The power charges in common areas are automatically calculated and distributed between the consumers based on per floor area. The data entry consists of No. of slabs, Slab rates, Fixed charges, miscellaneous charges, Tax percentage, Special instructions, etc. Energy Meters are used for recording the power consumption. The consumption of Electricity is recorded in terms of kWh (Kilowatt Hour) also called as units. One Kilowatt Hour is equivalent to running an appliance of 1 Kilowatt (or 1000 Watts) for 1 hour. Also 1 KWh is considered as 1 unit Consumed while billing of the energy consumed. The units consumed are calculated by observing the readings and then they are applied to a slab based tariff structure to come up with energy or electricity charges. The tariff structures for residential consumers are designed in such a way that per unit charge is less if your consumption is less and more if your consumption is more. So the power charges increases significantly if you consume more electricity. For example, the tariff method used in Tamilnadu is shown in the Fig.1.
For instance if you have consumed 600 units in a month, your bill will be calculated as:
First 100 units @ Rs 1.50= Rs 150
Next 200 units @ Rs 3.00= Rs 600
Next 200 units @ Rs 4.60= Rs 920
Final 100 units @ Rs 6.60= Rs 660
From the above example it can be clearly depicted that if you consume more electricity then the charges also increases correspondingly based on a fixed tariff. The main intention behind this structure is to propel people to consume less electricity. Every state has different categories that cater to the needs of the businesses prevalent in their states. But the most common categories are domestic (residential), commercial (shops and offices) and Industrial (manufacturing units). With rates being lowest for residential consumers and highest for industrial consumers. Within these categories there are separate rates for LT and HT. So if we have to list down, following categories will be available in most states:
Domestic-LT: for most individual residential connections.
Commercial-LT: for small shops and offices. Also for hotels, guest houses, theaters, etc.
Industrial-LT: for very small manufacturing units (like bakery, stone cutting, mills, etc.).
Domestic-HT: Bulk supply for residential colonies.
Commercial-HT: for bigger offices, film studios, etc.
Industrial-HT: for most heavy industries.
Many a times the categories are also differentiated depending on the connected load and the tariffs increase if the connected load is higher.
A sample HT bill of the Kerala state EB is shown in the Fig.2.