‘Hydro plants need to be designed as per Q45’


    Kathmandu, April 10

    Hydropower plants would, from now on, need to be operated in full capacity for five-and-a-half months in a year against existing requirement of five months.

    Amending the Directives on Licensing of Hydropower Projects, the Ministry of Energy has provisioned that the hydropower plants that apply for licence henceforth would need to be designed at basis of Q45 (flow exceedence). This provision is applicable for all projects that supply electricity to the central grid, according to the amended directives. “However, this provision excludes the projects intended for rural electrification (not to be connected to the central grid).”

    The government’s move clearly discourages the high capacity projects, as per the power developers.

    “As the power plants need to be operated for a long period in rated capacity, the developer would have to lower the capacity of plant to ensure full capacity operation for longer period from the available water resources,” said Subarna Das Shrestha, past president of Independent Power Producers’ Association Nepal (IPPAN).

    Earlier, the directives had allowed projects to be designed on the basis of Q40, which meant that projects needed to be operated at full installed capacity for around five months. According to experts, Q40 is the most feasible design for run-of-the-river (RoR) projects.

    Designed at Q40, RoR projects have been easily operating their plants for around five months as the water level rises in the rivers during wet season. However, as they have to operate the plants for longer period, the capacity of  projects would need to be lowered eyeing the hydrological capacity of such projects during dry season.

    The recent move of the government shows that the government would not require more electricity in the wet season in the future. Projects developed at Q40 operate their plants in full capacity during wet season to meet the requirement because water discharge level goes down in snow-fed rivers during dry season.

    According to the Nepal Electricity Authority’s requirement, power plants need to supply only 15 per cent of the rated capacity in the period between mid-December and mid-March and this is the reason RoR-based projects are designed at higher capacity.

    After the revision, capacity of the power plants needs to be readjusted, according to Shrestha. “If we had planned a 200-megawatt project at Q40, capacity of the project will have be readjusted at around 180-megawatt while designing it at Q45 because the power plant needs to be operated for longer period from the available water resources in the river.”

    Private sector developers have said that the government’s move is regressive and unstable because the government had issued the directives on January 4, and then amended it on April 6.

    Source: The Himalayan Times