The photo is sourced from new-media.dhakatribune.com
The construction of the TPP worth a total of $4.8 bln (51,855 crore Bangladeshi taka) began in March 2020. The project is remarkable for its use of an “ultra-supercritical” technology of power generation that makes it possible to save on coal when generating electricity. This is a technology of coal-fired TPPs whose classification depends on the water heating temperature (during coal combustion) required to produce vapour and subsequently transform it into electricity. The benchmark here is the critical water point, which is reached at the temperature of 374 degrees Celsius and the pressure of 218.5 atm: these conditions dissolve the differences in physical properties between liquid and vapour.
Accordingly, the water heating limit for “subcritical” coal-fired TPPs is 374 degrees Celsius, whereas this indicator stands at 566 degrees Celsius for “supercritical” TPPs and 760 degrees Celsius for “ultra-supercritical” ones respectively. The higher the temperature, the higher the efficiency of transforming thermal energy into electricity: the World Coal Association estimates that, while the efficiency is 33% for “subcritical” coal-fired TPPs, it can reach 44% for “supercritical” ones and about 50% for “ultra-supercritical” ones.
Coal is the third leading source of electricity generation in Bangladesh. According to Ember research centre, the share of coal-fired TPPs in the country’s energy mix stood at 12.6% in 2021, whereas the share of gas-fired power plants was 68.2% and that of power units based on fuel oil and diesel fuel was 17.5% (with all other sources accounting for 1.7%). By January 2023, there were four coal-fired TPPs with an aggregate capacity of 2.9 GW in operation in Bangladesh.
