A. Standing charges that are independent of the output and (ii) running or operating charges that are proportional to the output.
B. Standing charges are proportional to the output and (ii) running or operating charges that are independent of the output
C. Standing charges that are proportional to the output and (ii) running or operating charges that are proportional to the output
D. Standing charges that are independent of the output and (ii) running or operating charges that are independent of the output.
Answer: A. Standing charges that are independent of the output and (ii) running or operating charges that are proportional to the output.
Explanation:
Tariff:
Definition:
- The amount of money frame by the supplier for the supply of electrical energy to various types of consumers is known as an electricity tariff. In other words, the tariff is the method of charging a consumer for consuming electric power. The tariff covers the total cost of producing and supplying electric energy plus a reasonable cost.
- The actual tariffs that customer pay depends on the consumption of electricity. The consumer bill varies according to their requirements. The industrial consumers pay more tariffs because they use more power for longer times than domestic consumers.
Costs and tariffs of electric supply mainly divided into 3 categories:
(1) Fixed cost:
It covers interest, depreciation, etc on secondary distribution cost.
Fixed costs or charges are also known as standing charges, which is independent of the output.
(2) Semi-fixed cost:
It depended on the maximum demand.
(3) Running cost or operating cost:
It depends on the units of energy consumed. So that running or operating charges are proportional to the output.
2. In the economic operation of a power system, the effect of increased penalty factor between a generating plant and system load current is to
A. decrease load on the generating plant
B. increase load on the plant
C. hold the plant load constant
D. increase power factor
Answer: A. decrease load on the generating plant
Explanation:
- Penalty factor in power system is a factor (greater than unity) by which the incremental cost of power production of plant must be multiplied to accommodate for the transmission losses.
- It is also defined as the ratio of power generated by the plant to the actual power demand of the load being met after transmission loss.
- The incremental production cost of all operating pants should be equal.
The effect of increased penalty factor between a generating plant and system load current is to decrease load on the generating plant.
3. The ratio of maximum demand on generating station to the installed capacity of plant gives:
A. load factor
B. operating factor
C. utilization factor
D. capacity factor
Answer: C. utilization factor
Explanation:
Utilization factor:
It is the ratio of maximum demand on the power station to the rated capacity of the power station.
Utilization factor = maximum demand / rated capacity
Load factor:
Utilization factor = maximum demand / rated capacity
Load factor:
The ratio of average load to the maximum demand during a given period is known as the load factor.
Load factor = average load/maximum demand
= Units generated in T hours/ (T × Maximum demand)
Plant capacity factor:
Load factor = average load/maximum demand
= Units generated in T hours/ (T × Maximum demand)
Plant capacity factor:
It is the ratio of actual energy produced to the maximum possible energy that could have been produced during a given period.
4. Which of the following is considered as an operational cost for a power system?
A. Fuel Cost
B. Insurance
C. Initial cost
D. Taxes and Interest
Answer: A. Fuel Cost
Explanation:
Running or operational cost of the power system:
- The concept of the running cost is quite simple. It solely depends on the number of units produced or generated.
- In a power generating plant, the main operational cost is the cost of fuel burnt per unit of electrical energy generation.
- The cost of lubricating oil, maintenance, repairs, and salaries of operating staff are also accounted for the operating cost of the plant.
- Since these charges are proportional to the number of units generated. For generating more units of electrical energy the required running expenditure is more and vice versa.
Important Point
- Initial cost or fixed cost is essentially capital costs and land.
- Fixed cost is the cost that is independent of max demand and units generated.
- The fixed cost is due to the annual cost of a central organization, interest on the capital cost of land, and salaries of higher officials.
5. What is the penalty factor of a plant if its incremental loss is 0.2?
A. 5
B. 0.8
C. 0.2
D. 1.25
Answer: D. 1.25
Explanation:
Penalty factor:
The penalty factor in the power system is a factor by which the incremental cost of power production of the plant must be multiplied to accommodate for the transmission losses.
It is also defined as the ratio of power generated by the plant to the actual power demand of the load being met after transmission loss.
The incremental production cost of all operating pants should be equal.
6. The ratio of sum of maximum demand of separate consumers to maximum demand of the station is given by __________.
A. Load factor
B. Utility factor
C. Diversity factor
D. Peak factor
Answer: C. Diversity factor
Explanation:
Diversity factor:
The ratio of the sum of individual maximum demands to the maximum demand on the power station is known as a diversity factor.
- A power station supplies load to various types of consumers whose maximum demands generally do not occur at the same time.
- Therefore, the maximum demand on the power station is always less than the sum of the individual maximum demands of the consumer.
- Hence diversity factor is always greater than 1.
- The knowledge of the diversity factor is vital in determining the capacity of the plant equipment.
- The greater the diversity factor, the lesser is the cost of generation of power.
- Because greater diversity factor means lesser maximum demand.
- Now, lower maximum demand means a lower capacity of the plant which reduces the cost of the plant.
7. The load factor is defined as the ratio of:
A. Maximum peak load to average load
B. Total load minimum load
C. Average load to the maximum load
D. Minimum load to total load
Answer: C. Average load to the maximum load
Explanation
Load factor:
The ratio of average load to the maximum demand during a given period is known as the load factor.
Load factor = average load/maximum demand
If the plant is in the operation for T hours
Important Points:
- The load factor may be daily load factor, monthly or annually if the period considered is a day or month, or year.
- The load factor is always less than 1 because the average load is smaller than the maximum demand.
- It plays a key role in determining the overall cost per unit generated.
- The higher the load factor of the power station, the lesser will be the cost per unit generated, is because a higher load factor means lesser maximum demand.
- The station capacity is so selected that it must meet the maximum demand.
- Now, lower maximum demand means a lower capacity of the plant which reduces the cost of the plant.