The Beale engine is usually used for electrical generation - via a linear alternator. This one made by Julian Wood has now been refurbished to drive a water pump by Dennis Cowdery.
The engine is called a Free Piston Stirling Engine - FPSE - because the piston and displacer are not linked to any crank mechanism. They oscillate freely.
They are used quite widely for electricity generation - see Qnergy.com (not Qenergy) who make 3.5 kWe and 7.5 kWe engines.
The other way round - when driven by the linear motor - minus 100 degrees C is obtained by TWINBIRD of Japan
This video brought to you by Stirling Engine Society members!