Categorisation of electricity demand

D15

TANESCO Tariff Categories

Domestic Low Usage Tariff (D1) / This category covers domestic customers who on average have a consumption pattern for 50 kWh. The 50 kwh are subsidized by company are not subjected to service charge. Under the category any unit exceeding 50 kwh is charged a higher rate up to 283.4 kWh. In this tariff category, power is supplied at a low voltage, single phase (230 V).
General usage Tariff (T1) / This segment is applicable for customers who use power for general purposes: including residential, small commercial and light industrial use, public lighting, and billboards. In this category the average consumption is more 283.4 kWh per meter reading period. Power is given at low voltage single phase (230), as well as three phase (400V).
Low voltage maximum Demand (MD) usage tariff (T2) / Applicable for general use where power is metered at 400V and average consumption is more than 7,500kWh per meter reading period and demand doesn’t exceed 500KVA per meter reading period.
High Voltage Maximum Demand (MD) usage tariff (T3). / Applicable for general use where power is metered at 11KV and above.

Tariffs

Domestic Low Usage (D1) / General Usage (T1) / Low Voltage Max (T2) / High Voltage Max (T3) / Zanzibar
Tshs / Tshs / Tshs / Tshs / Tshs
Low Energy(0-50kWh) - per kWh / 49.00
Low Energy(0-50kWh) - per kWh / 156.00
Service Charge per Month / 2,303.00 / 8,534.00 / 8,500.00 / 8,534.00
Demand Charge per KVA / 9,347.00 / 8,669.00 / 4,755.00
Energy Charge per kWh / 129.00 / 85.00 / 79.00 / 75.00

NOTE: All the charges above exclude VAT and EWURA

NOTE: Highest maximum demand rule

Billing Demand (BD) is the higher of kVA maximum Demand during the meter reading period and 75% of the highest kVA Maximum Demand for the preceding 3 months, provided that during the first year of operation the Billing Demand shall be the higher of the kVA Maximum Demand during the meter reading period and 75% of the highest kVA maximum demand recoded commencing from the month the consumer is connected.

Load types such as single phase/three phase

According to TANESCO standards single phase supply ranges from 0–10kW, and three phase supply ranges from 10kW and above. From discussions it was learned that for the purpose of this project we expect to have single phase loads of power greater than 10kW. Most grinding mills are in the range of 20kW – 50kW. In this case TANESCO will have to change the standards of service line construction. This is referring to the cost of material for service line construction.

Load profile

Load categorization and profiles can be obtained but with a mixture of load types. It is not easy to get a load profile or categorize mills or pressors separately. This is because most of the mills and other small machines are part and parcel of the households’ loads.

Possibility to include electrical equipment and/or equipment maintenance

TANESCO normally does maintenance of distributions substation with capacity less than 500kVA but does not go further to customers or end users equipment. For substations with a capacity above 500kVA the customer is the owner of the substation and therefore maintenance work is the responsibility of the owner. TANESCO as well as any other private service companies can be hired to carry out the maintenance at some costs.

Supply of electricity at bulk to certain customer categories

In the discussion of this task it was learnt that supply of electricity at bulk will create double standard tariff in the country in contrary to the existing uniform pan territorial tariff. This will have implication to connection and tariff structure as a whole. Since this can tarnish the image of TANESCO the issue was left pending for Executives to decide. EWURA will be consulted as well.

Isolated electricity distribution networks

For these systems the following loads and customer behaviours will be important to specify before a proper set up of energy service agreements can be designed.

·  Single phase or three phase loads?

·  High voltage or low voltage loads?

·  Loads that can be scheduled to any hour of the day or week?

·  Loads that are tied to for example a few evening hours, or dark hours?

·  Inductive or reactive loads?