Most news coverage of energy and the environment is in love with the new: cool new technologies, new research, and all the impressive creative energy that’s being poured into these fields. Yet one of the most significant factors shaping the energy field is the power of old decisions.

Take, for example, the power plants that supply our electricity. The U.S. Energy Information Administration released a report on the age of the nation’s generating stations this month, and one of the most striking things is how old they are. Half of our generating capacity (51 percent) is at least 30 years old.

But the other interesting point is the age of different kinds of plants. For example:

If you look at the