PhysicsMarichi · UPSC
Hydropower ki Physics: mgh se Megawatt aur Energy Security tak
Solar aur wind sasti ho rahi hain, phir bhi Himalaya mein bade hydro project kyun aa rahe hain?
Socho pehle… phir dekho jawab
Kyunki hydropower firm aur non-fossil hai — solar-wind ko balance kar sakta hai — aur storage dam baadh bhi moderate kar sakta hai. Physics seedhi hai: P = ηρgQH. Himalayan nadiyon mein tez dhalaan (H) aur zyada discharge (Q) dono milte hain.
Physics: potential energy (mgh) → penstock mein kinetic → turbine → generator (electromagnetic induction) → grid. P = ηρgQH; net head, penstock friction ki wajah se gross head se kam. Example: 1 m³/s aur 100 m head ≈ 1 MW (loss ignore karke). Pumped storage: surplus bijli se paani upar pump karo, peak demand par gira ke bijli banao — ek tarah ki 'paani ki battery'.
Types: run-of-the-river — nadi ke flow par, limited pondage; storage — bada reservoir, sookhe mausam ke liye paani aur flood moderation. Card: Subansiri Upper — 1,605 MW, NHPC, Menga ke paas, 237 m storage dam; stated objectives bijli aur flood moderation. Subansiri, discharge ke hisaab se Brahmaputra ki sabse badi tributary hai. Card ka analysis: 'run-of-the-river' label aur 237 m storage dam ka contradiction appraisal ko saaf karna chahiye — kitna paani rukega, releases kaise honge.
Governance hook: EIA Notification, 2006 (Environment (Protection) Act, 1986 ke tehat) — 50 MW ya usse zyada ke river valley hydro projects Category A, Centre ki sectoral Expert Appraisal Committee dekhti hai; EAC ki sifarish advisory hai, clearance Ministry deti hai. Himalayan risk: sabse oonchi seismic zone aur glacial lakes — isliye GLOF discharge aur dam-breach assessment ab appraisal ka hissa hai.
Prelims trap: run-of-the-river ka matlab 'zero storage' nahi, limited pondage hota hai; aur 'renewable' hone se har bada hydro project apne aap 'low-impact' nahi ho jaata. Analysis angle: firm clean power vs basin-level cumulative asar — ek-ek project nahi, poori nadi ka hisaab.
Ghar pe try karo
Physics-cum-policy skeleton 150 words mein banao: intro (P = ηρgQH; Himalaya mein H aur Q), fayde (firm, non-fossil, solar-wind balancing, flood moderation), risks (seismic zone, GLOF, downstream flow aur sediment), governance (EIA 2006 Category A, EAC advisory), conclusion (basin-wide planning).
Wow!
1 m³ paani har second 100 m se gire toh loss ignore karke ~1 MW — yaani 1,605 MW ke liye Subansiri jaisi badi nadi aur bada head, dono chahiye.
3 sawaal
- EIA Notification, 2006 ke tehat river valley hydroelectric project Category A mein kab aata hai?
Jawab dekho
50 MW ya zyada. 50 MW ya usse zyada ke hydro projects Category A hain, Centre ki EAC appraise karti hai.
- Pumped storage plant ke baare mein sahi kathan?
Jawab dekho
Surplus bijli se paani upar pump karke peak demand par gira ke bijli banata hai. Pumped storage bijli ko paani ki oonchai ke roop mein store karta hai.
- Trap: run-of-the-river project ke baare mein sahi kathan?
Jawab dekho
Yeh nadi ke flow par chalta hai, limited pondage ke saath. Run-of-the-river mein limited storage hota hai, zero nahi; storage dam mein bada reservoir.
NCERT se jodo: GS3 — Infrastructure (energy), Science & Technology, Environment (EIA); GS1 — physical geography (Himalayan drainage); NCERT Class 11 Physics — work, energy and power; Class 12 Physics — electromagnetic induction