Radio's Part in the 'Smart Grid'

You've probably heard a little (or maybe more) about the "Smart Grid" — a general term for various methods of making our energy distribution systems more adaptive and flexible, thereby conserving energy through reduced waste and more efficient consumption patterns.

What you might not have heard is the critical role FM radio broadcasting may soon play in this space.

Let's start with an overview.

Our current power distribution system is essentially a one-way environment — it is designed to deliver power from source to load, and does so in a fairly effective and reliable manner.

But this distribution could be much more efficient and even more reliable if it had an integrated, two-way "backchannel" for monitoring and controlling the distribution in a more adaptive and granular manner.

The Smart Grid adds just such a mechanism through the addition of multiple return and control paths layered atop the existing power-distribution network.

This is not an entirely new idea; electric utilities have had it in mind almost since their beginnings, but its broad application has been elusive.

Today's technology and generally heightened awareness of the need for such energy efficiencies may finally bring the concept to fruition, however, and the Smart Grid is the culmination of that process worldwide.

One of the central components of the Smart Grid is the ability for utilities to control their customers' usage of electricity during periods of peak demand. Given adequate control, utilities could avoid forced service outages during such crises. Meanwhile, loads could also be managed more efficiently and overall consumption substantially reduced, along with other benefits.

Radio Thermostat makes 'communicating thermostats' that support various types of communication required by system integrators — RDS as well as ZigBee, Z-Wave, WiFi and 6LoWPAN. While this may have a real "big brother" ring to it, most proposals would allow consumers to voluntarily opt-in or out of these programs. There are also proposals to allow tiered electricity pricing during different dayparts, so consumers could defer certain power-consuming activities (e.g., laundry or dishwashing) to times when power costs are cheaper. And some elements simply involve messaging that informs consumers of current conditions and encourages appropriate behavior, with no direct device control.

Getting there

A number of methods have been proposed for distribution of such control signals from utilities to their customers.

Various studies have concluded that distribution via FM-RDS is perhaps most advantageous for this application, given its wide existing deployment, good building penetration, service robustness, low delivery and consumer-equipment cost, and its likelihood of remaining around and unchanged for a considerable period of time.

Another benefit of RDS distribution arises from the fact that FM stations' coverage in a market typically are well matched to the service area of that market's electric utilities. This offers a form of coarse addressability inherent to the terrestrial propagation footprint of FM stations (more on addressability below).

Given that the FM-RDS delivery path is already well established, what's needed to get this concept working are elements on both ends of the path.

At the head end, an entity would be set up to collect messages and commands from one or more utilities, verify and code them securely, and deliver them to the appropriate radio stations' RBDS encoders — where they would most likely be inserted as RDS Open Data Application (ODA) content.

At the receive end, consumer homes will need to be equipped with power-consuming/controlling devices that include FM-RDS receivers and associated user interfaces. Development on both of these processes is already well underway.

The upstream part

A number of entities and initiatives have coalesced in recent times in this space (particularly in California, where Smart Grid regulatory processes are farthest along), including one formed by some former broadcasters and RDS experts called e-Radio USA, or ERU.

The company is signing deals with various utilities, and plans to contract with FM broadcasters in these utilities' service areas to obtain access to adequate RDS bandwidth. (One or more stations might be used in each market.) ERU would provide, install and maintain the necessary equipment at radio stations, coordinating with station technical staff.

ERU has developed a format for its RDS-delivered control data that it calls Utility Message Channel (UMC). It includes data fields for identifying multiple utilities, device types and locations. Such data could be used to target consumers' homes in specific zones within the station's coverage area, or only target certain devices. Ultimately, ERU plans addressability down to the individual device.

As is expected of most such entities, ERU's scope is end-to-end, thus it also designs the RDS receiver modules that would be installed by device or appliance manufacturers to enable response to utilities' UMC control signals.

The downstream part

The devices envisioned at the consumer end include the Programmable Communicating Thermostat (PCT), device switches, smart appliances, message-display terminals, and even smart chargers for hybrid vehicles.

RDS is not the only method proposed for communicating with these devices, however. A number of involved companies have therefore formed the U-SNAP Alliance, which will provide a standard interface for PCTs and other home automation devices, allowing plug-in of various receiver modules to respond to utility control signals, whether they are delivered by RDS or other methods like WiFi or Ethernet, including some other networking formats already developed for such control (such as ZigBee, Z-Wave or FlexNet).

The PCT reference design that ERU proposes would have a non-removable ("mandatory") RDS receiver plus a U-SNAP port for addition or later upgrade to another delivery method. ERU's receiver also allows firmware upgrades to be delivered over the air.

Beyond PCTs, device switches would be attached to specific, high power-consuming equipment such as air conditioners or hot-water heaters. These would allow a utility to control the use of such units via RDS or other message-delivery paths, so that during emergency periods, loads could be rebalanced by temporarily shutting down only these devices, and not resorting to "rolling blackouts" that turn off all electric power in a given area.

Meanwhile, smart appliances would allow consumers to program their use to respond to tiered pricing or other offers by utilities, again communicated to the appliances via RDS or other pathways. Finally, a simple message display terminal could also be addressed by utilities, to alert and advise consumers regarding energy usage during critical periods.

The use of RDS for utility load management in the Smart Grid seems like a win-win, allowing broadcasters to provide valuable new service, while collecting some new revenue for minimal effort. Stay tuned to companies like ERU and others for further development in this area.

Skip Pizzi is contributing editor of Radio World.