Background
In Mumbai, the urban local body, Municipal Corporation of Greater Mumbai (MCGM), supplies water through its pipeline network from the treatment plant to the underground tank of each residential building. The stored water in the underground tank is then pumped to the overhead tanks situated on the terrace of every building through a pumping system. As the electricity consumption for water pumping activity is directly proportional to the height of the building and number of occupants (volume of water requirement), the growth in the number of high-rise buildings in the city are directly contributing to the increase in the consumption of electricity for end-use pumping application. The ever increasing urbanization characterized by a sprawl of apartment complexes, the end-use application has become as important as other domestic applications such as lighting and water heating. Therefore, IIEC’s Mumbai Energy Alliance has implemented the pilot project on end-use pumping with funding from the Overbrook Foundation.

Project Activities

The project implementation activities covered – 1. Situational analysis of Mumbai residential buildings 2. Market characterization 3. Walkthrough audits for about 40 residential Co-operative Housing Societies (CHS)
4. Investment grade energy audits for 12 residential CHS
5. Roundtable discussions with leading pump manufacturers, energy auditors, licensed plumbers and electricians. 6. Formation of working group consisting of industry experts for selection of the best suitable pump sets for the societies. 7. Installation of new energy efficient pump sets with best plumbing practices
8. Evaluation Monitoring & Verification of savings with real-time meters

Results of the project from 3 societies
The new pump sets are fully operational from March 24, 2010 and the key points from the actual field measurements of three pumping systems and savings are:
1. The Society 1 (Krishna – Godavari) pumping system: Efficiency is increased to 45% from earlier 30% with an investment of INR 50,000. Annual electricity savings are approx 1619 kWh with pay back of 5 years. 2. The Society 2 (Aditya-Anirudh) pumping system: Efficiency is increased to 52% from earlier 14% with an investment of INR 20,000. Annual electricity savings are approx 1528 kWh with pay back of 2 years.
3. The Society 3 (Shiv Ganga) pumping system: Efficiency is increased to 37% from earlier 22% with an investment of INR 30,000. Annual electricity savings are approx 1277 kWh with pay back of 3 years.

IIEC acknowledge the support provided by Ansons Electro Mechanical Works, CRI Pumps India Pvt Ltd, Crompton Greaves Ltd and Kirloskar Brothers Limited for supplying pump set of different technologies (submersible, vertical inline, multistage Bore well submersible etc.) to test their applicability for the project demonstration. IIEC also acknowledges the support provided by Reliance Infrastructure in implementation of this project.

Learnings and scale-up potential

• Manufacturers must bring down the cost of energy efficient pump-sets with rated efficiency between 55%-60%
  • Actual efficiency improvement is 1.5 – 2 times but the initial cost is four times higher (includes installation cost)
• Pump Manufacturers need to appreciate that
  • The potential for retrofit of low efficiency pump-sets in residential buildings is only 13% to 30%)
  •  Only installation of star label pumps sets would not increase overall pumping system efficiency (Pump should be selected to operating duty points of individual pumping system) 
  • The pumping system efficiency with small size pumps can be improved cost effectively upto 55% with better technology

• Specific consumption (m3/kWh) and hours of operation of the pump set for entire year must be captured during monitoring & evaluation of energy savings
• Efficiency of pumping systems in high-rise building is good
• Energy efficiency improvement potential is highest in the centralized pumping systems and parallel operation of pumping system
• Convincing residential societies to invest in the project requires effort
• Project if implemented in about 100,000 residential buildings (5-10 storey buildings) would save
• Annual electricity savings of 208 MkWh with an investment potential of approx. 91 million USD (INR around 400 crores)
• 1.8 million tCO2  emission reduction over 10 year period

Any one interested in visiting the societies can find the details below:

Residential Building 1: Krishna – Godavari   
Suchidham Housing Complex, Senior Citizen Welfare Association, Near Dindoshi Bus Depot, Malad (E), Mumbai

Residential Building 2: Aditya – Anirudh    
Chincholi Bandar Road, Near Inorbit Mall, Malad (W)

Residential Building 3: Shiv Ganga   
Soni Complex, Chincholi Bandar Road, Near Inorbit Mall, Malad (W)

Residential Building 4: Tapovan
Krishnadham, Rani sati marg extension, Pathanwadi, Malad (E)

Note: The pumping system in residential building 4 is commissioned in the last week of June and the post implementation results are not yet captured.

For further details on the project, please write to us at mea@iiec.org.