With growing encroachment of the concrete jungle, the space for green in metros is shrinking. The only unutilized space available is the rooftop. The idea is to create a landscape of grass (actual grass on the floor, with layers of insulation that avoid seepage through the building), shrubs and creepers. An aver. corporate rooftop will have approx. 4000 sq ft. space available for such a garden. Now multiply that to the no. of buildings that corporate buildings occupy worldwide then we are talking about a green cover equivalent to hundreds of football stadiums put together.
Benefits a. The grass will help in converting CO2 and other emission gases into O2.
b. Due to the insulation on the rooftop, heat will be preserved inside the building during winters and vice versa heat absorption (sunrays) will be minimized during the summers. Both lead to lesser usage of the central air-conditioning.
We are talking about installation of turbines in pipes that carry water downwards. Having an over-head water tank is the only requirement for the success of this idea and which all sky-scrapers do have. For example, a single turbine installed strategically in our building will be enough to light up all the CFL bulbs in our terrace. Such high buildings offer further opportunity to install multiple turbines top down.
Waste Water Management
Instead of letting out waste water from buildings into the drainage, we can dig up pits to process this sewage and extract Bio-gas before being let out. The same gas can be used in our pantries for cooking. This is one of the oldest unconventional methods of extracting energy.
Benefits a. These are readily available technologies with minimal investments.
b. Very uncomplicated in terms of installation.
c. A big leap from being a 'Carbon Neutral' entity to becoming a 'Green Energy Producer'.