The contribution of hydropower to the national grid dropped to 22.7% as of Thursday (7), raising concerns about the preparedness of the State-run Ceylon Electricity Board (CEB) to cope with a potential further decline in hydropower generation due to the ongoing dry weather conditions.
As predicted by the Meteorology Department, the prevailing dry weather conditions are expected to last until the end of this month, while the department expects considerable rainfall in April.
However, if current dry weather conditions continue in the same vein, the existing hydro resources will be further depleted, ultimately creating a hydropower deficit in the national grid.
In accordance with the decisions reached during the weekly operational meeting held on 28 February for the week spanning 4-10 March, as facilitated by the Water Management Secretariat at the Mahaweli Authority of Sri Lanka, specific directives have been outlined.
These include the resolution to curtail the water release from Samanalawewa and to maintain an average release of 0.75 million cubic metres per day (mcm/day) from Upper Kotmale.
Additionally, there is an agreement to release an average of 2 mcm/day from Polgolla while minimising water discharge from Kotmale and Rantambe during this period.
In this backdrop, Power and Energy Ministry Secretary Sulakshana Jayawardena told The Sunday Morning that there would be no deficit in the national grid due to the decline in hydropower generation as CEB thermal, coal, and oil power plants would be utilised to generate more thermal power.
“We are in the process of looking for supplementary power options to cut down the expenses. In the event the CEB thermal oil options cost more than the supplementary power bids, the CEB will go ahead with purchasing supplementary power,” he explained.
Power generation stats
As of Thursday (7), hydropower, led by the Laxapana Hydro Complex, Mahaweli Hydro Complex, and Samanala Hydro Complex, contributed 22.70% of total energy. Conversely, thermal sources, primarily CEB thermal coal, dominated with a substantial 38.90% share.
While renewable sources like wind, solar, biomass, and mini hydro collectively contributed 12.20%, their individual percentages remained relatively modest. Notably, SPP solar stood out with a 7.40% contribution. The day’s total energy generation reached 50.09 GWh.
The combined contribution of CEB oil and IPP oil to the national grid from thermal oil sources was 13.12 GWh. This indicates the total energy generated from oil-based thermal sources, with CEB oil contributing 7.43 GWh and IPP oil contributing an additional 5.69 GWh.
Also, as of Friday (8), the status of major reservoirs reveals a mixed scenario. While Castlereigh, Maussakalle, Kotmale, Victoria, and Randenigala have maintained stable water levels with no recorded rainfall in the past 24 hours, Samanalawewa experienced a modest precipitation of 9.50 mm during the same period.
The statistics from the Mahaweli Authority reveal the active effective storages of Kotmale, Victoria, Randenigala, Rantembe, Bowatenna, Moragahakanda, and Kalu Ganga, which stand at 63.3%, 81.2%, 87.6%, 76%, 30.5%, 90.7%, and 99.9%, respectively.
However, the active effective storages of Castlereigh have dropped critically to 7.4% and Maussakele is recorded at 61.6%. Samanalawewa maintains an active effective storage of 76.3%, while Udawalawe has reached spill level.
Additional power needs
With hydropower experiencing a declining trend, concerns have been raised over the CEB’s financial allocations for the procurement of supplementary power and the possible impact of such procurements on the next tariff revision. Concerns abound on whether any fluctuation will result in a raise in electricity tariffs.
The CEB is reportedly incurring substantial monthly expenses in capacity charges for the emergency power acquired last year, amounting to millions of rupees.
Despite the emergency power plants yielding an average monthly generation of only 6.29 GWh, the CEB is obligated to pay an average monthly capacity charge of Rs. 206 million for the procured power plants.
The urgency for additional power arose from the depletion of the Samanalawewa Reservoir linked to the Udawalawe Reservoir, prompting the CEB to obtain 120 MW of emergency power from Ace Power Embilipitiya (100 MW) and Matara (20 MW).
Concerns have been raised over the inclusion of this emergency power in the CEB’s dispatch forecast, particularly without approval from the Public Utilities Commission of Sri Lanka (PUCSL).
The PUCSL has sought clarifications from the CEB regarding the inclusion of 100 MW of emergency power in the dispatch plan, expressing reservations about the proposed purchase of additional emergency power in 2024.
The previously-anticipated 4,500 GWh of hydropower generation for 2023 by the PUCSL and the CEB was reduced to an estimated 3,750 GWh as a result of the severely-affected rainfall patterns in the country due to the drought which began in July 2023.
Furthermore, as per the approval of the Cabinet, the electricity tariff that existed until then had to be increased by 18% from 20 October 2023, as emergency supplementary thermal power had to be procured due to the urgent need to release water from the Samanalawewa Reservoir for agricultural purposes.
Speaking to The Sunday Morning, a senior CEB official who wished to remain anonymous said that if the board had procured sufficient amounts of renewable energy such as solar and wind, it would not have had to opt for expensive thermal oil or supplementary power.
Also, as reliably learnt by The Sunday Morning, the supplementary power purchasing request is yet to be submitted to the PUCSL. The CEB is still in the process of finalising the decision on supplementary power, it is learnt.
In such a backdrop, a senior CEB engineer noted that the procuring of supplementary power should have been conducted following a thorough evaluation and in advance in order to obtain the cheapest prices without waiting until the last moment.