Research firm IDC has issued a new report that says that renewable energy is set to receive the lion’s share of new revenues from the stimulus– but that smart grid and energy efficiency companies should expect a decent share of that money.

The study found that the $787 billion stimulus package signed into law by President Barack Obama last month is likely to generate $77.6 billion in sales for the broader green energy industry, according to Bloomberg.

About $66 billion of that will head towards renewable energy. Energy efficiency improvements, like programmable thermostats and building energy management systems, could garner $3 billion in sales from stimulus spending.

Another $8.6 billion will be directed toward so-called “smart grid” equipment and technology to add two-way digital communication and controls to the nation’s electricity transmission and distribution system, IDC found.

The stimulus package specifically addresses $11 billion toward smart grid, including $4.5 billion in matching grants for smart grid projects to be chosen by the Department of Energy in a process that’s still being worked out.

However there are several other pots of stimulus money could also be open to smart grid companies, which could double that $8.6 billion in projected revenue growth, Jesse Berst, head of smart grid consulting firm GlobalSmartEnergy, said in a recent online analysis.

One example is the $7.2 billion set aside for expanding broadband services to underserved areas, he said. Utilities and partner companies that can show bringing smart grid services to rural areas also includes a broadband component could benefit from that, Berst said – an option that giants like IBM are already considering (see Broadband Over Powerline Brings Smart Grid to Rural Areas).

Likewise, smart grid-related projects that can fulfill a request to “improve energy efficiency in the transportation, building and other appropriate sectors” could seek a piece of the $3.2 billion to be distributed by states through energy efficiency and conservation block grants, Berst wrote.