New York Times: When city leaders and state legislators agreed last year to fund roughly half the $1 billion cost of a new stadium for the Minnesota Vikings, they attached the usual strings for such projects: It had to be architecturally iconic, employ steel made from Minnesota iron ore and offer at least a few cheap seats. It also had to be energy efficient, from lighting to building materials to the sources of its power. In this state, that is not unusual. Minnesota has mandated sharp reductions in energy use...