Grid infrastructure is vital. Without a reliable grid system, electricity supply and other services could be disrupted. But balancing the need for a stable and reliable electricity supply with environmental responsibility has always been a challenge. Tenaga Nasional Berhad’s (TNB) division, TNB Grid, recognises the critical role a stable and reliable electricity supply plays in Malaysia's economic growth and social well-being, as well as how traditional vegetation management practices along transmission line easements often resulted in the clearing of trees and undergrowth to safeguard public safety and grid reliability. While necessary for safety reasons, these practices had unintended environmental consequences.
Clearing vegetation can lead to:
Reduced Carbon Sequestration
Forests play a vital role in absorbing carbon dioxide, a greenhouse gas contributing to climate change. Studies estimate a potential loss of up to 70 tons of CO2 per kilometre per year for high-voltage lines.
Increased Risk of Soil Erosion and Landslides
Forests in hilly terrain, where over 80% of Malaysia's forest reserves are located, offer crucial protection against soil erosion and landslides. Clearing vegetation in these areas can increase the risk of soil erosion and landslides, disrupting ecosystems and damaging infrastructure.
As a responsible national utility provider, TNB Grid considers environment, social, and governance (ESG) elements right from the outset of our planning stages. We are committed to embedding sustainability practices from the ground up within the organisation by prioritising biodiversity conservation.
Balancing Needs with Innovation with Tree Hyperspectral Identification System (THySIS)
Balancing the need for a reliable power grid with environmentally-friendly vegetation management practices along transmission lines is a complex challenge.
This prompted the establishment of the Tree Hyperspectral Identification System (THySIS) - a remote sensing technology, specifically Light Detection and Ranging (LiDAR) and hyperspectral imaging, to identify the flora and fauna in an area as preservation of biodiversity during route selection.
The key benefits of THySIS include:
Compliance with regulations
THySIS empowers TNB Grid to adhere to the Malaysian Forestry Department's requirements by effectively avoiding areas with endangered species during route planning.
Preservation of biodiversity
This system plays a crucial role in safeguarding endangered forest species during the new route selection process.
Enhanced data management
The data obtained from THySIS can be systematically used for line maintenance and future environmental projects.
How THySIS Works:
The key benefits of THySIS include:
- Data Collection: A drone equipped with LiDAR and Hyperspectral sensors flies over the forest canopy.
- LiDAR Sensor Function: Emits laser pulses to measure the distance to treetops, creating a 3D point cloud of the forest, revealing the spatial structure of the trees.
- Hyperspectral Sensor Function: Captures light reflected by the trees across a vast range of wavelengths, creating unique spectral fingerprints for each tree.
- Data Processing: The computer system utilises artificial intelligence (AI) to analyse the combined LiDAR and Hyperspectral data.
- AI Analysis:
a. Utilises LiDAR data to understand the 3D structure and location of the trees.
b. Analyses Hyperspectral data to identify unique spectral patterns of each tree.
c. Combines this information to differentiate between tree species. - Species Identification: Based on the analysis, the AI identifies the specific tree species present in the forest.
- Result Presentation: The identified tree species are displayed on a map or report, allowing for visualisation and further analysis.
Complementing THySIS with a New Approach
Acknowledging the impact of traditional methods has led to TNB Grid overhauling its tree-cutting strategy. This new strategy, introduced in May 2024, incorporates a risk-based approach that works in tandem with innovative technologies like THySIS. The risk-based approach focuses on a thorough assessment of trees near power lines, considering several factors that influence the likelihood of a tree impacting the grid:
Tree Health
A comprehensive evaluation of the tree's health, including signs of disease, decay, or structural weaknesses that could pose a threat to power lines in the event of storms or high winds.
Slope Stability
The location of the tree relative to slopes and potential land movement risks. Trees on unstable slopes, such as those showing signs of erosion or located near past landslides, may pose a greater hazard if they fall.
Hillside Area
Trees located in hillside areas inherently have a higher probability of falling towards power lines due to gravity
By considering these factors, we can further refine our decision-making regarding tree management. This not only enhances the safety and reliability of the grid but also minimises unnecessary tree removal, ultimately preserving our valuable ecosystems. This move highlights our commitment to balancing the need for reliable electricity transmission with environmental responsibility.
Tree Categorisations
TNB Grid manages a total of 13,402 K1 and K2 trees (approximately 44 acres and approximately 536 tCO2e sequestration annually) near power lines. The risk-based tree management approach assigns trees near power lines to one of three categories (K1, K2, K3) based on the thorough assessment considering tree health, slope stability, and location relative to hillsides. The breakdown of each category is as follows:
K1 Trees
These are trees identified as being in the most hazardous condition and pose a high risk of falling onto power lines. They typically exhibit severe signs of disease, decay, or significant structural weaknesses that could cause them to fail even under normal conditions. K1 trees are the highest priority for removal or mitigation.
K2 Trees
These trees are considered to be in a dangerous condition, but less so than K1 trees. They may have signs of disease, decay, or weak limbs that could pose a threat to power lines during severe weather events like storms or strong winds. K2 trees require close monitoring and may be scheduled for removal in the future.
K3 Trees
These are healthy trees that pose a low risk to power lines. They may undergo routine monitoring, but removal is unlikely under the new strategy. K3 trees are typically left undisturbed.
As of May 2024, 6,336 trees (approximately 21 acres and approximately 253 tCO2e sequestration annually) were identified as K1 and K2 (danger trees), including in privately-owned land and those under the purview of the Forestry Department.
Despite not being permitted to cut trees on private properties that pose a threat to power lines, this new strategy, which requires a thorough assessment conducted by qualified Right of Way (ROW) engineers, has seen 4,085 high-risk trees successfully preserved (approximately 14 acres and approximately 163 tCO2e sequestration annually), representing a 100% increase from previous practices.
These preserved trees include those exceeding 100 years old, such as the endangered and protected Chengal (neobalanocarpus heimii) hardwood tree, the Balak (Shorea spp.), and trees that provide vital buffering functions for the ecosystem. This shift in approach not only safeguards our valuable ecosystems but also upholds Malaysia's commitment to biodiversity conservation.
Elevated Transmission Towers
Other than introducing a risk-based approach, TNB is prototyping the use of elevated transmission towers in sensitive ecological areas like forests and nature reserves. These innovative towers boast a taller design that allows power lines to fly over the tree canopy, significantly reducing the need for vegetation removal.
Here are some of the key features of the elevated towers:
| Tower Height | The elevated towers are approximately 90 metres tall. This increased height allows power lines to bypass the tree canopy, minimising deforestation needs. |
|---|---|
| Reduced Environmental Impact | We recognise the importance of minimising environmental disruption during tower construction. Several options are available to reduce our footprint, including:
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The use of elevated transmission towers offers another sustainable solution for balancing the need for a reliable electricity grid with forest preservation. TNB Grid will continue to improve and be transparent in our environmental stewardship efforts by:
- Regularly reviewing and updating our tree-cutting strategy based on learnings and feedback from stakeholders.
- Publishing annual sustainability reports that detail our progress in environmental performance.
- Conducting public consultations on major grid infrastructure projects to ensure community concerns are addressed.
- Investing in research and development to explore further advancements in sustainable grid management practices.
We believe that our innovative approaches offer a promising path towards a more sustainable future for Malaysia's energy sector. By exploring these diverse applications, we can leverage our technology to its fullest potential, ensuring grid reliability while minimising environmental impact.