Thursday, September 27, 2007

Wind, sun and diesel



Villagers on an East Coast island are shrinking their carbon footprints by buying green energy.

THE two giant “fans” rise grandly from the highest point of Pulau Perhentian Kecil, Terengganu, their manmade presence in sharp contrast to the lush greenery. Up close, the two white edifices are even more awe-inspiring, their three blades cutting through the air with ominous resonance.

The fans are power-producing wind turbines – the first in the country – and are part of a unique solar-wind-diesel hybrid power generation system. Installed by Tenaga Nasional Berhad (TNB) and allegedly the first of its kind in Asia, the hybrid system has a combined capacity of 650 kilowatts (kW), and is made up of two 100kW wind turbines, 100kW worth of solar panels as well as two diesel generators capable of 200 and 150kW respectively.

It also includes a battery that can store up to 480kWh (kilowatt hour) of power.

TNB Energy Services managing director Rahimuddin Baharudin says the hybrid system will cut the cost of generating power on the island by almost 40% from the previous diesel generator system.

“Before TNB came to the island, the villagers relied on their own small generators. In 2002, TNB installed a diesel generator that powered the island for 24 hours. However, with rising diesel prices, we had to find a way to reduce the cost of generating power. One of the ways is to use renewable energy generated by wind and sun.”

At this stage, the hybrid system is not meant to replace the diesel generators but to minimise the usage of diesel as a source of electricity. The combination of solar panels, wind turbines and diesel generator will ensure a continuous flow of electricity no matter what the weather conditions are.

“In the day, when we have less wind, the solar panels will cover the extra load. At night, the wind turbines will be the ones generating more power. If the solar panels and wind turbines do not create enough power, the diesel generator will (automatically run to) compensate for the deficiency.”

Rahimuddin says the system has worked well so far, to the extent of generating excess energy that has to be burned off with a heater. For now, the hybrid scheme only provides electricity for Kampung Perhentian on Pulau Perhentian Kecil, and not the dozens of resorts that pepper the sandy shores of neighbouring Pulau Perhentian Besar. The reason? The project comes under the Government’s rural electrification project and is meant for domestic usage only.

Rahimuddin reckons that it is technically possible for the resorts to tap the renewable electricity since there is now excess power. The resorts currently run their own diesel generators.

Project inception

Rahimuddin explains that Terengganu Mentri Besar Datuk Seri Idris Jusoh was eager to have a renewable energy system on the island after learning about TNB’s solar hybrid schemes in places such as the Pemanggil, Aur, Sibu, Besar and Tinggi islands off Johor, and Kampung Denai in Rompin, Pahang.

"He has also seen wind farms in Europe and asked us about the possibility of building wind turbines on Pulau Kapas and Pulau Perhentian. At the time, we were aware that Pulau Perhentian has plenty of wind but whether we could harness that energy was a different matter altogether.

“We had done a study in the area from 1993 to 1999 using a wind monitoring station. But when we started researching this project, we found that the data was outdated. The global climate has changed so much, thanks to global warming, that sometimes we get wind at the wrong times.”

TNB took six months to reanalyse the data and design the system, and another six months to build it. The State Government, TNB and Federal Government each funded one-third of the RM12.76mil cost.

The turbines are designed to harness the winds on Pulau Perhentian as efficiently as possible. Sensors on the structures analyse wind directions and speeds, and the turbines will automatically turn to face the wind.

The entire system is remote-controlled via the Global System for Mobile communications (GSM) satellite from TNB’s headquarters in Kuala Lumpur. A few employees are onsite to conduct maintenance on the diesel generator.

“Most of our solar hybrid stations in Johor and Pahang are unmanned. But this particular system needs someone to look after the diesel generator at all times,” says Rahimuddin.

Installation of the wind turbines by contractor Wazlina, was planned carefully to minimise the environmental impact on the island, according to Rahimuddin. “We were given conditions by a committee comprising relevant authorities like Marine Department and Department of Environment.”

Wazlina environmental consultant Shan Suleiman says although the worksite was considered only a “small footprint” on the island, they minimised the impact by not cutting trees unnecessarily, building silt traps and monitoring siltation caused by earthworks.

However, bringing equipment and materials to the island posed problems. “The transportation was controlled by the Marine Department. Whenever we had a barge coming in, we had to report to them and could only bring the barge in at certain high tides,” says Wazlina director Mohd Safian Dato’ Salleh. “In the end, it cost us almost three times the normal amount to bring in the equipment and materials from the mainland.”

Despite the higher cost of producing the renewable energy, Pulau Perhentian Kecil villagers are still charged the same electricity tariffs as on the mainland. This differs from the recently launched solar-hybrid system on nearby Pulau Kapas. There, TNB merely built the system. A state-appointed body sells the electricity to resorts at whatever cost they see fit. “The electricity is sold according to the production cost, plus the profits for the body running it,” explains Rahimuddin.

No comments: