REDEFINING GREEN!

Green energy (a.k.a renewable or sustainable energy) comes from natural sources like sunlight, wind, water, and geothermal. Because green energy can be produced with little or no pollution, it’s far more environment-friendly than other types of energy. It doesn’t contribute to climate change or global warming like traditional energy sources. Moreover, unlike fossil fuels such as coal and oil, green energy sources are renewable, meaning they replenish naturally and are in continuous supply. Biomass, Landfill gases, gases released in mines, etc are often categorized as green energy sources as well. This is primarily because they can be easily used to generate electricity which not only reduces pollution but also avoids the release of greenhouse gases which significantly contribute to global warming.

India's installed renewable power generation capacity touched 2,000 GW in 2016. Although "Green" encompasses several power generation technologies, it is mostly dominated by Hydro (52%), Wind (32%) and Solar (11%). Hydro power being the oldest technology of power generation, it continues to dominate this energy segment.

Share of hydro, solar and wind energy (Source: IRENA - Renewable Capacity Statistics 2017).

After several failed and abandoned installations on biomass based power generation/gasification plants, India has few successfully running power plants now. It has been taken a step further by Waste to Energy (WTE) technology which not only efficiently generates power from biomass/Municipal Solid Waste (MSW) but also cleans the hazardous gases produced in the process before releasing the same in atmosphere.

Geothermal, landfill gases, etc are still a technology to be explored and exploited profitably.

The technology surpassing them in the race of "Green" energy is Waste Heat Recovery System (WHRS).

What is Waste Heat Recovery System?

Waste Heat Recovery System is basically Recycle of Energy. Every Process industry consumes energy in some or the other form. A major share of this energy is lost to the environment which not only degrades the overall energy efficiency of the plant but also increases the cost of operations. For instance, Process industries such as Cement, Steel, Glass, etc consume around 80-90% of energy in form of heat for their several processes. This energy requirement is often met by fossil fuels and around 20-30% of this heat is lost to the environment in form of waste exhaust gases. Further, prior to releasing the "waste" gases, the statutory requirement mandates the organisation to "treat" the waste before releasing the same in the environment. The treatment is often a costly affair and consumes a lot of water even in States often hit by drought. Moreover, this process consumes additional energy thereby further bringing down the already low plant energy efficiency.

WHRS or Recycle of energy not only recovers this waste heat but also increases the overall plant energy efficiency and lowers the operation cost. The WHRS may offer any or all of the following solutions depending upon the quantum of waste heat available or requirement of the Process plant:

1.      Power

2.      Process Steam/Heating

3.      Chiller/Cooling

4.      Waste water recycling, etc.

Like all other types of Green energy, WHRS helps in reducing pollution, lowers greenhouse gases emission, lowers carbon footprint and has almost zero cost of operation as the 'fuel' is available free of cost and for entire life of the plant.

Hence, WHRS will make the industry (and hence economy) leaner, cleaner and greener.