Sam Mackwell founded Mackwell Locomotive Company Ltd in 2016. Today it’s simply known as ‘Mackwell’.

Sam’s pursuit of low-carbon energy began with an early foray into hydrogen. His  early high school experiments resulted in a lot of hot water, a number of loud bangs and a sizeable dent in his parent’s garage roof. From this experience Sam gained a firsthand lesson in the practical difficulties of working with hydrogen as a fuel.

Sam completed his high school education and enrolled in university, however it did not hold his attention for long. Instead, he led his own career path directly towards developing a zero emissions ‘turbine’ engine. The prototype was successful but the engine relied on liquid or gaseous biofuels with a low energy return on investment (Energy-ROI). Sam realised that biofuel production was flawed and an inefficient use of land. The technology wasn't making biophysical sense and so the project was put aside, but important lessons were learned.

At this time Sam had begun working on heritage railways in Christchurch to learn more about steam dynamics. One local railway in Christchurch sourced its entire fuel supply from firewood grown and harvested on site. The relative ease and cost effectiveness at which this century old technology could convert biomass into mechanical power impressed Sam and he directed his attention to exploring this unique combination of biomass and steam.

Sam discovered that the energy yield per unit area of land for biomass was up to 10 times higher than for liquid biofuel crops. Trees are unrivalled in their ability to capture and store the sun's energy with very little support or processing. In its solid form, biomass has an incredibly  high Energy-ROI of 25:1.