LONDON (Reuters) - Britain's energy regulator said it expects to publish an initial report by grid operator National Grid next Tuesday into what caused disruptive power cuts last week.
An hour-long outage last Friday evening left almost 1 million homes without power while two of London's busiest train stations closed at rush-hour because of overcrowding as services were cancelled or delayed.
Energy regulator Ofgem asked National Grid on Monday for an urgent report interim report into the causes by Aug. 16.
This will be published on Aug. 20, an Ofgem spokeswoman told Reuters.
A final, technical report is due by Sept. 6.
National Grid has said the power cuts were the result of a rare and unusual issue that led to the almost simultaneous loss of output from two generators.
"There have been no near misses nor early warning signs of incidents similar to last Friday's power cuts ... All the time until Friday's events, the system has remained within safe limits," National Grid said in a statement.
"We can and must learn lessons from Friday’s events – however rare their occurrence – as National Grid and as an energy industry," it added.
Separately, an emergency committee will also investigate the incident, the government said this week.
(Reporting by Nina Chestney; Editing by Frances Kerry)
