Transcript Electricity Pricing

Electricity pricing
Tariffs
Tariffs
• Definition:
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Different methods for charging
consumers,
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Rate of payment for consumption of
electricity
Some basis
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Purely on Total energy (kwh) consumption
Maximum demand and total energy consumption
Amount of energy consumed
Power factor of the load
Time at which the load is required
Type of the customer ( Industrial , commercial or
residential )
• HT (High voltage) & LT customers
Some basis
• Purely on Total energy (kwh) consumption
Flat rate tariff
• Maximum demand and total energy consumption
Two part Tariffs
• Amount of energy consumed
Block rate Tariff
• Power factor of the load
Power factor Tariff
• Time at which the load is required
Time of the Day Tariff
Some basis
• Type of the customer ( Industrial ,
commercial or residential )
• HT (High voltage) & LT customers
Industrial consumers
• Basis of charging Industrial consumers is
generally Two part tariffs;
• One part of charge is proportional to the maximum
demand ( kilowatts) because this affects the size of
the plant to be installed and corresponding fixed
charges on capital.
• The second part of charge is proportional to the
energy consumed (killowatt-hours) monthly or
annually.
Residential consumers in Early days
• In early days policy was to induce
customers to use more energy, some
companies used two or more flat rates
• First few kwh are charged at certain rate,
the next few at a lower rate, next few at a
still lower rate and so on.
Residential consumers Now a days
• Due shortage of generation Now a days
policy is to discourage customers to use
more energy, some companies use two or
more flat rates
• First few kwh are charged at certain rate,
the next few at a higher rate, next few at a
still higher rate and so on.
Incentives and penalty
• Consumers taking off peak power Special cheap
rates to help to improve the load factor of the
system.
• Consumers whose pf falls below a specified limit
may be charged more; have a penalty clause in
the rate structure.
• Alternatively the consumers may be charged on
combined killovolt-ampere-hour ( kVA) and
killowatt-hour (kwh)basis.
Modern techniques
• Electricity Regulatory commission ( ERC)
governs the fixation of tariffs for various
Consumers.
• The rate structure should be arranged so as
to help the system to have better load factor
and power factor so that electrical energy
can be produced and sold more cheaply.
Energy supplied to consumers
kwh generated
G
Kwh loss in
transmission
kwh Received
kwh used by station
auxiliaries
Energy to consumer = kwh generated – kwh used by aux – kwh loss in transmission
Some Examples
• 2.9 (mvd)
• Apower station has a installed capacity of 20000 kw , the
cost of the station is rs 1200, per kw . The fixed costs are
13% of the cost of investment. On full load at 100% load
factor, the variable cost of the sttio per year are 1.5 times
the fixed costs.Assume that there is no reserve capacity of
the plant and that the variable cost are proportional to to
the energy production Find the cost of generation per kwh
at load factors of 100% 80%, 60%, 40% and 20% and plot
the curve. (ans Load fctors and cost per kwh; 100% 4.46p
,; 80% 5.65p; 40% 7.15p; 20% 11.5p)
Some Examples
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2.10 (mvd)
Apower station has a installed capacity of 20000 kw , the cost of the station is rs 1200, per kw . The
fixed costs are 13% of the cost of investment. On full load at 100% load factor, the variable cost of
the sttio per year are 1.5 times the fixed costs.Assume that there is no reserve capacity of the plant
and that the variable cost are proportional to to the energy production Find the cost of generation per
kwh at load factors of 100% 80%, 60%, 40% and 20% and plot the curve. (ans Load fctors and cost
per kwh; 100% 4.46p ,; 80% 5.65p; 40% 7.15p; 20% 11.5p)
Tis station supplies load to consumers. The cost of distribution system increases the fixed cost by
75% { this includes payment of dividend to stock holders} and the variable cost on full load at 100%
load factor( at the station) by 20% Work out the two part tariff per killowatt per month and per kwh
consumed.
When a) the load factor is 80% and (i) the diversity factor among the consumer is 2.3 and (ii) the
diversity factor among the consumer is 1.75
b) the load factor is 60% and (i) the diversity factor among the consumer is 2.3 and (ii) the diversity
factor among the consumer is 1.75
The losses in the distribution system may be taken as 10%
( Ans: (a) (i) Rs 9.75per kw per month and Rs 3.59 per kwh;(ii) Rs 12.8per kw per month and Rs
3.59 per kwh
(b) (i) Rs 9.75per kw per month and Rs 3.59 per kwh;(ii) Rs 12.8per kw per month and Rs 3.59 per
kwh