Big Spanish utility Iberdrola – much like its fellow giants Enel of Italy and EDF of France – appears to be settling on its own powerline communications standard to link its 18 million customers or so with smart meters.

The companies behind the technology think it could be a contender for a Europe-wide standard. To get there, however, they'll have to go without France and Italy's biggest power providers as partners.

That's because Enel of Italy has already deployed a 30-million smart meter network using technology from San Jose, Calif.-based Echelon Corp., a company that's also deploying millions more meters in several European markets with its competing powerline carrier system (see Echelon Expands Euro Smart Meter Biz).

EDF of France, in the meantime, plans a 300,000-meter pilot next year to test a number of powerline carrier technologies, one of which is set to win the future smart meter deployment the utility is contemplating for its 35 million customers (see Watteco Launches PLC Tech, Eyes EDF Smart Meter Plans).

Still, the Prime Alliance – made up of Iberdrola, top smart meter makers Itron and Landis+Gyr, smart grid communications provider Current Group, semiconductor makers Texas Instruments, ST Microelectronics and ADD and others – sees itself as the first "truly interoperable" powerline carrier-based solution out there.

That's according to Tom Willie, senior vice president of product development & technology at Current Group and the alliance's vice-chairman. The alliance announced successful interoperability tests last week at a smart metering conference in Barcelona.

"Interoperability is defined exactly the way the telecom guys define interoperability," Willie said. "Anybody's meter device, using their own communications module, can work with anybody's collector... they'd talk to each other in a true plug-and-play setting."

That's a big claim, given the fragmented and often-proprietary nature of utility communications that need to be linked into an overall smart grid network. Even relatively simple smart meter deployments present challenges to interoperability.

Some smart meters use IP or other standards for networking, but transmit wireless signals over proprietary radio systems, for example, while others use proprietary networking over standard wireless technologies like WiFi or ZigBee (see Smart Grid: A Matter of Standards).

But governments in Europe – and the United States – are demanding interoperability first, and standards eventually, from utilities' smart grid systems. That's led to a rush of technology partnerships in the space, driven by billions of dollars in government incentives in the U.S. and abroad (see Smart Grid Standards Roadmap Unveiled).

In Europe, utilities face mandates to give all their customers smart meters in the coming years. Those two-way communicating meters will allow for remote reading, shut-off and start-up, power quality measurement and eventual linkage with in-home energy control networks.

In North America, most utilities have chosen wireless communications to link their meters in local-area or neighborhood-area networks, though Duke Energy is looking at powerline carrier for millions of meters (see RF Mesh, ZigBee Top North American Utilities' Wish Lists and Ambient Extends Smart Grid Contract With Duke).

But in Europe, powerline carrier (PLC) technologies have taken the lead. PLC uses the same electricity that powers homes to carry information, and typically links smart meters to concentrator boxes located alongside transformers, which tend to interfere with the signal being carried further up the electricity grid.

Wireless technologies work well for suburban-type neighborhoods, but the dense apartment blocks of Europe present a challenge. Any wireless signal that could reach from basement meters through yards of concrete to top-floor apartments would likely be too expensive to contemplate for millions of meters.

Powerline carrier technologies, on the other hand, travel on the wires that carry power, making them ideal for big apartments or other dense residential and commercial environments.

Current Group has deployed a similar, but distinct, technology at Xcel Energy's $100 million SmartGridCity project in Boulder, Colo., Willie said.

There, Current links about 15,000 of an eventual 42,500 homes with smart meters using a modified broadband over powerline technology, he said. BPL is like PLC but with greater bandwidth, though typically at a higher price of deployment, and can be used over higher-voltage transmission lines as well (see Distribution Automation: Smart Grid's Quiet Efficiency Offering).

At the lower voltages that exist in distribution grids, newer powerline carrier technologies use orthogonal frequency-division multiplexing, the same technology behind cable and DSL communications, to broaden the bandwidth available, Willie said.

North American utilities tend to find PLC more expensive, since fewer homes are served per transformer, multiplying the number of concentrator boxes required, he said.

But to utilities that have said PLC is more expensive than wireless systems, he pointed to Iberdrola's price target of €35 ($52) per smart meter - less than half the $100 to $150 price often cited in North American deployments - as a gauge of its potential to save money.

The Prime Alliance is talking to other utilities with an additional 12 million or so customers, Willie said, though he wouldn't name them.

As far as becoming Europe's favorite smart meter standard, the alliance could face significant competition from Italy and France, Willie said.

Any technology that EDF picks for its system-wide smart meter deployment may "drive a de-facto standard" on the continent, he said. But EDF hasn't reached out to as wide a coalition of vendors – Prime has eight members now, but hopes to have 15 more soon and more than 50 by mid-2010, he said.

And Enel, which sells its Echelon-based PLC technology to other utilities, might face trouble in adapting its own system for other customers' disparate needs, he suggested.

"Prime is not saying that utilities won't make proprietary decisions," Willie said. "What we're saying is, there exists an alliance that has created a technology that's multi-vendor interoperable."

The alliance isn't limiting its sights to Europe, he added - the alliance is working on a wireless technology that could link seamlessly with its PLC network, he said.

But on either side of the Atlantic, the alliance will need to land more utility customers to stand a chance at becoming the standard it wants to be, said Ben Schuman, analyst with Pacific Crest Securities.

I know the idea is to create an open PLC architecture for everyone to use," he said. "But until I see another utility join the alliance I will consider it Iberdrola's home grown standard, just like EDF and Enel."

Interact with smart grid industry visionaries from North American utilities, innovative hardware and software vendors and leading industry consortiums at The Networked Grid on November 4 in San Francisco.