Why was the thermal efficiency of the Paris gas turbine of 1903 so low?

The low thermal efficiency of the 1903 Paris gas turbine was primarily due to the technological limitations of the era regarding component efficiency. In a gas-turbine engine, overall performance is heavily dependent on the efficiency of both the compressor and the turbine.1

Historically, the development of the gas turbine was significantly delayed by the difficulty of designing efficient compressors. Early gas turbines utilized centrifugal compressors, which were simple but limited to low pressure ratios and could not achieve the high efficiencies seen in modern axial-flow designs. Because the compressor and turbine in early units were not sufficiently efficient, a large portion of the power generated by the turbine was consumed just to drive the compressor, leaving very little net power and resulting in poor thermal efficiency.12

Furthermore, thermal efficiency is fundamentally linked to the turbine-inlet temperature. Early engines lacked the advanced high-temperature materials and blade-cooling technologies necessary to operate at the high temperatures required for high efficiency. Without these capabilities, early gas turbines could not compete with the thermal efficiency of reciprocating internal-combustion engines of that time.1345