Sri Lanka’s pursuit of a robust and efficient energy infrastructure is facing a setback, with the completion of the 220 kV transmission line from Kotmale to Polpitiya experiencing significant delays.

This delay, stretching over several years, has not only resulted in operational losses for the State-run Ceylon Electricity Board (CEB) but has also forced the purchase of high-cost petroleum-fired power from private power plants in the southern region, incurring millions of rupees in monthly losses.

To address the challenges in transmitting electricity from the Central Province to the Southern Province, a proposed solution involved constructing a new 220 kV line from Polpitiya to Hambantota and another from Kotmale to Polpitiya. Although the transmission line from Polpitiya to Hambantota has recently been completed, progress on the Kotmale to Polpitiya line has been marred by prolonged delays, with only the foundation being laid.

A senior engineer from the CEB, who wished to remain anonymous, revealed that the estimated cost for completing the 220 kV line would be around Rs. 1.2 billion.

“If this project is already completed, we would not have to purchase electricity from private power plants at a very high cost. They say they purchase heavy fuel-fired power, but the problem is that the costs are equal to diesel-fired power. The delay is due to the lack of funds, but the investment the CEB is making in private power plants could have been easily invested in the completion of the transmission line,” the engineer stressed.

Construction of the line commenced four years ago, but faced delays due to the disruptive impacts of the Covid-19 pandemic in 2020 and subsequent economic crises faced by the country.

The ‘Long-term Transmission Development Plan 2013-2022’ identified the need for a 220 kV transmission connection to Hambantota from New Polpitiya, intending to serve as a transmission highway for hydropower generated at the Mahaweli and Laxapana complexes to reach the southern load centre, ensuring a reliable power supply to the Southern Province.

Despite Sri Lanka’s ambitions to upgrade its ageing transmission line system and enhance connectivity for increased renewable energy integration into the national grid, the current delays pose a risk to expedited projects essential for strengthening the nation’s energy security.

Upgrade needs

The CEB, with the support of international donor agencies and consultants, initiated a survey to identify upgrade needs in the transmission system. Unfortunately, this process came to a standstill due to Sri Lanka declaring bankruptcy.

CEB officials were expecting approval for the resumption of discussions with donors last week. However, despite the receipt of the first tranche of the International Monetary Fund’s Extended Fund Facility, no official approval has been granted, further complicating the path forward.

Sri Lanka’s current network system comprises a 220 kV trunk system and a 132 kV local system. Colombo and its surrounding areas, accounting for 40% of the country’s electricity demand, receive power from hydro and thermal plants. The mesh currents in both the 220 kV and 132 kV systems, along with a single-circuit transmission line, create vulnerabilities, especially during faults (N-1).

Amid a surge in electricity demand and significant developments in electricity generation and renewable deployment, the ongoing development of electricity generation and local transmission lines aims to supply power to consumers in Colombo and other regions.

The Kerawalapitiya TPP and Kelanitissa TPP in Colombo are pivotal in this endeavour, connected to the 220 kV transmission line, transmitting electricity to the mountain side. Power flow dynamics fluctuate, with scenarios of 550 MW flowing to the mountain side and nearly 500 MW from hydro plants like Kotmale to Colombo.

The CEB transmission system, comprising a 220 kV and 132 kV network, interconnected with switching stations, grid substations, and power stations, underscores the need for development and strengthening to meet the growing electricity demand.

New development plan

The latest Long-Term Transmission Development Plan (LTTDP 2015-2024) outlines a 10-year strategy fulfilling network system criteria, including voltage, thermal considerations, N-1 contingency, security, stability, and short-circuit prevention. The plan is a refined version based on the enhanced Long-Term Generation Expansion Plan (LTGEP 2015-2034), divisional medium-voltage distribution plans, and demand forecasts.

In a broader context, the trunk transmission network development plan focuses on understanding imbalances in demand and supply per region, aiming to transport surplus electricity efficiently and sustainably. The study anticipates future needs until the year 2040, emphasising on the avoidance of redundant investments over the 20-year lifespan typical for transmission lines.

The Japan International Cooperation Agency (JICA) Survey Team examined the voltage of the transmission line between Sampoor-New Habarana, crucial for a proposed coal-fired power plant in Sampoor. A comparison of a 400 kV two-circuit tower and a 220 kV four-circuit tower was conducted, aligning with the CEB’s preference for minimising land width.

After extensive analysis, the study noted that most candidate projects of 1-10 MW could be connected with minimal improvements to the transmission network during 2023 to 2026. The grid feasibility for large-scale (above 50 MW) renewable projects during 2023 to 2026 has been determined, with those unable to integrate earmarked for inclusion in the 2027 to 2030 time horizon.

The transmission study suggests that 300 MW of new wind capacity, including 50 MW Stage 2 development from Mannar, could be absorbed with specific transmission infrastructure development at an estimated cost of $ 21 million.

In such a backdrop, when contacted, CEB Chairman Nalinda Ilangakoon told The Sunday Morning that discussions with international donor agencies would resume soon, with the intention of reviving projects previously put on hold due to the country’s financial crisis.

Funding challenges

However, with the country’s financial situation deteriorating, funds committed by the Asian Development Bank (ADB) and JICA for developing the country’s transmission network have been temporarily suspended, owing to the Government’s inability to repay these loans.

The looming challenge is underscored by the need for a multibillion-dollar investment in Sri Lanka’s Renewable Energy (RE) sector to achieve the ambitious 70% RE target. Financing agencies like the ADB and JICA, withholding funds for ongoing projects, casts doubts on future investments in the sector.

In order to meet the Government’s 70% RE target, upgrading the existing transmission line is imperative, requiring a minimum investment of $ 4 billion. Escalating import costs and unpredictable exchange rates might drive the actual cost of transmission line upgrading to around $ 6 billion.