A 660-MW unit of the NTPC’s plant at Barh in Patna was synchronised with the grid on Sunday morning, which is likely to result in supply of an additional 405 MW electricity for Bihar, a company official said. The unit was successfully synchronised at 9.30 am.The three units that became operational earlier are already successful in generation, and have been contributing over 1,600 MW electricity to Bihar, he said.