 Hello everyone, myself Dr. Sunil Lathain Kulkarni, Assistant Professor, Department of Mechanical Engineering, Valchan Institute of Technology, Soolapur. Today I am going to deliver a video session on TERIF Part 1. In this video session, at the end of this video session, students will be able to explain the meaning of TERIF and describe various methods of TERIF. The contents of this video session are definition of TERIF and various forms of TERIF. Now as we know that the electrical energy is produced and supplied to the consumer. So when it is supplied to the consumer, the consumer is charged by using the various methods. Therefore, the TERIF or energy rates are different methods of charging the consumer for consumption of electrical energy. Or it is the rate at which electrical energy supplied to the consumer is known as the TERIF. Now we are familiar with the electrical bill. Every month we pay the bill. So the method in which the billing is made, that is nothing but the TERIF. Now there are various types of consumers, maybe domestic, commercial or industrial. But irrespective of the type of consumer, all types of TERIF methods must cover the following items. First of all, the recovery of running costs such as operation cost, maintenance cost, in which there may be fuel, salaries, wages, etc. Then it should be able to cover the capital cost invested for the power plant. Then it should be also able to cover the cost of metering equipment. Now electrical energy supplied is metered or measured using an electrical power energy meter. Then we need to supply the hard copy of the bills or soft copy and it should be collected. So the cost of metering, billing and collection cost also has to be recovered. In addition to this, the electrical energy production company is an industry which is also supposed to earn a profit. Therefore the TERIF should also have a profit on invested capital. Now the various types of TERIFs have been proposed from time to time. However, they are derived from the general equation Z is equal to AX plus BY plus C where Z is total amount of bill for the period considered. Now this period can be either monthly or it can be annual also. X is maximum demand in kilowatt. Y is energy consuming kilowatt hour during the period considered. A is the rate per kilowatt of maximum demand. B is the energy rate per kilowatt hour that is per unit. And C is the constant amount charged to the consumer during each billing period. Now let us see the various types of TERIF forms. The first and most simple is flat demand rate. Now what is flat demand rate? The flat demand rate is expressed as Z is equal to A into X. That is the bill will depend only on the maximum demand. That is nothing but the X irrespective of the amount of electrical energy consumed. Now it is based on the customers installation of energy consuming devices such as so many kilowatt or HP per month or year. Now you can think for a while that for which type of customer or consumer this type of TERIF is most suitable. Let us pause and let us think for a while. So as we can see that whenever the energy consumption pattern is fixed it is not going to vary particularly in case of street lights. The total street lights usually are on from 6pm to 6am in the morning. So for such a load or even for agricultural load like agricultural pumps irrigation pumps the charging can be made according to the HP of the motor installed. Therefore the bill can be collected once in a year depending upon annual suppose the motor rating is 10 HP and if we charge 1000 rupees or 500 rupees per HP then annually we can charge it as 500 into 10 HP. So it will be 5000 rupees per year. So that is how this flight demand rate can be charged. Now let us see in this type of TERIF the cost of metering equipment and meter rating is eliminated. As we know that we are charging only upon the installed capacity. There is no need to meter or reading record a reading. So no need of taking the reading also and metering is also not required. Therefore this cost is eliminated. Now we can show the flight demand rate on the graphical format Z is equal to A into X. So the value of TERIF Z it is only depending upon the maximum demand. Say X is equal to 1, 2, 3, 4 etc. It is constant irrespective of the electrical energy used that is Y. This is called as a flat demand rate. Now next TERIF method is straight meter rate. Now in this method it is expressed in the form of Z is equal to B into Y. Means it is also one of the simplest form of TERIF. In this method charge per unit is constant. So suppose Y is the number of units which are consumed multiplied by B is the charge. That is amount per unit. Then the charges depend upon the number of units used. But this TERIF has got certain disadvantages. The consumer using no energy will not pay any amount because if suppose somebody is not using electrical energy then Y is equal to 0. So his bill will be 0. However he has incurred some expenses on to the power station. He has connected load to the power station. So if he is not using then power station is generating power which is not getting utilized. So load factor will decrease. Therefore this is not a desirable situation. Since the rate of energy is fixed this method of charging does not encourage the consumer to use more power. Unless the TERIF is very low because if the number of units consumed are more and more and charges are fixed the bill will increase in a straight line meter rate. Let us see the graphical representation of this method. So in straight meter rate the Z that is the TERIF is equal to the bill is equal to B into Y. So number of units increase according to the straight line method the charges will increase. Where Y is the number of units consumed and B is the amount per unit ok charge per unit. So this is straight meter rate. Now the third method is block meter rate. Now what is block meter rate? When a given block of energy is charged at a specified rate and succeeding blocks of the energy are charged at progressively reduced rate it is called as a block rate TERIF or block meter rate TERIF. In block rate TERIF the energy consumption is divided into blocks and price per unit is fixed in each block. For example we will see graphically how this block meter rate is divided. So the price per unit in the first block is highest and it is progressively reduced for succeeding blocks of the energy. And advantage of this TERIF is that the consumer gets an incentive to consume more electrical energy because as the charges with the higher consumption of electricity for higher blocks are less the consumer will be attracted to use more and more electrical energy. So this increases the load factor on the power system and the cost of power generation is also reduced. Now let us see block meter rate. So in this figure you can see the total energy consumption is divided into three blocks. That is Y1, Y2 and Y3 and B1, B2 and B3 are the charges. So here you can see for the first block the charges are B1. For the second block charges are B2 and for the third block charges are B3. So B3 is less than B2 and B2 is less than B1. So we have reduced the successive block charges and total units in the first block are Y1. Therefore the TERIF will be calculated or B will be calculated as for the first block B1 into Y1 number of units into charge per unit for second block B2 into Y2 number of units into charge per second block unit plus number of units into charge per unit for third block B3 into Y3. So accordingly we can calculate. Actually in India the reverse form of this TERIF is commonly used in India. Means as the number of units gets increased the block charges are increasing in India. Now the next two forms are very simple. Two part TERIF for Hopkins and Demand Rate. So when the electrical energy charge on the basis of maximum demand plus number of units consumed it is called as a two part TERIF. So in two part TERIF the total charge is made from the consumer split into two components FIC charges and running charges. FIC charges depend upon maximum demand while the running charges depend upon the number of units consumed by the consumer. Thus the consumer is charged at a certain rate per kilowatt of maximum demand plus certain amount per kilowatt hour of energy consumed. So Hopkins and Demand Rate or two part TERIF is given by Z is equal to AX plus BY where X is the maximum demand plus N is the charge per maximum demand plus number of units into charge per unit. So this is called as a two part TERIF. And the last method is now three part TERIF for duality TERIF. So when the total charge is made from the consumer is split into three parts FIC charge, semifIC charge and running charge it is known as three part TERIF. It is actually modified form of Hopkins and TERIF for two part TERIF. It may be seen that by adding the FIC charge or a consumer charge C to the two part TERIF it becomes the three part TERIF. This type of TERIF is generally used for big consumers. Now let us see the equation for that. It is equal to Z is equal to AX plus BY plus C. So we are just adding some constant charge every month or every year in the two part TERIF so it becomes the three part TERIF. These are the references. Thank you.