If the consumer having own generating set(s) can have, a result of additional generation reasonable in the opinion of the Divisional Engineer of the Board having jurisdiction, energy, surplus to his requirement, the Divisional Engineer may direct him to supply the surplus to the Board or to another consumer nearby who has been taking supply from the Board and who is willing to take the supply from the consumer having generating sets: Provided that (i) the contract demand of and the supply to the other consumer from the Board shall be reduced correspondingly, whether or not the other consumer avails of the supply from the consumer having the set, (ii) the other consumer shall pay to the consumer having generating set(s) for such supply as if it is supplied from the Board, (iii) if the payment receivable by the consumer having the set under the last preceding clause is less than his incremental cost of additional generation, the Board shall make good the difference to the consumer having the set(s) and (iv) the consumer having the set(s) will not be required to incur any additional expenditure for laying lines for transmitting energy to the other consumer; such lines if required being laid by and at the cost of the Board.