All-island blackout Biyagama - Kotmale line was carrying one-third of electricity demand

• It tripped leading to severe under-frequency below limit tolerable by other generators supplying load
• This is the main line transmitting power generated from the key Mahaweli reservoirs
• This line was carrying about 500MW, while the total country’s  demand was around 1500MW

By Kelum Bandara 

With reference to the countrywide power failure, a top engineer said the  transmission line from Kotmale to Biyagama which tripped due to a  lightning strike was carrying about 500MW, while the total country’s  demand was around 1500MW. 

Spelling out technical details, he said the tripping of the line resulted in the loss of one-third of the  supply, leading to a severe under-frequency below the limits tolerable  by the other generators supplying the load. “Consequently, these  generators also tripped, causing an island-wide blackout,” he said.

This is the main line transmitting power generated from the key Mahaweli reservoirs to the load centre in Biyagama.