( 1 ) THIS batch of writ petitions is by the petitioners who are covered by the category of Large Industrial Power as each one of them has a sanctioned load of mare than l00 K. W. The petitioners have set up installed furnaces for the manufacture of casting and for their factories in Delhi. These furnaces have been set up after having obtained valid licences from the respondent Corporation. For the levy of charges for the supply of electricity there are two systems of tarrif which are followed; one is the flat rate system and the other is known as two part tarrif system. The flat rate is charged on the units of energy consumed while the later system is meant for big consumers of electricity like the petitioners and is comprised of two charges-one minimum consumption guarantee charges, called demand charges and (2) energy charges for the actual amount of energy consumed. It is the later system, that is, two part tariff system which is applicable to the petitioners who are large industrial consumers. Under this system a LIP consumer pays a minimum guarantee consumption charges at the rate fixed by the respondent. If the LIP consumer does not consume quantity of electrici