* Imposes 2-1/4-hour daily power cut
* CEB says Chinese power plant not up to standards
* Drought reduces hydro power generation by 85 pct
COLOMBO, Aug 13 (Reuters) - Sri Lanka's state-run power firm said on Monday it had extended nation-wide daily power cuts by a fortnight due to repeated technical problems at a Chinese-built power plant which has knocked out almost a fifth of the island's generating capacity.
The extended power cuts come as Sri Lanka has lost almost 85 percent of its hydro power generation capacity due to a drought.
Sri Lanka imposed power cuts in July for the first time since 2001 after the Chinese-built coal power plant at Norochcholai failed for a fifth time since it was commissioned in March last year.
The state-run Ceylon Electricity Board (CEB) later repaired the 300 megawatt (MW) plant, but another technical failure has forced the utility to again turn off electricity for two hours and 15 minutes daily.
"In our opinion, it has not been performing up to the standards and up to the expected level," Anura Wijepala, CEB's deputy head told reporters referring to the country's only coal-fired power plant.
"Unfortunately all our efforts to restore Norochcholai power plant have not been successful. It needs about two weeks shut down for the repairs."
China has loaned $450 million for the first phase of the coal plant and another $891 million for the second phase, which is due to be completed by July 2014 when the plant is expected to generate 900 MW.
With the coal plant failure, Sri Lanka has lost 17 percent of its capacity to meet peak demand of 1.79 gigawatts (GW), CEB said.
In January, CEB's Technological Engineers Union blamed a Chinese firm for repeated technical failures at Norochcholai, say they were either caused by sabotage or negligence by the operator.
Sri Lanka has long maintained uninterrupted power supply, one of its main pledges to voters and investors, except in 1996 and 2001/2 when it endured power cuts due to severe droughts.
On Friday, Sri Lanka's Power and Energy Minister Champika Ranawake told the parliament that the power shortages could worsen if annual monsoon rains do not arrive by mid September.
Sri Lanka has total electricity generating capacity of 3.1 GW, but hydro power's normal output of 1.2 GW has been cut by more than 1 GW due to the latest drought. (Editing by Jeremy Laurence)