Well, that was fast. Just months after U.S. CTO Aneesh Chopra challenged the nation’s utilities to build a “Green Button” system to share their customers’ energy data, California’s biggest utilities have risen to the challenge.

That’s the news from Wednesday’s Green Button event in Santa Clara, Calif., where utilities and smart grid vendors are touting the launch of what could become a nationwide standard for delivering household energy data in a common format.

After months of behind-the-scenes work, Pacific Gas & Electric and San Diego Gas & Electric have announced they’re delivering Green Button data to about 6 million California customers. Southern California Edison plans to roll out the button to its 4 million customers later this year, and according to a White House announcement, utilities in other states, including Texas-based Oncor and Mid-Atlantic utility Pepco, are expected to join the party soon. 

In the meantime, smart grid vendors are launching platforms and applications to make use of this home-by-home energy data. In particular, Boulder, Colo.-based Tendril announced Wednesday that it is now supporting Green Button natively on its smart energy management platform in use by utilities including SDG&E.

Tendril also launched an online “application gallery” where customers can log in, send over their data and start crunching it in new and interesting ways, according to Cameron Brooks, Tendril’s vice president of policy.

“You’re going to see a very simple interface from us, that will allow consumers to drill down and see what their energy consumption looked like over any time period,” he said.

While it’s a bit early to say what kinds of apps will be available, Brooks highlighted a few, including Simple Energy’s online energy-saving game platform, or Dr. Wattson’s rate structure planning tool, that work on Tendril’s platform. Others may emerge from the startup’s latest contest for new app developers.  

Likewise, Opower, which runs the platform that delivers Green Button data to PG&E customers, is pretty much ready to deliver the same kind of data -- energy usage over time, pricing and bill data, and comparisons to past usage patterns -- to any of its more than 60 utility customers, Ogi Kazavozic, vice president of marketing, said.

Opower delivers its targeted, data-driven energy efficiency tips to utilities that collectively have about 60 million U.S. households as customers. About 10 million of them are interacting online with the Arlington, Va.-based startup’s cloud-based platform, Kazavozic said. That gives a sense of the potential market for customers ready to interact with their energy data.

Opower is working with Facebook to develop an app to let customers share and compare their energy use on the social media platform, though the launch date for that hasn’t yet been set. That’s another potential venue for Green Button data to be exchanged.

To get there will take both more utilities participating and more fine-tuning of the system itself, however. Kazavozic noted that today’s Green Button data is coming to customers in typical database formats like CSV (comma-separated values) files, which can be imported into tools including Excel. Upcoming iterations of the data will come in XML (extensible markup language) format, which should make it easier for third-party application providers to interact with it, he said.

The Green Button system is based on a developing standard called Open Automated Data Exchange (OpenADE). The particular standard for that common format, known as Energy Services Provider Interface (ESPI), was finalized in a 1.0 version in October, and the federal government wants to make it a national smart grid standard.

Just how fast it might spread to other utilities in other states is hard to predict. California’s big three utilities are under more pressure than most, since the California Public Utilities Commission is demanding that all three start sharing energy data with their customers as soon as possible.

Another interesting potential market is Texas, where the state’s biggest utilities are consolidating smart meter data on a single portal and recently enlisted Simple Energy to set up its social networking app for them.