STIRLING ENGINE

An external combustion engine in which heat is applied through the wall of a chamber within which a gas is successively heated and cooled, alternately expanding and contracting to power a piston inside the chamber. Its advantages include: exceptional silence, lack of vibration, long life, high efficiency , extremely low emissions and adaptability to many different kinds of fuel. Its main drawbacks are the need for extremely effective seals, inflexible control systems, and cost.