ME-604-C Renewable Energy Technology - May 2023 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aHow do you measure Solar Radiation?
   How to answer

   • Define solar radiation components - beam, diffuse, global
   • List measuring instruments - pyranometer, pyrheliometer, sunshine recorder
   • Explain working principle of each instrument
2. 7 Marks
   bExplain in detail, the solar radiation on tilted surfaces.
   How to answer

   • Define tilted surface geometry - tilt, azimuth, incidence angle
   • Explain beam, diffuse and reflected components on tilted plane
   • Give expression for total radiation on tilted surface
   • Discuss effect of orientation and tilt
3. 7 Marks
   aHow solar collectors are classified? What are the main applications of a drier?
   How to answer

   • Classify solar collectors - flat plate, concentrating, evacuated tube
   • Distinguish non-concentrating vs concentrating types
   • List main applications of solar drier - agriculture, food, timber
4. 7 Marks
   bCalculate the angle made by the beam radiation with the normal to a flat collector on Dec 1, at 9:00 A.M. solar time for a location at $28^{\circ} 35'N$. The collector is tilted at an angle of latitude plus $10^{\circ}$, with the horizontal and is pointing due south.
   How to answer

   • Calculate declination for Dec 1 (n=335) and hour angle for 9 AM
   • Determine tilt $\beta$ = latitude + $10^{\circ}$ and surface azimuth for due south
   • Apply $\cos\theta$ incidence angle formula
   • Compute $\theta$ value in degrees
5. 7 Marks
   aHow many types of Semiconductors or Solar cells are used to fabricate PV cells and modules?
   How to answer

   • List PV semiconductor generations - Si mono, poly, thin film, III-V
   • Mention CdTe, CIGS, perovskite, organic cells
   • State which are used for modules commercially
6. 7 Marks
   bDiscuss the step-by-step procedure to execute P and O algorithm for tracking the maximum power from the sun.
   How to answer

   • Define MPPT and Perturb and Observe principle
   • Give flowchart steps - measure V, I, P, perturb, observe dP
   • Explain convergence to maximum power point with conditions
7. 7 Marks
   aDerive the expression for Power developed due to wind.
   How to answer

   • Start from kinetic energy of wind mass $KE = (1/2)mv^2$
   • Express mass flow rate $\dot{m} = \rho A V$
   • Derive $P = (1/2)\rho A V^3$ and Betz limit concept
8. 7 Marks
   bWhat are some limitations of wind energy? What barriers are in place that make wind energy prohibitive?
   How to answer

   • List limitations - intermittency, low density, noise, land requirement
   • Discuss cost, grid integration and storage barriers
   • Explain why wind becomes prohibitive in some sites
9. 7 Marks
   aA tidal power plant of the simple single basin type has a basin area of $30\times 10^6\, \text{m}^2$. The tide has a range of 12 m. The turbine, however, stops operating when the head on it falls below 3 m. Calculate the energy generated in 1 filling (or emptying) process in kWh if the turbine generator efficiency is 0.73.
   How to answer

   • Use available head range from 12 m to 3 m for single basin
   • Apply energy formula $E = (1/2)\rho g A (R^2 - r^2)\eta$
   • Substitute $A=30\times10^6$, $R=12$, $r=3$, $\eta=0.73$
   • Convert J to kWh
10. 7 Marks
    bWhat is an Aero foil? Explain its types.
    How to answer

    • Define aerofoil as shaped blade cross-section
    • Explain lift vs drag principle
    • List types - symmetric, cambered, flat plate
11. 7 Marks
    aWhat is Biomass? How it is useful?
    How to answer

    • Define biomass and its sources
    • Explain conversion routes - combustion, gasification, biogas
    • State uses - heat, power, fuel
12. 7 Marks
    bDescribe the classification of fuel cell. With a neat sketch explain the working of fuel cell.
    How to answer

    • Classify fuel cells - AFC, PEMFC, PAFC, MCFC, SOFC
    • Draw neat sketch showing anode, cathode, electrolyte
    • Explain working with H2/O2 reactions and applications
13. 7 Marks
    aDifferentiate between Micro, Mini and Small hydro system.
    How to answer

    • Define micro, mini and small hydro by capacity range
    • Compare head, power output and application
    • Tabulate differences
14. 7 Marks
    bExplain the principle of Ocean thermal energy conversion.
    How to answer

    • State OTEC principle based on ocean temperature gradient
    • Explain open, closed and hybrid cycles
    • Mention warm surface and cold deep water working
15. 5 Marks
    aDefine the terms:

    1. i)Altitude angle
    2. ii)Incident angle
    How to answer

    • Define altitude angle as sun's angular height above horizon
    • Define incident angle as angle between beam and surface normal
    • Give significance/formula relevance
16. 5 Marks
    bShow that a wavelength of $\lambda = 1\, \mu m$ solar radiation corresponds to an energy of 1.24 eV. Give all assumptions made.
    How to answer

    • Use photon energy $E = hc/\lambda$
    • Substitute $h$, $c$, $\lambda = 1\,\mu m$ and convert J to eV
    • Show $E \approx 1.24\, eV$ and state assumptions
17. 4 Marks
    cSea waves are irregular in amplitude. How significant wave height is defined?
    How to answer

    • Explain irregular nature of sea waves
    • Define significant wave height as mean of highest one-third waves
    • Mention its use in wave energy estimation