Power output from the Ramu 1 power station at Yonki has been boosted from 49 Megawatts (MW) to 54 Megawatts (MW) after upgrading of one of the five turbines.

The additional 5 MW of power is the result of a major rehabilitation work done on Unit 5 since November 2013.

Ramu 1 Hydro Power Station has five hydro turbines, three were installed in the 1970s and the other two were installed in the early 1990. PNG Power sees the need to replace the old parts and accessories for all the five hydro turbines.

Most of the old parts have been replaced with new ones by Andritz Hydro, a contractor that is working with PNG Power for the major rehabilitation process.

The new parts and accessories include new governor, cooling system, shaft seal, servomotor (valves), control panels, protection panel, 11kV power cables, Supervisory Control and Data Acquisition (SCADA) control and monitoring system, heat exchangers, flap gate and accumulator.

Rehabilitation work on Units 4 and 5 at the Ramu 1 power station have been completed and the units are in operation while Unit 3 is being upgraded and expected be ready by July, 2014. Rehabilitation work on Units 1 and 2 will begin once Unit 3 is commissioned.

The rehabilitation work began in October 2013 when the drainage pumps in the machine hall failed, resulting in flooding of the power house. In order to fix the pumps, the power station was shut down, affecting power supply to the Ramu grid.

The Ramu 1 Hydro Power Station was shut down again from 16-17 November 2013 so engineers could commence rehabilitation work on unit number 5.

The generator’s draft tube was damaged by the water pressure and required major repairs and the shutdown of the power station was to isolate the generators so that repairs can be done.

Electricity consumers in the Highlands centres, Madang and Lae are advised that there would be power interruptions from time to time for the rehabilitation work.

However, during emergency interruptions, the power supply to these centres would be maintained by the Pauanda Hydro Power Station in Western Highlands and diesel generators at East Taraka, Milford Haven in Lae, Baiune hydro power station at Bulolo and Madang Power House.

Once all the five machines at the Ramu 1 power station are upgraded and in full operation, power interruptions in these centres would be minimized and reliability improved.

Currently the Ramu 1 Hydro Power station is supplying 54 MW from three generators on to the Ramu Grid while the Yonki Toe of Dam supplies 14MW.

They are supplemented by 4MW from the Pauanda Hydro Power station, 10MW from the Baiune Hydro Power station at Bulolo in Morobe Province and a combined thermal generation capacity of 20MW from the diesel power stations in Lae, Madang and the Highlands centres, giving a total generation capacity of 102MW into the Ramu Grid.

This is more than sufficient to meet the demand of 90MW from the Ramu system