Sri Lanka in extended blackout as grid fails repeatedly – Update
ECONOMYNEXT – Sri Lanka’s power blackout which started around mid-day has extended towards nightfall as grid failed repeatedly while engineers were attempting to restore power, Ceylon Electricity Board officials said.
The cascading failure was suspected to have been triggered by a transmission line failure in the Kerawalapitiya area.
But attempts to restore the grid had failed repeatedly, with supply fluctuating and de-stabilizing frequency and voltage. Frequency had been surging above 51 Hz at times.
The instability of supply, industry officals now suspect, could have come from solar power, which the CEB’s system control cannot dispatch.
The grid was gradually restored after sundown.
CEB had earlier warned about the share of power coming from multiple small plants plants which could not be dispatched centrally, leading to system instability, when the share of small plants and rooftop solar increases.
Powergrids are designed to distribute power in one direction, but there is heavy lobbying to accommodate small renewable plants on an ad hoc basis, without the existence of a distributed grid, industry analysts say.
The CEB itself is building a renewable park in Mannar with facilities to handle intermittent power (see variable renewable power) and can also be dispatched (switched on or off by systems control).
The grid usually maintains frequency and voltage by adjusting a large hydro generator.
Power was restored to the South of the country, which has been isolated from the national grid, early.
The Southern grid was energized by the Samanalawewa hydro power reservoir.
Cascading power failures are not common in Sri Lanka and the last was in 2016.
While a grid can come down fast as sections of the transmission line trips, forcing generators to also trip, it is more difficult to restore power.
Power demand also go up in the night. (Colombo/Aug17/2020 – Updated)