Steam would be a Steady and Sturdy source of power, as the components could survive the pole shift. Steam might also be used as a Supplemental power source, or Secured from geothermal sources. Steam Engines require a Distiller, so a byproduct of steam is Distilled Water, another Aftertime necessity when surface waters will often be polluted with volcanic ash fallout. BTU's can be computed. The Factors considered include steam being Cost Efficient and its many Applications. Steam engines can be Purchased. Steam Turbine designs are also available. The Internal Combustion engine (Car Parts, 4 Stoke, Pistons and Lubrication) could be modified. Converted Water Heaters should not be used for this purpose. Manufacturers of Commercial Boilers are a source of components. Coils as a boiler can maximize heat from a source. Those unfamiliar with steam should be forwarned that it is Invisible, and quite hot and dangerous, as explained in this Backwoods Home article! A Troubled Times TEAM is exploring the use of steam during the Aftertime.