The smart grid news of the week starts out with a new big win for Silver Spring Networks -- though just how big, we’re not sure yet.

Chicago-area utility Commonwealth Edison, which has been working with Silver Spring since 2009 on a smart grid pilot, announced this week that it would ask the Redwood City, Calif.-based startup to help it with a multi-billion-dollar smart meter rollout.

ComEd recently got its $2.6 billion smart grid plan approved by the Illinois state legislature, after a contentious fight over whether the costs to customers justified the improvements. About half of that money will go to upgrading the grid itself, while the other half will be used to “digitize” the system -- a category that includes smart meters.

Silver Spring declined to comment on the scope of its plans with ComEd, but it will be opening an office in the Chicago area with 30 to 50 employees, according to the Chicago Tribune. Coming in April will be a plan for the company’s smart grid “platform” for the utility, which could include smart meters, as well as the home energy management, demand response, grid sensing, solar system management and plug-in vehicle systems Silver Spring is developing on its own and with partners.

Silver Spring filed for its IPO in the summer of 2011, but it hasn’t pulled the trigger yet -- in fact, it recently went back to private investors to raise $24 million, on top of the $275 million or so it has raised over the years. The smart grid networking leader could use a big new contract to add to the few large-scale smart meter deployments that make up most of its business. It could also use a customer willing to implement the broader range of smart grid services it wants to deploy to increase the value of its smart meter networks.

In other news:

- Want to build a smart grid app? Go talk to Tendril Networks. The Boulder, Colo.-based home energy monitoring startup has launched a new contest for independent developers interested in designing applications for Tendril’s energy management platform, complete with a $5,000 prize to be given out later this month.

This isn’t a first for Tendril. The Boulder, Colo.-based startup opened up its applications developer program in August 2011, and has already seen some of the apps put to use by utility customers. San Diego Gas & Electric, for example, is giving customers access to Simple Energy’s energy-saving game software, built to run on Tendril’s platform, to help participants in its Biggest Energy Saver challenge.

By the way, SDG&E just announced that participants in the White House-sponsored contest doubled their energy savings, with one customer cutting nearly half of her home energy use and winning a laptop as a result. In December, Texas utilities Oncor and Centerpoint announced their own contest results, with grand prize winners getting a Chevy Volt hybrid and runners-up landing home energy management gear from Tendril and General Electric.

- Siemens hasn’t been buying smart grid companies at the same pace as rivals like ABB and Schneider Electric, but its purchase of meter data management startup eMeter last month was seen as the start of what could be a new round of acquisitions for the German engineering giant.

Looks like Siemens is indeed ramping up its energy acquisitions. On Wednesday, it announced it acquired Pace Global Energy Services, a Fairfax, Va.-based company that manages more than $5 billion in global energy spending for clients with about $100 billion in energy assets. Siemens plans to use the acquisition to “extend our reach into the energy market and enhance our current building automation portfolio,” Dave Hopping, vice president of Siemens’ U.S. building automation business unit, said in a press release.

That would appear to put Siemens in competition with Schneider Electric, which bought Summit Energy, an energy procurement company that brokers about $20 billion in annual power purchases for some 650 clients, in March 2011. Schneider spent $268 million to buy Summit, with the goal of integrating its customer energy procurement system into its broader smart grid and building controls platforms.

Siemens didn’t disclose how much it paid for Pace Global, though one might speculate that it might have paid about a quarter of what Schneider paid for Summit, given that Pace Global manages about one-quarter of the energy purchases that Summit does.