1. Solve any five

(a) State the various direct applications of solar energy.

(b) Describe the potential of renewable energy sources in India.

(c) State the site selection criteria for locating wind mills.

(d) Define solar constant, air mass, solar altitude angle, angle of incidence.

(e) State atleast five sites/places available in India for harnessing rising geothermal energy.

(f) Describe working of Fixed dome type biogas plant.

2. (a) Describe construction and working of wind energy conversion system with neat sketch.

(b) Describe working of solar pumping system with neat sketch.

(c) Describe working of single basin tidal power plant.

3. (a) If the angle of declination on a particular day was +18.25$^\circ$C, which is the date assuming leap year? Calculate the day length on May 02$^{nd}$ on a surface sloping southward at an angle of 40$^\circ$C at a place of 19$^\circ$07' N latitude and 72$^\circ$51' longitude,

(b) Which factors affect the rate of production of biogas? State their ideal values/range for maximum biogas production?

(c) State the advantages and disadvantages of geothermal energy.

4. (a) State and explain the design consideration in wind turbine designs.

(b) Describe working of wave energy conversion system with neat sketch.

(c) State various parameters which affect performance of solar collectors. State limitations of flat plate collectors.

5. (a) Following observation were recorded from a test on Biogas system:

C.V. of methane: $28.5MJ/m^3$;

Burner efficiency: 60%;

Number of cows: 8;

Retention period: 20days;

Temperature of fermentation: $30^\circ$;

Dry matter collected per cow per day; 2Kg;

Density of dry matter in the fluid in the digester: $50Kg/m^3$;

Biogas yield: $02m^3$ per Kg of dry input;

Methane proportion in the biogas: 0.7. Determine the volume of digester and power available from biogas digester.

(b) Describe working of Claude cycle OTEC system with neat sketch.

(c) Describe working of Central tower receiver using Heliostat mirror with neat sketch.

6. (a) Calculate the rotor radius of multi-blade wind machine operating at a design speed of 25 kmph. The machine operates a water pump having a capacity of 5.1$m^3/hr$ and a lift of 9m. The following data is given:

Density of water = $996Kg/m^3$; efficiency of water pump = 0.6; efficiency of transmission from rotor to pump = 0.9; $C_p=0.31;\lambda=0.75;$ density of air is 1.2$Kg/m^3$.

(b) State the classification of fuel cells in brief and describe working of molten carbonate fuel cell with neat sketch.

(c) Describe working of low temperature binary fluid system with neat sketch.

7. Write short note on (any five)

(a) Energy audit

(b) Solar heating and cooling of buildings.

(c) Prospects of geothermal energy in context to India.

(d) Which wind data are taken into consideration and site selection of wind mills?

(e) Factors affecting biogas production.

(f) Strategy for meeting the and future energy requirements in India.

8. (a) What is Betz coefficient? Show that the ideal maximum theoretical efficiency is 59% for a horizontal axis windmill.

(b) Describe construction and working thermosyphon solar water heating system.

(c) What are liquid dominated hydrothermal resources? How these can be utilised in high temperature wet steam system?

9. (a) Determine the average value of solar radiation on horizontal surface for June 21, at latitude of 10$^\circ$N, if persons a and b are given as equal to 0.30 and 0.51 respectively and ratio $\dfrac nN$ = 0.55.

(b) Describe construction and working of floating dome type biogas plant with the help of neat sketch.

(c) Derive an equation for average tidal power generation per unit area of basin in terms of tidal range.

10. (a) Describe working of Darrieus type machines with help of neat sketch and its characteristics.

(b) Explain wave energy conversion devices?

(c) Describe the photo voltaic-solar cells and its applications.

11. (a) Wind at 1 bar and 20$^\circ$C has a velocity of 12m/s calculate:

(i) Total power density in wind stream

(ii) maximum power density

(iii) A reasonable obtainable power density

(iv) Total power produced if a rotor diameter is 60m and it runs at 50 rpm.

(v) The torque and axial stress produced at maximum efficiency.

(b) Describe working of Closed Cycle OTEC system with the help of neat sketch.

(c) Explain energy consumption as a measure of Nation's development.

12. (a) The following data given for a family biogas digester suitable for the output of 8 cows.

Given: Calorific value of methane: $28MJ/m^3$; Burner efficiency: 70%; Retention period: 20days; Temperature of fermentation: $30^\circ C$; Dry matter (cow dung) collected per cow per day: 2Kg; Density of dry matter in fluid(slurry) in the digester: $50kg/m^3$; Biogas yield: $0.2m^3$ per kg of dry input; Methane proportion in the biogas: 0.7

Calculate (i) The volume of biogas digester (ii) The power available from the digester.

(b) Explain the term 'slope' and surface azimuth angle of a surface facing the sun and bring out how sunset hour angle is affected by the slope

(c) Explain vapour dominated system belongs to geothermal energy

13. Solve any five

(a) State physics of solar photovoltaics.

(b) Strategy for meeting the future energy requirements in India.

(c) Site selection for windmill.

(d) Importance of energy audit.

(e) Environmental effects in the utilisation of Geothermal energy.

(f) Fuel properties of biogas.

14. (a) Derive an expression for maximum output fraction from wind power.

(b) Describe working of solar pumping system with neat sketch.

(c) Describe limitation of scope of tidal power plant.

15. (a) Calculate the local solar time and declination at a location latitude $23^\circ15'N$, longitude $77^\circ30'E$ at 12:30 IST on June 19, 2010. Equation of time correction is given from standard table for chart is 1'01''.

(b) Explain with sketches applications of biogas.

(c) Write a note on prospects of geothermal energy in India.

16. (a) Write a note on horizontal axis type wind turbine with the help of neat sketch.

(b) Discuss the working of single basin type tidal power plant.

(c) Discuss the working of flat plate collectors using air as a working fluid with the help of a neat sketch.

17. (a) Calculate the following parameters of a biogas system:

(i) The volume of biogas digester

(ii) The power available from biodigester

Given: Calorific value of methane: $28MJ/m^3$, Burner Efficiency: 70%, Number of cows: 8, Retention period: 20 days, Temperature of Fermentation: $30^\circ$, Dry matter (cow dung) collected per cow per day: 2Kg, Density of dry matter in fluid (slurry) in the digester: $50kg/m^3$, Biogas Yield: $0.2m^3$ per kg of dry input, Methane proportion in the biogas: 0.7

(b) Explain the concept of the total energy system in India.

(c) Explain basic sun-earth angles in details.

18. (a) Wind at 1 bar in 20$^\circ C$ has a velocity of 12m/s

Calculate (i) Total power density in wind stream.

(ii) Maximum power density

(iii) Reasonable obtainable power density

(iv) Total power produced if rotor diameter is 60 m and it runs at 50rpm.

(v) The torque and axial thrust produced at maximum efficiency.

(b) Discuss the analysis of aerodynamic forces acting on windmill blades.

(c) Discuss the prospects of Renewable energy sources in India.