The oil depletion allowance is the mack daddy of energy subsidies. Read that IRS publication carefully and you'll note that it also covers minerals and timber. The depletion allowance is not merely a freebie handed to deep-pocketed industries that fund political campaigns. It is easy to see how this tax break encourages accelerated reductions in our nation's vital economic resources that would otherwise be uneconomical without a tax break. It makes no sense to help oil producers pump more crude than their sales forecasts and long-term contracts will justify.
Nuclear power gets plenty of free help. That should end along with the design preference for lightwater reactors. Thorium-salt reactors are the future and allow for safer, smaller designs.
I suppose we'd have to phase out feed-in tariffs just to be fair. Such a mechanism distorts a free market in electricity by mandating different cost structures for renewable sources than for non-renewables. The government's proper role, as guarantor of "the commons," is to invest in infrastructure like long-distance transmission lines that bring renewable sources within everyone's reach. Good transmission lines that bring Montana's wind and the Southwest's sunlight to every grid operator are a much more appropriate public policy objective than cost-diluting tariffs.
Full disclosure: No investments in any energy companies at this time, with the exception of a sweat equity investment in a wind energy startup that never paid me for my services, has had no contact with me for about three years, and looks like it has had no real activity after I left. Oh well.