What is Emergency source of electrical power requirements in cargo ships as per SOLAS ?

• For a period of 3 h, emergency lighting at every muster and embarkation station and over the sides as required by regulations .
• For a period of 18 h, emergency lighting:
  1. In all service and accommodation alleyways, stairways and exits, personnel lift cars and personnel lift trunks;
  2. In the machinery spaces and main generating stations including their control positions;
  3. In all control stations, machinery control rooms, and at each main and emergency switchboard;
  4. at all stowage positions for firemen’s outfits;
  5. at the steering gear;
  6. at the fire pump referred to in paragraph 2.5, at the sprinkler pump, if any, and at the emergency bilge pump, if any, and at the starting positions of their motors; and
  7. in all cargo pump-rooms of tankers constructed on or after 1 July 2002.
  8. the navigation lights and other lights required by the International Regulations for Preventing Collisions at Sea in force;
  9. on ships constructed on or after 1 February 1995 the VHF radio installation required by regulation, if applicable:
  10. the MF radio installation required by regulation.
  11. all internal communication equipment as required in an emergency;
  12. the shipborne navigational equipment as required by regulation V/12;* where such provision is unreasonable or impracticable the Administration may waive this requirement for ships of less than 5,000 gross tonnage;
  13. the fire detection and fire alarm system; and
  14. intermittent operation of the daylight signalling lamp, the ship’s whistle, the manually operated call points and all internal signals that are required in an emergency; unless such services have an independent supply for the period of 18 h from an accumulator battery suitably located for use in an emergency.
  15. For a period of 18 h one of the fire pumps required by regulation

Note :

In a ship engaged regularly in voyages of short duration, the Administration if satisfied that an adequate standard of safety would be attained may accept a lesser period than the 18 h period.