This week has seen a host of new projects, partnerships and reports come out making clear how big a role natural gas is going to play in green energy‘s future development. How can startups get involved in the process? General Electric’s project with eSolar to install solar thermal systems in a GE gas-fired power plant represents one example, a fairly rare one, of renewable energy serving as a backup to fossil fuels. Usually, the process works in reverse, with reliable gas backing up intermitent wind and solar power — the kind of “firming” resource that GE’s new fast-ramping gas turbine is aimed at making more efficient. Matching gas to renewables is a tricky game, and requires all kinds of smart grid communications, controls and platforms to run smoothly. At the same time, natural gas is increasingly viewed as a viable transportation fuel, if only for fleet vehicles, according to studies out from MIT and the International Energy Agency this week. MIT sees the potential for natural gas-fueled trucks, vans, and other fleet vehicles to reduce U.S. oil consumption by about 1 million barrels per day, or 5 percent of daily demand — at a cost of 2 trillion cubic feet of natural gas, or about 10 percent of U.S. supply. Of course, without numerous and easy-to-use refueling stations, natural gas-fueled cars won’t make it past fleet parking lots into the broader consumer market. Technologies that help fleets maximize efficiency of the natural gas they do choose to use could find their way into those markets eventually — even if they’ll probably never be as popular as the plug-in electric car charging crowd.