Traditional forms of energy, i.e. fossil fuels have traditionally been cheaper to produce than alternative forms such as solar and wind.

FORBES: Which Candidate's Energy Plan is Better for America?

So when we pursue energy independence, when we continue to reduce our dependence on foreign oil by increasing domestic production of fossil fuel energy but other forms of energy, we enhance our security and protect America's future in that way.

WHITEHOUSE: Press Briefing

That should apply to everything from traditional fossil fuels to nuclear power to all forms of alternative energy.

FORBES: Magazine Article

Biofuels have come to present a special problem because biogenic carbon is excluded from fossil-based caps as proposed to date even though (like most forms of bioenergy) their production is intrinsically coupled to terrestrial carbon stocks.

FORBES: Rethinking Life-Cycle Fuel Regulations

The techniques needed to extract fossil and climatic evidence from this lake bed, and to search for life forms that have adapted to survive in such hostile conditions, would also work on Mars so it is an ideal location to test robots and even to train would-be astronauts.

ECONOMIST: Planetary pretenders