GMTC's input fuels are mainly natural gas, fuel oil, and diesel. Natural gas and fuel oil are used in boilers and heat treatment furnace. The total fuel consumption of the Company is 1,635,790 GJ, and natural gas accounts for 96%; the indirect energy is entirely external energy. For electricity purchased, the Company's total calorific value of energy consumption was 671,625 GJ, and grid electricity accounted for 100%.

The consumption of various energy sources in the major processes in 2023: Electricity, 185,226 thousand kilowatt-hours; Natural gas, 41,613 thousand cubic meters; Fuel oil, 1,277 kiloliters; and Diesel, 541 kiloliters. The calorific value of each energy source is shown in the figure, and the proportion: natural gas, 68%; electricity, 29%; fuel oil, 1%; and diesel, 2%; the energy intensity of the major processes is 27.90 GJ/metric ton, an increase of 4.80% over the previous year. In the second quarter of 2023, the old rotary furnace was eliminated, so the proportion of calorific Value from fuel oil dropped from 7% in 2022 to 2% (see the 2022 Sustainability Report for details). In addition, the production volume decreased in 2023 due to the change in product mix but the energy intensity has increased.

GMTC established the ISO 50001 energy management system, while its Xinying Plant and Liuying Plant each set up energy audit and management teams to continuously monitor energy consumption, and formulate energy-saving plans to promote various measures with the aim to reduce energy consumption in each unit and mitigate the negative environmental impact. The annual energy saving target of the two factories is set at 1%. The Xinying Plant achieved an energy saving performance of 5.46% in 2023, with an average energy saving rate of 2.16% between 2015-2023, and Liuying Plant's energy saving performance in 2023 was 1.00%, with an average energy saving rate of 0.87% between 2015-2023.

GMTC actively cooperated with the Tainan City Government on the project of building a "Solar City of Tainan", with green energy schemes for the low-carbon city. Since 2012, we have cooperated to complete rooftop solar power generation installations on the roofs of the Xinying and Liuying Plants to make optimal use of the factory space and increase the thermal insulation effect of the factories. As of 2023, the total installed capacity was 3,158.03KW.

In 2023, the cumulative power generation totaled 2,195.047 kilowatt-hours, and the carbon reduction was about 1,087 metric tons (calculated in 2023 based on the annual electricity emission coefficient of 0.494 kg/kWh announced by the Bureau of Energy in 2023)