This week’s Associated Press Centerpiece report focuses on ethanol plants powered by manure and other waste material.

Ranchers have long been fond of saying cattle manure smells like money.

Now, folks in the business of making ethanol are smelling dollars too – in the methane gas emitted by manure at large cattle feedlots and dairies.

The article looks at several companies that are addressing the “criticism that making ethanol uses too much natural gas or coal to produce” by using more environmentally-friendly sources of energy.

Among those highlighted are Kansas-based E3 BioFuels, Texas-based Panda Ethanol and Bion Environmental Technologies.