Renewable Energy Technologies (RET) important questionsMost repeated in SPPU papers
These 13 questions appeared in more than one SPPU Renewable Energy Technologies paper we have: 8 papers, from Feb 2023 to Nov 2025. The most-asked come first. Each one links to the papers it was asked in.
Repeated questions
Endsem questions (13)
- 4×asked
A propeller type wind turbine has the following data: Speed of the free wind at a height of 10 m = 12 m/s Air density = 1.226, = 0.14 , Height of tower = 100 m, Diameter of rotor = 80 m, Wind velocity at the turbine reduces by 20 %, Generator efficiency = 85% Determine. i) Total Power available in wind Power extracted by the turbine. ii) Electrical power generated Axial thrust on the turbine. iii) Maximum axial thrust on the turbine.
- 4×asked
- 3×asked
A biomass gasifier is used to run a compression ignition engine. The engine operates in the dual fuel mode with 75 % diesel replacement. The biomass feeding rate for the gasifier is 170 kg/hr. Calculate the power produced by the engine, if the engine efficiency is 28 % and calorific value of biomass is 15500 k.J/kg. Consider efficiency of the gasifier is 0.70.
- 3×asked
Design a standalone PV system for the load specified in the table. Load Number Power Rating (Watt) Usage Hr/day T.V 1 100 2 Refrigerator 2 50 8 Computer 3 18 5 Find: i) Energy supplied (Wh) by the battery to inverter input considering inverter efficiency = 85 %. ii) Considering Depth of Discharge (DOD) of 50 %, calculate the required charge capacity of battery (24V). iii) Considering two days of autonomy, calculate battery charge capacity. iv) Calculate no. of batteries needed for 24 V system voltage if the available battery configuration is 12 V and 100 Ah. v) Calculate the number of panels of 60 W p for the above case considering 6 sunshine hours of 1000 W/m 2 -day. Assume battery efficiency = 80 %, Assume controller circuit efficiency = 100%. 2
- 3×asked
- 2×asked
A residential house has a power requirement of 400 W for 4 hours every night. It is proposed to meet the requirement by using a PV array, a battery storage system and an inverter. The whole system is over designed so that it can meet one extra night’s requirement even if there has been no sunshine during the day. Calculate number of PV modules and batteries required. Given : i) Solar radiation is available for an average of six hours daily and average hourly global radiation flux incident on the array is 650 W/m 2 . ii) Battery rating = 12 V; 120 Ah. Depth of discharge = 0.7 Charging and discharging efficiency = 0.9. iii) Inverter efficiency at full load =0.85. 2
- 2×asked
- 2×asked
- 2×asked
- 2×asked
- 2×asked
- 2×asked
- 2×asked
Questions count as repeated when their wording matches closely across papers. Numericals that depend on a figure are left out, since the figure changes from paper to paper.