A coal-fired thermal power station and a nuclear power station have the following data:

                                            Coal         Nuclear

Capital cost ($/KW)                        700         800

Annual Interest and depreciation     10%         10%

Running cost per unit ($ / kWh)        0.341         0.153

Annual load factor                         50%             60%

On the basis of 1kW output on an annual basis

I) Calculate the annual capital cost of the coal-fired thermal power station

ii) Calculate the annual capital cost of the Nuclear power station

iii) Calculate the energy generated per annual for the Nuclear power station

iv) Calculate the energy generated per annual for the Coal power station

v) Calculate the cost of the energy generated per annum for the Coal power station

Q4.B) An overhead 3- phase transmission line has a conductor of section 90 mm² and an effective diameter of 1cm and is placed at the vertices of an equilateral triangle of side 1 metre. The line is 20 km long and delivers a load of 10MW at 33kV and a power factor of 0.8 lagging. Neglect capacitance of the line and assumes that at a temperature of 20 ^O C. the resistance of copper of 1mm² is 1 58 Ω per meter when the section is 1mm²

i)Determine the total resistance per phase of the transmission line.

ii) Determine the approximate total inductive reactance per phase of the transmission line

iii) Determine the sending end voltage, Vs of the transmission line

iv) Determine the percentage regulation of the transmission line.

v) Determine the per-unit transmission efficiency of the transmission line.

Q4.C) A supply system has the following tariff in force, GH₵ 100 .00 per kVA of maximum demand plus 5 pesewas per unit. A factory has a maximum demand of 2000 kVA when operating at a power factor of 0.7 lagging and a load factor of 85%. A power factor improvement equipment is installed to give a power factor of 0.95. The cost of the equipment is GH₵ 45.00 per kVAR and the rate of interest and depreciation is 10%.

i)Calculate the maximum demand of the factory at 0.95 power factor lagging.

ii) Determine the net annual savings in the electricity charge at a power factor of 0.95.

iii) Determine the most economical power factor at which the installation should be operated.

iv) Determine the net annual savings made at the most economical power factor.

Q4.D) Two conductors of a single-phase transmission line, each of 1cm diameter are arranged in a vertical plane with one conductor mounted 1 m above the other. A second identical line is mounted at the same height as the first and spaced horizontally 0.25m apart from it. The two upper and two lower conductors are connected in parallel.

i) Determine D_SA of the transmission line

ii) Determine D_SB of the transmission line

iii) Determine D_S of the transmission line

iv) Determine D_MAB of the transmission line

v) Determine the loop inductance per km of the transmission line