Committee on Climate Change (CCC) has concluded that there is scope for the penetration of renewable energy to reach 30 - 45% of all energy consumed in the UK by 2030.The fuel cell technology at ZEM has the potential to supply auxiliary power units in Kilowatt scale by 2026. Some applications of the auxiliary power units in the maritime sector  is cold ironing. Cold ironing is the supply of electric power to water vessels while stationary (main engines switched off) allowing for refrigeration, heating, lighting, emergency equipment operation while loading and unloading. Our portable auxiliary power units have zero carbon emissions while supplying electricity. Auxiliary power units can be also used onboard of vessels during their operations in the water to replace or complement existing units.