July 2 (Reuters) - Dominion Resources Inc closed on the sale of the 515-megawatt (MW) State Line power plant in Hammond, Indiana, to BTU Solutions of Sugar Land, Texas last week, the Virginia power company said in a release. BTU Solutions purchases, sells, refurbishes and demolishes generation facilities. The company did not disclose the terms of the sale in its statement last week. Dominion announced in 2011 it would close the State Line plant because it would be uneconomic to install environmental controls to meet new federal air emissions standards with power prices weaker due to lower natural gas prices and higher coal prices. State Line consisted of two coal-fired units that generated enough electricity to power about 128,000 homes, using Powder River Basin coal as its primary fuel. The power station ceased operating on March 25, 2012.