This year's DistribuTech conference in San Diego isn't the insider utility trade show it used to be.

A newfound emphasis on building a "smart grid" – a distribution and transmission grid with two-way communication between homes and businesses and the utilities that supply their power and water -- has picked up a lot of steam in the past year (see Smart Meter Installations Grow Nearly Fivefold).

The third quarter of 2008 saw venture capital investments in energy efficiency and smart grid grow to $272 million, overtaking biofuels' $150 million to capture second-place behindsolarpower companies in the green technology VC investment rankings.

And a promise from the federal government to deliver billions of dollars to support smart grid projects over the coming years  – $32 billion for improving the nation's transmission grid, $4.5 billion of that marked for 50-50 matching grants for qualifying smart grid projects -- is adding fuel to the fire (see Draft Stimulus Plan Has Billions for Smart Grid).

That's put smart grid companies – ranging from smart meter makers like ItronSensus and Landis+Gyr and demand-response providers like EnerNoc and Comverge to communications and networking providers like GridpointGrid Net and SmartSynch – in the spotlight.  

Here are some of the news items that are already emerging from the three-day conference:

Silver Spring Networks, the Redwood City, Calif.-based startup that landed a $75 million investment led by Kleiner Perkins Caufield & Byers last year (see Silver Spring Grabs $75M), announced Tuesday that it's added another utility to a growing list of customers for its smart meter network communications gear and services.

Pepco Holdings Inc., which serves customers in Maryland, Virginia and Washington, D.C., will use Silver Spring's networking technology in a smart meter project aimed at bringing two-way power consumption monitoring and control communications to its 1.9 million customers by 2013, the companies announced.

Silver Spring's technology, which uses an Internet protocol (IP)-based network that communicates through its own meshed radios, has already inked deals with Pacific Gas & Electric Co., Florida Power & Light, American Electric Power and other utilities looking for secure and stable means to transmit data from thousands of meters throughout neighborhoods to collection points that will bring it to utility control rooms.

A rival in that business is Trilliant, which has developed communications networks based on a powered-up version of ZigBee. So far the Redwood City, Calif.-based company has deals with about 100 utilities, including Canadian utility Hydro One.

Those deals have pushed Trilliant over a million communications devices it's installed to date, the company announced Tuesday. In August it landed $40 million from MissionPoint Partners and zouk ventures.

While rival networking companies like these – and the smart meter makers themselves – duke it out over who's going to carry data from smart meters to utilities, the battle over who will bridge the last gap from meter to homes is being joined as well.

The idea behind a "Home Area Network" is to link power-use monitors, thermostats, appliances and other gear together to help homeowners adjust their power use to avoid blackouts and save money. The so-called Home Area Network is now the realm of pilot projects, typically involving a series of partners handling the communications, equipment and software sides of the equation.

San Bruno, Calif.-based Greenbox, which makes software that presents homeowners with information on their power use in a Web-based interface, took part in one such pilot project with Oklahoma Gas and Electric. The company found a small group of homeowners who were interested in adjusting their daily habits to shave dollars from their power bills (see Smart Grid: Test Customers Give Thumbs-Up). 

On Tuesday, Greenbox announced a new set of partners to provide data to its energy management platform --Energate and Radio Thermostat Corporation of America. Energate makes thermostats that use ZigBee to communicate, and Radio Thermostat makes thermostats, in-home displays and "load shed devices" that can curtail power use to in-home devices and appliances that can communicate via protocols including ZigBee, Z-Wave and WiFi (see An Old Favorite – WiFi – Preps to Disrupt Smart Meter Market and Sigma Snaps up Perennial Smart Grid Hopeful Zensys).

Partnerships like these are likely to grow more prevalent as smart meter deployments grow in scope (see For 2009, It's All About Smart Grid and Storage and Acquisitions in Smart Grid: Get Used to It).

Control4, a maker of smart control systems for hotels, is working with GE Home Technologies systems for in-home systems. Home energy monitoring software company 4Home has a deal with smart meter maker Sensus to develop home area network solutions, and has worked with?smart meter company Echelon, SMC Networks and Radio Thermostat.

And Boulder, Colo.-based Tendril Networks has cut deals with nearly 30 utilities to test out its array of home energy monitoring and control devices (see Tendril Expands Its Reach in Smart Homes).