Turunnya efisiensi Turbin Gas Unit 1 PLTGU Indralaya diduga karena adanya endapan (Pengotor) pada komponen internal Turbin Gas yang mana zat pengotor ini terletak di
bagian kompresor dan turbin. Kotoran, kabut minyak, garam, dan kontaminan atmosfer lainnya dapat mengendap pada bilah kompresor dan turbin selama pengoperasian turbin
gas. Endapan ini secara bertahap akan mengurangi efisiensi termal dan keluaran unit. Endapan ini sebagian besar dapat dihilangkan dan efisiensi yang hilang dipulihkan
dengan pengoperasian Water Washing. Water Washing atau sering juga disebut Water Wash adalah prosedur pengoperasian Nozzle pipa Water Wash yang memang telah dirancang khusus didalam komponen internal turbin gas untuk secara langsung
menyemprotkan air pada sudu-sudu kompresor yang bertujuan untuk membersihkan bagian internal pada komponen kompresor. Setelah Pengoperasian Water Washing selesai, diharapkan efisiensi yang menurun dipulihkan. adapun kenaikan efisiensi dan meningkatnya keluaran daya, akan dibandingkan sebelum Water Washing dan sesudah Water Washing.

The decrease in the efficiency of the Gas Turbine Unit 1 PLTGU Indralaya is thought to be due to deposits (impurities) on the internal components of the Gas Turbine where these impurities are located in the compressor and turbine sections. Dirt, oil mist, salt and other atmospheric contaminants can settle on the compressor and turbine blades during gas turbine operation. This deposit will gradually reduce the thermal efficiency and output of the unit. These deposits can be largely removed and the lost efficiency restored by the operation of Water Washing. Water Washing or often also called Water Wash is a Water Wash pipe nozzle operating procedure which has been specially designed in the internal components of the gas turbine to directly spray water on the compressor blades which aims to clean the internal parts of the compressor components. After the Water Washing Operation is completed, it is expected that the decreased efficiency is restored. As for the increase in efficiency and increase in power output, it will be compared before and after water washing.