In an amendment to current North Dakota law, environmental upgrade equipment used in power plants or for repowering existing power plants that began construction after June 30, 1991 is exempt from sales and use tax. An “environmental upgrade” is defined as “an investment greater than twenty-five million dollars or one hundred thousand dollars per megawatt of installed nameplate capacity, whichever is less … for reducing emissions or increasing efficiency at an existing power plant.” These changes to the existing law are effective after June 30th, 2005. (North Dakota H.B. 1268, Laws 2005)