Important Questions and Answers: Economics of Power Plants

Conventional POWER PLANTS AND ECONOMICS OF POWER PLANTS`

1. List the non – conventional energy sources?

The various non-conventional energy sources are as follows:

·        Ocean thermal energy conversion

·        Tidal energy

·        Geothermal energy

·        Hydrogen energy

·        Fuel cells

·        Magneto-hydrodynamics generator

·        Thermionic converter

·        Thermo-electric power.

2. Write the advantages of non – conventional Energy sources? Advantages of non-conventional energy sources:

The leading advantages of non-conventional energy sources are:

1.     They do not pollute the atmosphere

2.     They are available in large quantities.

3.     They are well suited for decentralized use.

3. Write the characteristic’s of wind energy?

1.     Wind-power systems do not pollute the atmosphere.

2.     Fuel provision and transport are not required in wind-power systems.

3.     Wind energy is a renewable source of energy.

4.     Wind energy when produced on small scale is cheaper, but competitive with conventional power generating systems when produced on a large scale.

Wind energy entails following short comings/problems:

1.     It is fluctuating in nature.

2.     Due to its irregularity it needs storage devices.

3.     Wind power generating systems produce ample noise.

4.  What  are  the  advantages  and  limitation  of  Tidal  power  generation?

Advantages:

1.     Tidal power is completely independent of the precipitation (rain) and its uncertainty besides being inexhaustible.

2.     Large area of valuable land is not required.

3.     When a tidal power plant works in combination with thermal or hydro-electric system peak power demand can be effectively met with.

4.     Tidal power generation is free from pollution.

Limitations:

1.     Due to variation in tidal range the output is not uniform.

2.     Since the turbines have to work on a wide range of head variation (due to variable tidal range) the plant efficiency is affected.

3.     There is a fear of machinery being corroded due to corrosive sea water.

4.     It is difficult to carry out construction in sea.

5.     As compared to other sources of energy, the tidal power plant is costly.

6.      Sedimentation and silteration of basins are the problems associated with tidal power plants.

7.     The power transmission cost is high because the tidal power plants are located away from load centers.

5. Write the advantages of MHD systems?

1.     More reliable since there are no moving parts.

2.     In MHD system the efficiency can be about 50% (still higher expected) as compared to less than 40% for most efficient steam plants.

3.     Power produced is free of pollution.

4.     As soon as it is started it can reach the full power level.

5.     The size of plant is considerably smaller than conventional fossil fuel plants.

6.     Less overall operational cost.

7.     The capital cost of MHD plants is comparable to those of conventional steam plants.

8.     Better utilization of fuel.

9.     Suitable for peak power generation and emergency service.

6. Write the advantages of OTEC?

1.     Ocean is an infinite heat reservoir which receives solar incidence throughout the year.

2.     Energy is freely available

Write the disadvantages of OTEC?

1.     Efficiency is very low, about 2.5%, as compared to 30 - 40% efficiency for conventional power plants.

2.     Capital cost is very high

7. Define – Tidal power plant?

The tidal power plants are generally classified on the basis of the number of basins used for power generations. They are further subdivided as one-way or two-way system as per the cycle of operation for power generation.

8. Write the application of geothermal energy?

The following are the three main applications of the steam and hot water from the wet geothermal reservoirs:

1.     Generation of electric power.

2.     Space heating for buildings.

3.     Industrial process heat.

The major benefit of geothermal energy is its varied application and versatility.

9.  What  are  the  Advantages  and  disadvantages  of  Geothermal  Energy  over

other  Energy forms?

Advantages of geothermal process:

1.     Geothermal energy is cheaper.

2.     It is versatile in its use.

3.     It is the least polluting as compared to other conventional energy sources.

4.     It is amenable for multiple uses from a single resources

5.     Geothermal power plants have the highest annual load factors of 85 percent to 90 per cent compared to 45 per cent to 50 per cent for fossil fuel plants.

6.     It delivers greater amount of net energy from its system as compared to other alternative or conventional systems.

Disadvantages:

1.     Low overall power production efficiency (about 15% as compared to 35% to 40% for fossil fuel plants).

2.     Drilling operation is noisy.

3.     Large areas are needed for exploitation of geo-thermal energy.

4.            The withdrawal of large amounts of steam or water from a hydro-thermal reservoir may result in surface subsidence or settlement.

10.            Define demand factor?

·        Demand factor is defined as the ratio of maximum demand to connected load.

·        Connected load is the sum of ratings in kW of equipment installed in the consumer's premises.

·        Maximum demand is the maximum load, which a consumer uses at any time.

11.            Define load curve?

Load curve is a graphical representation between load in kW and time in hours. It. shows variati6n of load at the power station. The area under the load curve -represents the energy generated in a particular period.

12. Define load factor?

Load factor is defined as the ratio of average load to the peak load (or) maximum demand.

13. What includes fixed cost?

Fixed cost includes the following cost.

1.       Cost of land        

2.       Cost of building

3.       Cost of equipment        

4.       Cost of installati6n

5.       Interest      

6.       Depreciation cost

7.       Insurance   

8.       Management cost

14. What includes operating cost?

Operating cost includes the following cost.

1. Cost of fuel                                   2. Cost of operating labour,

3. Cost of maintenance labours and materials.

4. Cost of supplier like

Water for feeding boilers, for condenser and for general use.

Lubrication oil and, grease.

Water treatment chemicals.

15. What is the need of depreciation cost?

Depreciation cost is the amount to be set aside per year from the income of the plant to meet the depreciation caused by the age of service, wear and tear of the machinery and equipments. Depreciation amount collected every year helps in replacing and repairing the equipment.