A friend of mine, who used to work for ExxonMobil (NYSE:XOM), once told me that the firm considers itself an oil and gas company, rather than an energy company. The company is unabashed about this, using exactly such language on its website's "About us" page.

While the rest of the integrated energy supermajors also derive nearly all their income from hydrocarbons, many have taken a green brush to their corporate branding. When it comes to renewable forms of energy like wind and solar power, some firms, like BP (NYSE:BP) and its $2.9 billion in investments since 2005, are arguably walking the walk. For Royal Dutch Shell (NYSE:RDS-A) (NYSE:RDS-B), I think it's been mostly talk.

Shell came clean about being green at a recent strategy conference, revealing that it's no longer planning significant investment in renewables like wind or solar going forward. The company will continue acting as a biofuel shelter for promising technologies in that realm, which is a closer fit for the firm's core competency in crude.

I suppose this turn of events can't come as too much of a surprise, following Shell's step away from the London Array. The world's largest offshore wind project has been in limbo since the firm backed out last May.

Given the collapse in commodities prices, it's hard to blame Shell at this juncture for shying away from projects with less viable near-term rates of return. Other companies, from international firms like Chevron (NYSE:CVX) and ConocoPhillips (NYSE:COP) to national champions like Petrobras (NYSE:PBR), may now be questioning their commitment to these higher-risk pursuits.

Until now, I had been viewing these energy giants as something of a funding savior for alt-energy startups, as venture capital has choked up and government budgets have taken a beating. If I were such a budding business, I'd be worried about this move by Shell, and would hope the reversal on renewables doesn't catch on with its peers.

Related Foolishness:

  • Check out all the latest happenings in solar.
  • Obama's attempt to punish Big Oil will backfire.
  • Here are 15 more reasons to like ExxonMobil.

Petrobras is an Income Investor recommendation. Drill into the newsletter's other dividend-paying prospects with a free 30-day trial.

Fool contributor Toby Shute doesn't have a position in any company mentioned. Check out his CAPS profile or follow his articles using Twitter or RSS. Don't make the Motley Fool's disclosure policy angry. You wouldn't like it when it's angry.