1. Pusa Hydrogel
  2. Eco-Cooker
  3. Micro-grid power generation
  4. Rajiv Gandhi Net-metering se Bill kum karlo Yojana
  5. Earth overshoot day

Pusa Hydrogel

Topic in news: Oct 2014, Hindu; Relevance: GS3- Science-Technology / conservation;

  • Who? Indian Agricultural Research institute, New Delhi
  • What? Pusa Hydrogel is a granular product. Made by cross-linking hydrophilic (water-loving) polymers.
  • Mix the dry powder with seeds + 10 times soil + necessary fertilizers. Then plow the farm, spread this mixture.

Ya but what’s the benefit?:

  • During irrigation, the Hydrogel will absorb and retain water just like a sponge. 350xtimes its dry weight.
  • During dry period, it’ll release the water for plants.
  • Thus, gel reduces water requirement for crops. Improves seed germination,.
  • Helps farmers in arid areas. Less money, diesel, electricity spent on irrigation.


Topic in news: Oct 2014, Hindu; Relevance: GS3-S&T in everyday life ;

  • Who? An Andhra corporation, a pvt.company and Mumbai based research institute. (names not important because they’re not high profile like ISRO, TERI etc.)
  • What? An ‘Eco Cooker’ that saves 70% energy than LPG.

But How?

Eco Cooker

Eco Cooker benefits

  • Modified gas regulatory: gas flow is controlled in such manner that temperature remains constant at 72 degree.
  • Modified burner design to spread the flame evenly.
  • Uses a sealed close circuit to trap steam and heat.


  • 30% of National Energy goes into cooking. Eco-cooker uses 70% less energy used than in LPG.
  • Ideal for canteen, hotel, hostels.
  • Can cook multiple items in one go-rice, dal, veggies etc.
  • Preserves food’s nutritional value, Improves food’s taste.

Micro-grid power generation

Topic in news: Oct 2014, Hindu; Relevance: GS3-infrastructure: Energy / conservation;

Discuss the important of Microgrid power generation to solve the electricity-shortage in rural India. 100 words.

Ans. A micro grid is made up of three components:

  1. Power generation system – usually a renewable source: solar panel, windmills.
  2. Energy storage facility
  3. Load Management system.

A single microgrid (2-3MW) can serve 5000 families.

  • These Micro grids are independent, self-sufficient and a practical solution to provide electricity to off-grid and inaccessible areas.
  • At present such families rely either on firewood or diesel- both harming environment. Micro grid electricity can benefit rural/tribal children in education and farmers in irrigation.
  • System already successful in USA, and American companies have shown interest to replicate the model in India.

Net metering to reduce lightbill

Topic in news: May 2014, Hindu; Relevance: GS3-Energy/ conversation

Q.Discuss the utility of Net-metering system to solve the electricity crisis in Urban area. 100 words

Ans. Under Net-metering system, Customer installs a solar or windpower plant on his premise, gets it grid-connected with the electricity distribution company (DISCOM)

Net Metering

  • Customer uses solar electricity for his own house, and transmit excess solar energy to DISCOM.
  • During monsoon, cloudy days or heavy usage, he can use the conventional electricity from the DISCOM (generated by thermal or nuke power plant).
  • The electricity bill will be calculated on the ‘net’ transfer between customer and DISCOM.
  • IF customer gave more (solar) energy to DISCOM, the (thermal) electricity he consumed=> DISCOM will have to pay the customer. And vice versa.
  • Hence it is called “Net” Metering”.
  • Benefits: less light bill, environment protection, fight climate change, solar panel can run for ~25 years.
  • Limitations: requires initial investment of ~1-3 lakh rupees to buy the solar panel. Takes ~3 years to recover investment.

Earth overshoot day

Topic in news: August 2014, Frontline; Relevance: GS3-Environment degradation

Mains-GS3: Q.Discuss the significance of Earth Overshoot day. 100 words

Unlike the World environment day (June 5), Earth overshoot day is not fixed permanently for every year.
For the given year, the Earth Overshoot day is observed on a day when:

  1. humans have consumed more than biosphere can replace
  2. humans created more waste than nature can absorb

2014: Earth Overshoot day observed on 19th August (8th month of the year)

  • Meaning, we’ve used up earth’s annual (12 month) supply of water, land and trees within 8 months.
  • We are generating waste, litter, CO2 at faster rater (8 months) than earth’s annual speed to absorb / biodegrade such waste.
  • It means, we are currently living on next year’s quota. So, next year’s overshoot day will occur even sooner than August 2015.
  • If corrective steps not done, then by 2030, we’ll need “Two earths” to meet our resource requirements and absorb our waste.

Side notes:

  1. Also called Ecological debt day.
  2. this day not decided by IPCC, UNEF etc., but an NGO called Global footprint Network.