, utilities that employ private meshed RF networks are faced with a new, untested system with potentially quirky management and maintenance operations. Since these solutions are just being deployed — none have been in widescale operation for more than twelve months — they’re basically unproven.

Utilities looking to roll out new smart grid and metering solutions must base their decision on real world data from other utilities. PLC technology embeds communications and intelligence directly into the electricity grid. The latest generation of PLC technology — which Echelon’s NES System is built upon — is based on global control and communications standards, and is a proven technology deployed in tens of millions of homes worldwide. Next generation PLC supports multiple utility offered services, not just meter reading, it integrates easily with IP-based WANs, and it’s highly scalable and reliable.

The NES System embeds its underlying PLC technology into a utility’s core asset: the electricity infrastructure. This gives solutions built on the NES System a level of grid intelligence that a meshed RF solution cannot match. Grid intelligence provided by the NES System includes:

  • Line management intelligence: Utilities can better monitor outages, reduce service restoration time, and verify that service has been restored.
  • Power quality: Though it’s not yet widely regulated, power quality is an important aspect of the smart grid. The NES System measures and detects events related to voltage surges and sags, phase changes, long and short outages, and total harmonic distortion.
  • Power line communication statistics: This data can alert utilities to potential faults on distribution lines.

The NES System and its underlying power line signaling and communications technology are the most proven, reliable, and scalable of any smart grid solution available today:

  • Over 30 million electricity meters using the underlying power line signaling and communications technology are in operation to date.
  • The Swedish utility E.ON has seen a 50% drop in meterrelated customer service calls since deploying its NES-based AMI solution.
  • The Swedish utility Vattenfall AB has been able to read 99.7% of its 600,000 NES meters every day and 100% of its meters within 48 hours.

Utilities must be able to make smart grid decisions today that don’t hamper their flexibility tomorrow. Future services like residential demand response, incentive pricing, prepay service, and alternative energy buy-back plans are very real possibilities. To ensure the maximum level of flexibility to utilities, Echelon’s NES System is based on four open international networking standards.

Created as a service oriented architecture (SOA), the NES System software is designed for ease of use and rapid integration with new and existing enterprise software applications. The web service interface helps ensure competitive software services by multiple suppliers.

The NES smart meters have multiple interfaces for extending services within a residence through a combination of hardware and software, including ModBus, ZigBee, M-Bus or LonWorks® interface (ISO/IEC 14908) for PLC-based LonWorks smart appliances or HANs.