On 28 July 2026, the government reported that over 48 lakh households have benefited under PM Surya Ghar: Muft Bijli Yojana — India's flagship rooftop-solar scheme — with 18.71 lakh systems (6.7 GW) installed in 2025-26 alone. For an NDA aspirant, this is a strong science-and-energy topic: it explains how solar cells work (the photovoltaic effect), net metering, and India's renewable-energy push — all high-yield.
The news in one frame
The essentials:
- What: 48 lakh+ households benefited under PM Surya Ghar: Muft Bijli Yojana (since February 2024).
- Scale: 18.71 lakh rooftop systems (6.7 GW) installed in 2025-26.
- How: central subsidy + low-interest loans for rooftop solar (RTS), applied for on a national portal.
- Aim: free/cheap electricity for households and a big push to India's solar capacity.
How a solar cell works — the physics
Start with the science — the heart of the topic. A solar photovoltaic (PV) cell converts sunlight directly into electricity:
- It is made of a semiconductor — usually silicon — formed into a p-n junction (like a diode).
- When sunlight (photons) strikes the cell, it knocks electrons loose from atoms; the built-in electric field at the junction pushes them in one direction, producing an electric current. This is the photovoltaic effect.
- Cells produce DC (direct current); an inverter converts it to AC for household use and the grid.
- Many cells make a module/panel, and many panels make an array.
A key distinction: solar PV converts light → electricity, while solar thermal uses the sun's heat (e.g., solar water heaters, concentrated solar power). This physics is exactly what the NDA physics notes build.
Net metering and rooftop solar
The examinable mechanism:
- Rooftop Solar (RTS) means panels installed on a home/building's roof, connected to the DISCOM (distribution company) grid.
- Net metering lets a household export surplus solar power to the grid and get credit against the electricity it draws at other times — so the bill reflects the "net" consumption. This is why the scheme can deliver "muft bijli" (free electricity) up to a limit.
- Benefits: lower bills, no land needed (uses idle roofs), reduced transmission losses (power is used where it is generated), and cleaner energy.
- Challenges: upfront cost (addressed by subsidy/loans), intermittency (needs storage or grid balancing), and space/orientation.
These themes recur in the NDA daily current affairs.
India's solar and renewable push
Place the scheme in national policy — a reliable discriminator:
- PM Surya Ghar: Muft Bijli Yojana (Feb 2024) — subsidised rooftop solar for 1 crore households.
- PM-KUSUM — solar pumps and grid-connected solar for farmers (the government is promoting convergence of the two schemes).
- National Solar Mission — one of the eight missions under the NAPCC.
- Targets: 500 GW of non-fossil capacity by 2030 (India crossed 50% non-fossil installed capacity in 2025, five years early).
- International Solar Alliance (ISA) — co-founded by India and France, headquartered at Gurugram, to promote solar globally.
The revision hook: solar PV cell = silicon semiconductor p-n junction converting light → electricity (photovoltaic effect); PV (light) vs solar thermal (heat); DC → inverter → AC; net metering credits surplus exported to the grid; PM Surya Ghar (Feb 2024) subsidises rooftop solar for 1 crore homes; PM-KUSUM = farmers' solar; ISA (HQ Gurugram); 500 GW non-fossil by 2030.
Why solar matters for India
Round out with the strategic picture:
- Abundant resource: India receives strong sunshine across most of the country for ~300 days a year — ideal for solar.
- Energy security: solar cuts dependence on imported coal and oil, and reduces the import bill.
- Climate: solar is central to India's net-zero-by-2070 and NDC commitments.
- Decentralised power: rooftop solar empowers households and farmers to become "prosumers" (producer + consumer).
Why it matters
For the SSB and the bigger picture:
- Affordable power: cheaper electricity directly improves household welfare.
- Self-reliance: domestic solar manufacturing (under PLI) builds Aatmanirbhar clean-energy capacity.
- Climate action: every rooftop adds to India's clean-energy transition.
Exam relevance in one paragraph
For NDA General Science, retain: a solar photovoltaic (PV) cell is made of a semiconductor (usually silicon) forming a p-n junction and converts sunlight directly into electricity via the photovoltaic effect, producing DC that an inverter turns into AC — distinct from solar thermal, which uses the sun's heat; rooftop solar connects to the DISCOM grid with net metering, which credits surplus power exported to the grid; PM Surya Ghar: Muft Bijli Yojana (launched February 2024) subsidises rooftop solar for one crore households, while PM-KUSUM serves farmers; India targets 500 GW of non-fossil capacity by 2030 (it crossed 50% non-fossil installed capacity in 2025), and co-founded the International Solar Alliance (HQ Gurugram). For the SSB, it exemplifies clean, decentralised energy for every home.
