A heat and power station northwest of Stockholm is using an unusual source of fuel to power its operations: Unwanted clothing from the retail chain H&M. The power station was once fueled by oil and coal, but has now been converted to burn materials such as recycled wood and trash, including H&M clothes. By converting old plants to burn biofuels and garbage, Sweden is hoping to edge out the last of its fossil fuel units by the end of this decade.