If you are looking for energy data, see the website of the US Energy Information Administration (EIA). The EIA operates from within the Department of Energy and is designed to be a policy-independent body. The site is loaded with data, reports, and other information. There is even a nice primer on renewable energy. I made the plot shown above from the international renewables data on the renewable & alternative fuels page. (Click on the image for a bigger version.) At the most recent INFORMS annual meeting (2008), the EIA had a presence at the job fair and was represented in the Doing Good with Good OR energy & environment session, written about here. The EIA hires OR analysts along with statisticians and economists. See their careers page for more on that.
Two modeling tools from the US National Renewable Energy Laboratory (NREL) came up in posts here about WinDS and ReEDS. NREL has many others, which are listed under their Energy Analysis section. WinDS and ReEDS are LP-based. Others involve simulation, stochastic modeling, and financial modeling, among other approaches. Subject matter of the tools varies from micropower to village electrification to renewable energy project cashflow. If you have used or developed any of these tools, feel free to chime in here.