--- title: "Conventional vs non-conventional sources with schematic" subject: "Power System Analysis I" chapter: 1 key: "semester_4/power_system_analysis_i:conventional-vs-nonconventional-sources-schematic" source: https://www.bctengineer.com/q/semester_4/power_system_analysis_i/conventional-vs-nonconventional-sources-schematic site: BCT Engineering --- # Conventional vs non-conventional sources with schematic Power System Analysis I · Chapter 1: General Background - Asked in: 2082 Kartik (new course), 2+4 marks - Video: [Energy Resources - Conventional and Non-Conventional](https://www.youtube.com/watch?v=Zgp86PVXXuQ) — Amit Sengupta - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_4/power_system_analysis_i/conventional-vs-nonconventional-sources-schematic - Whole chapter: https://www.bctengineer.com/md/semester_4/power_system_analysis_i/chapter-1 ## Question What are differences between conventional and non-conventional sources of energy? Draw a schematic diagram of one of the power generating stations with non-conventional sources. ## Short answer Conventional sources (coal, gas, nuclear) are finite, polluting, with high fuel cost, and large centralised plants. Non-conventional sources (solar, wind, micro-hydro) are renewable, low-polluting, often intermitent, and can be small/decentralised. A grid-connected solar PV plant uses a PV array, DC combiner/MPPT, inverter to AC, step-up transformer, and feeds the 11 kV grid. ## Answer #### Differences **Conventional sources** (coal, oil, gas, nuclear, large hydro in many texts) are long-established, mostly finite, and used in large central plants. **Non-conventional sources** (solar, wind, small/micro hydro, biomass, geothermal, tidal) are newer, mostly renewable and often small and decentralised. | Basis | Conventional | Non-conventional | |---|---|---| | Nature | Mostly exhaustible | Renewable, inexhaustible | | Pollution | High (CO₂, ash, waste) | Low or nil | | Running cost | High (fuel) | Low (free fuel) | | Output | Steady, dispatchable | Often intermittent | | Scale | Large, centralised | Small to medium, decentralised | | Technology | Mature | Developing | #### Schematic: grid-connected solar PV power plant ```text Sunlight | [PV array] --DC--> [DC combiner/ (modules) MPPT charge] | [Inverter DC->AC] | 400 V AC [Step-up Tx 0.4/11 kV] | [CB / meter] | 11 kV grid (optional: battery bank on DC side) ``` **Working:** 1. PV modules convert sunlight directly into DC electricity (photovoltaic effect). 2. Strings of modules are combined, and the MPPT controller keeps them at the maximum power point. 3. The inverter converts DC to grid-synchronised 3-phase AC. 4. A transformer steps up the voltage and the power is fed into the grid through protection and metering. An off-grid plant uses a battery bank to store energy for the night. Example: the 25 MW grid-connected solar plant at Devighat, Nuwakot, feeds Nepal's national grid in this way. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. How do non-conventional sources differ from conventional ones? A. Mostly exhaustible and highly polluting B. Large central plants with mature technology C. Always dispatchable D. Mostly renewable, low pollution, often small and decentralised Answer: D. Solar, wind, micro-hydro, biomass etc. are renewable and small; conventional ones are finite and central. (Key point: Nature of sources) 2. Which is true about output of non-conventional sources? A. Often intermittent B. Always steady and dispatchable C. Constant at night for solar D. Independent of weather Answer: A. Solar and wind vary with the resource, unlike conventional steady output. (Key point: Output) 3. What is the order of equipment in a grid-connected solar plant? A. PV array - transformer - inverter - MPPT B. PV array - MPPT/combiner - inverter - step-up transformer - grid C. Inverter - PV array - grid D. PV array - generator - turbine - grid Answer: B. DC from PV is combined, converted by the inverter to AC, then stepped up. (Key point: PV plant chain) 4. What do the MPPT and inverter do? A. MPPT converts DC to AC; the inverter steps up voltage B. Both store energy C. MPPT keeps modules at maximum power point; the inverter converts DC to grid-synchronised AC D. Both rectify AC to DC Answer: C. MPPT optimises the DC output and the inverter produces AC synchronised to the grid. (Key point: Inverter and MPPT) ## Related in Power System Analysis I - [Conventional sources and features of a station](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Aconventional-sources-features) — Power System Analysis I, chapter 1 - [Conventional vs renewable energy for generation](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Aconventional-vs-renewable-generation) — Power System Analysis I, chapter 1, asked 2× - [Types of renewable energy sources](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Arenewable-energy-types) — Power System Analysis I, chapter 1 - [Hydro and thermal power sources](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Ahydro-thermal-sources) — Power System Analysis I, chapter 1 - [Two sources via 0 - j5 Ω: power flow](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Atwo-sources-0-j5) — Power System Analysis I, chapter 3 - [Renewable sources and least suitable for Nepal](https://www.bctengineer.com/question.md?key=semester_4%2Fpower_system_analysis_i%3Arenewable-sources-least-suitable-nepal) — Power System Analysis I, chapter 1 ## Related in other subjects - [Conventional, non-conventional sources and biomass](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aenergy-sources-biomass) — Power Plant Design, chapter 1 - [Conventional and non-conventional sources](https://www.bctengineer.com/question.md?key=semester_7%2Fenergy_environment_and_society%3Aconventional-nonconventional-sources) — Energy Environment and Society, chapter 2 - [Replacing fossil fuel with non-conventional energy](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aenergy-sources-replace-fossil) — Power Plant Design, chapter 1 - [Energy sources and solar power generation](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aenergy-sources-solar-power) — Power Plant Design, chapter 1