Rain Water Harvesting

Rain water harvesting system

          It is collection of rainwater from the surface which directly receives rainfall. It can be a paved area like a terrace or courtyard of a building, or an unpaved area like a lawn or open ground.A channel or gutters are required to transfer rainwater collected from rooftops to storage tanks or recharge pit.one or more down-pipes are connected to gutters to transfer rainwater from rooftops or terrace.

Storage of Direct use (Roof top rainwater harvesting)

         In this method rain water collected from the roof of the building is diverted to a storage tank. The storage tank has to be designed according to the water requirements, rainfall and catchment availability. Each drainpipe should have mesh filter at mouth and first flush device followed by filtration system before connecting to the storage tank. It is advisable that each tank should have excess water over flow system.Excess water could be diverted to recharge system. Water from storage tank can be used for secondary purposes such as washing and gardening etc. This is the most cost effective way of rainwater harvesting. The main advantage of collecting and using the rainwater during rainy season is not only to save water from conventional sources, but also to save energy incurred on transportation and distribution of water at the doorstep. This also conserve groundwater, if it is being extracted to meet the demand when rains are on.This method is less expensive and very effective and if implemented properly helps in augmenting the ground water level of the area.

Recharging ground water

        Ground water aquifers can be recharged by various kinds of structures to ensure percolation of rainwater in the ground instead of draining away from the surface. Commonly used recharging methods are:- 

                  a) Recharging of bore wells                

                  b) Recharging of dug wells.

                   c)  Recharge pits                                   

                   d) Recharge Trenches

                   e)  Percolation Tanks

                   ------) Multi stored buildings

Recharging of bore wells

         Rainwater collected from rooftop of the building is diverted through drainpipes to settlement or filtration tank. After settlement filtered water is diverted to bore wells to recharge deep aquifers. Abandoned bore wells can also be used for recharge.Optimum capacity of settlement tank/filtration tank can be designed on the basis of area of catchment, intensity of rainfall and recharge rate. While recharging, entry of floating matter and silt should be restricted because it may clog the recharge structure. First one or two shower should be flushed out through rain separator to avoid contamination. A schematic diagram of filtration tank recharging to bore well.

Solar energy in Schools

It is always said that “old habits die hard”, which means we tend to practice what we are preached. When we teach students in schools about solar power ,its effects for the future by the time they come to  implementation age it tends to become a habit of using this renewable energy into every project they take up.

Taking up the project of installing the solar power plant in schools, makes them understand that renewable energy is must for future to survive, they will in turn educate their parents to gradually shift towards renewable energy usage which reduces price burden and enables the continuous power supply .This will also encourage the entrepreneurship idea in a student for future resulting in at least few percentage of students to install solar power plants , which is very much needed in the current and future scenario

Our country India, experiences 300 days of sunlight, Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year. Solar energy is the technology used to harness the sun's energy and make it useable. The two major types of solar energy that make it to Earth are heat and light. Today, the technology produces less than one tenth of one percent of global energy demand. Solar energy is lauded as an inexhaustible fuel source that is pollution and often noise free.

The technology is also versatile. For example, solar cells generate energy for far-out places like satellites in Earth orbit and cabins deep in the Rocky Mountains as easily as they can power downtown buildings and futuristic cars. Japan, Germany, and the United States are major markets for solar cells. With tax incentives, solar electricity can often pay for itself in five to ten years.

Soon with the growing population we may face energy shortages hence the shift to solar energy is very important. In India, the solar market is undergoing changes from the incentive driven market to parity driven market. But this change is creating problem to policy makers and creating delays in policies. When a solar plant is installed, it’s average working period is 25 years and the break even period is around 13 years after which it starts giving profits , sometime break even period also depends on the plant size.

Installation of solar power in school acts  as a major step in reducing Co2 emissions because, in commercial buildings school is one of the constituent and source for major solar emissions. This will be an initiative from school to shift to renewable energy consumption and in the first place students will start learning . There are also various subsidies in relation with solar power, one of it being :-

 The solar energy corporation of India(SECI) was providing a capital subsidy for 100MW every year. Due to all the above reasons, we can expect new solar PV capacity of 750 MW in 2014.

Now, basically solar power can be generated both off-grid and on-grid power plants. But the off- grid has higher advantage .

Why off-grid roof top system:

• ·         Have access to power continuously all the time.
• ·        Not having any scheduled or unscheduled power cuts.
• ·        No dependency on diesel
• ·        The quality of this power is superior to the regular grid power.
• ·        Investment against increasing fuel and grid charges.
• ·        maintenance cost

Salient features of off-grid roof top system:

· Low and optimum maintenance cost.

· Stable supply of power increases the overall efficiency of electronic components.