At least where I live, the Steam is either reused from thermal power plant waste heat which would be evaporated off anyways, or its the heat directly produced f

At least where I live, the Steam is either reused from thermal power plant waste heat which would be evaporated off anyways, or its the heat directly produced from specialised combined electric/thermal gas plants (Blockheizkraftwerk). Also, general industrial waste heat is sometimes used (glass plants e.g).