Method of starting and operating a shape memory alloy heat engine

A method of starting and operating a shape memory alloy (SMA) heat engine having a first rotatable pulley, a second rotatable pulley, and an SMA material disposed about the first and second rotatable pulleys and between a hot region and a cold region, the method comprising:

• detecting a thermal energy gradient between the hot region and the cold region using a controller;
• initiating movement of the SMA material using an electrical generator coupled with one of the first and second rotatable pulleys;
• decoupling the electrical generator from one of the first and second rotatable pulleys following the initiation of movement;
• monitoring a speed of the SMA material about the first and second rotatable pulleys;
• re-engaging the electrical generator if the monitored speed of the SMA material exceeds a threshold;
• and
• wherein the SMA material is configured to selectively change crystallographic phase between martensite and austenite, thereby converting the thermal energy gradient between the hot region and the cold region into mechanical energy.