DAVID GREENE, HOST: It is Earth Day this morning, and we are tracking the billion-dollar sale of the solar energy firm Power-One Incorporated to the Swiss industrial group ABB. This comes after several companies, including Germany's Siemens shut down their solar units. ABB says that falling prices for solar panels and rising energy costs all mean solar is now a competitive source of energy, and Power-One is the second largest maker of solar inverters, which allows solar power to be fed into energy grids.
STEVE INSKEEP, HOST: Also on this Earth Day, the world's greenest office building officially opens its doors next week. It's called the Bullitt Center, and it's an ambitious project by the envi
