We have characterised a small, high-efficiency diesel generator selected to power remote experiments on the Antarctic plateau at altitudes of up to 5000 m. We describe the design of an environmental chamber to simulate these high altitudes and present an experimental investigation of the engine operation at high altitude on Jet A-1, comparing this to the engine's performance at sea level. Although attention must be paid to the provision of adequate cooling, no modification to the engine itself is required. Our final system provides very high reliability and produces 1500 W of electrical power with a fuel consumption of 280 g kWh⁻¹. A bank of ultracapacitors is used to start the engine in the cold environment of Antarctica. We describe the low-temperature operation and survival tests that we performed on the ultracapacitors and the engine.