Obligation to supply/take supply

From the date of closing down the Board shall be under obligation to supply the licensee, except where prevented by causes beyond its control, and the licensee shall be under the obligation to take from the Board, the whole of the electricity required by the licensee for the purposes of his undertaking, except such quantity of electricity as the licensee may for the time being be entitled under para. III to purchase from a source other than Board or as he may be generating in another station, not being a controlled station.