http://www.yokogawa.com/success/

Executive Summary

PT PLN is a government-owned company that

manages the electric power industry in Indonesia. To

ensure a stable power supply for North Sulawesi

province, PT PLN has built and currently operates four

geothermal power plants in Lahendong, which is

located 30 km south of Manado, the provincial capital.

The two newest plants, Lahendong III and Lahendong

IV, each produce 20 MW of electricity, and the

financing for their construction was provided by the

Japanese government’s Official Development

Assistance (ODA) program and the Asia Development

Bank (ADB), respectively.

Indonesia’s economy is growing at a remarkable rate,

and the country’s demand for electricity far outstrips

supply. Despite holding 40 percent of the world’s

geothermal reserves, enough to produce about

30,000 MW, the country has done relatively little till

now to make use of this resource. However, the

Indonesian government has signaled a strong

intention to begin developing the country’s geothermal

resources.

Geothermal energy is a clean and renewable power

source, and plants of this type produce extremely little

, which is a major contributor to the greenhouse

effect. For this reason, efforts to make use of this

resource are gaining momentum, and its development

is expected to bring great environmental and

economic benefits.

At the Lahendong III geothermal power plant,

Yokogawa installed the CENTUM CS 3000 distributed

control system (DCS) with redundant controllers, a

backup system, and a test system. Based on the

success of these installed systems, Yokogawa

subsequently received an order to install its CENTUM

VP DCS at the Lahendong IV geothermal power plant.

Then, when carrying out a project to renovate the 20-

MW Lahendong I plant in the ensuing year, PT. PLN

selected the CENTUM VP to replace the existing

Bailey INFI 90 system that had been used to monitor

and control the steam turbine auxiliary facilities as it

was approaching the end of its useful life. The solid

performance of the systems used, combined with

Yokogawa's superior technical expertise in

geothermal power generation, the proven quality of its

products, and its extensive engineering and service

network in Indonesia, were primary considerations in

PT. PLN's decision to go with the CENTUM VP

solution again.

Ensuring Safe and Reliable Operations at PT PLN

Lahendong I, III and IV Geothermal Power Plants

Location: Lahendong, North Sulawesi, Indonesia

Order date: 2007 (Lahendong III), 2010 (IV), 2013 (I)

Completion: 2009 (Lahendong III), 2012 (IV), 2014 (I)

Industry: Renewable Energy (Geothermal Power)

The Challenges and the Solutions

Automated plant and turbine startup and

shutdown

Plant and turbine startup and shutdown procedures

are very complex and time-consuming, and place

great stress on both personnel and equipment. To

eliminate operator errors during these critical

processes, the CENTUM DCS has automated plant

and turbine startup and shutdown procedures. The

startup and shutdown sequences are executed in

accordance with the logic design, and the DCS human

machine interface (HMI) clearly shows the status of

the sequence and the facility conditions. It also guides

operators in the acknowledgement of messages and

alarms and the triggering of interlock sequences.

Operator intervention during the automated plant and

turbine startup and shutdown processes is minimized,

ensuring safe and smooth startup and shutdown. This

greatly reduces operator workload and errors,

shortens the startup and shutdown times, and

mitigates thermal and physical stress on the turbine.

Success Story – Ensuring Safe and Reliable Operations at PT PLN Lahendong I, III and IV Geothermal Power Plants

ISD-SP-R193

Automatic turbine startup window

Startup procedure window

Graphic of turbine system

Central control room