Reference no: EM131181562

Question 1:

Two systems of tariff are available for a factory working 8 hours a day for 300 working days in a year.

(i) High-voltage supply at 5 paise per unit plus Rs 4·50 per month per kVA of maximum demand.

(ii) Low-voltage supply at Rs 5 per month per kVA of maximum demand plus 5·5 paise per unit.

The factory has an average load of 200 kW at 0·8 p.f. and a maximum demand of 250 kW at the same p.f. The high voltage equipment costs Rs 50 per kVA and the losses can be taken as 4%. Interest and depreciation charges are 12%.

Calculate the difference in the annual costs between the two systems.

Question 2:
A generating station has two 1000 kW diesel-generator sets. The load is estimated to reach a maximum demand of 2500 kW after two years with an increase of 5.5 ×106 units over the present value. To meet this demand, the following two alternatives are available :

(i) Purchasing one more set of 1000 kW at Rs 400 per kW. The annual interest and depreciation of the new set are 10% of the capital investment. The cost of generation for the station is Rs 75 per kW maximum demand plus 5 paise per kWh.

(ii) Purchasing bulk power from a grid supply at Rs 120 per kW maximum demand plus 3 paise per kWh.

Find which alternative in cheaper and by how much ?