🎯 Practice MCQs
Q1. A solar PV cell converts sunlight into: (a) electricity directly (b) heat only (c) sound (d) fuel → (a) — electricity (the photovoltaic effect).
Q2. Solar cells are usually made of which material? (a) silicon (b) copper (c) gold (d) rubber → (a) — silicon (a semiconductor).
Q3. The effect by which light generates electricity in a cell is the: (a) photovoltaic effect (b) greenhouse effect (c) Doppler effect (d) tidal effect → (a) — the photovoltaic effect.
Q4. Solar PV differs from solar thermal because PV uses: (a) light to make electricity (b) heat to make electricity only (c) wind (d) water → (a) — light (thermal uses heat).
Q5. A solar panel produces ___ current, converted by an inverter. (a) direct (DC) (b) alternating (AC) (c) no (d) static → (a) — DC, converted to AC.
Q6. "Net metering" allows a household to: (a) export surplus solar power to the grid for credit (b) pay double (c) store coal (d) avoid all bills forever → (a) — get credit for exported power.
Q7. PM Surya Ghar: Muft Bijli Yojana was launched in: (a) February 2024 (b) 2014 (c) 2030 (d) 2005 → (a) — February 2024.
Q8. PM Surya Ghar targets rooftop solar for: (a) 1 crore households (b) 100 households (c) only factories (d) only offices → (a) — one crore households.
Q9. The scheme for solar pumps for farmers is: (a) PM-KUSUM (b) PM-KISAN (c) FAME (d) Ujjwala → (a) — PM-KUSUM.
Q10. India's non-fossil capacity target for 2030 is: (a) 500 GW (b) 50 GW (c) 5 GW (d) 5,000 GW → (a) — 500 GW.
Q11. The International Solar Alliance is headquartered at: (a) Gurugram, India (b) Paris (c) Geneva (d) New York → (a) — Gurugram (India).
Q12. Rooftop solar reduces transmission losses because power is: (a) used where it is generated (b) sent far away (c) stored in coal (d) exported abroad → (a) — consumed on site.
Q13. A p-n junction in a solar cell is formed by: (a) doping a semiconductor (b) melting iron (c) burning coal (d) freezing water → (a) — doping (as in diodes/transistors).
Q14. A household that both produces and consumes power is a: (a) prosumer (b) consumer only (c) producer only (d) trader → (a) — a "prosumer."
Q15. The National Solar Mission is part of the: (a) NAPCC (National Action Plan on Climate Change) (b) WTO (c) NITI Aayog (d) IPCC → (a) — the NAPCC (one of its eight missions).
Q16. The device converting a solar panel's DC into usable AC is the: (a) inverter (b) transformer only (c) capacitor (d) resistor → (a) — an inverter.
Q17. PM Surya Ghar comes under which ministry? (a) New & Renewable Energy (b) Power only (c) Agriculture (d) Finance → (a) — the Ministry of New & Renewable Energy.
Q18. A key limitation of solar power that needs storage/grid balancing is its: (a) intermittency (available only by day) (b) high pollution (c) fuel cost (d) noise → (a) — intermittency.
Q19. Rooftop solar systems are connected to the grid through the local: (a) DISCOM (distribution company) (b) post office (c) bank (d) panchayat → (a) — the electricity distribution company.
📋 How this gets asked (PYQ pattern)
Renewable energy is a high-frequency NDA science set. The reliable framings are the photovoltaic effect (light→electricity), PV vs solar thermal, net metering, and scheme-to-beneficiary matching (Surya Ghar-households, KUSUM-farmers). A common trap says a PV cell works on the sun's heat (it works on light) or swaps the two schemes. The fresh 2026 hook is PM Surya Ghar's 48 lakh households — ideal for "which effect / which scheme / which target" items. We reference the pattern, not any exact past question.
Preparing for the NDA? Solar energy, renewables and India's targets are high-yield science topics and good SSB talking points on clean-energy self-reliance. Follow our daily NDA current affairs and train with serving-officer faculty in the upcoming Cavalier courses in Delhi.
✍️ Written by Col D.N. Sharma — Science & general-studies faculty at The Cavalier. Reviewed by the Cavalier Faculty Desk. The Cavalier, founded by ex-Army officers, has trained NDA/CDS/SSB aspirants since 2001 (Facebook · YouTube).
Source: PIB / Ministry of New & Renewable Energy, 28 July 2026. Facts cross-verified with independent sources.