Tuesday, 27 November 2012

The Energy Guzzlers!

India has more than 500 million square meters of commercial built up area, which is expected to reach around 2000 million square meters by 2030 (assuming 5 to 6% growth rate), according to the USAID ECO III project report. Chennai alone has a lot of shopping malls, commercial complexes, Five-star hotels and theater complexes. According to TNEB sources the total energy requirement for Chennai is 2200MW out of which shopping areas / shopping malls like T.Nagar, Pondy bazaar etc. consume around 600MW and commercial buildings (office and software companies in the IT corridor) consume around 500MW of power. Here is a sample list:

Shopping complex - EA, Spencer’s, Ampa skywalk, Ispahani center, Fountain plaza, Ramee
Theater complex -Satyam cinemas Abirami complex, Citi center, Sangam cinemas
Commercial building -Olympia Tech Park, Thamarai Park, Asendas,
Hotels -Taj, Hilton, Hyatt, The Park, Le Royal meridian,

The energy (in Kilowatt-Hour) used per square meter per year in shopping centers in India varied between 103-532 kWh/Sq.m./year with an average of 252 kWh/Sq.m./year. Considering that, Chennai is currently estimated to have approximately 20,57,600 Sq.ft. of mall space, meaning that the average total power consumption of malls in Chennai is 4,81,71,617 kWh/Year.
Existing commercial one shift buildings in India consume around 149 units per square meter annually, therefore the total power consumption of a building per can be around 20lakh units a year. Similarly the average area of a 4 or 5 start hotel is projected to be around 19,136 Sq.mt, which consumes a enormous 48, 65, 711 units a year.

For our case study here I have considered the biggest shopping mall in south India, which is the Express Avenue (EA) at whites’ road in Chennai. EA is spread around 10 acres of land with a built area of 3.75Acres, which is equal to 1, 63, 350 sq. ft. This is 400 times the size of an average middleclass (single bedroom -400 Sq.ft) household in Chennai. 

The total retail space of the EA mall is 900,000 Sq.ft; therefore the consumption will be more than 2 crore units of electricity each year. These units of electricity are equivalent to lighting 18,000 household with an annual consumption of 1200 units each. 
 Source: The Hindu (Dated: December 2009)

If we just consider the 3.75 acres of rooftop area, it alone can carry a whopping 0.7 to 1 MWp of solar PV power capacity, which can generate around 12 to 16 lakh units a year and this can replace the grid electricity for around 1300  houses, with an average consumption of 100 units a month per household. But the energy generated is only a very small portion of the consumption which will be self consumed by the mall itself, but this can greatly bring down the load on TNEB grid.

3D Shadow simulation – based on avaiable data from Google

Upcoming malls in Chennai:
With reference to the Asicpac report on malls in Chennai, it is very clear that the local population is still shopping hungry and the demand still tops the supply. More than 62, 86,000 Sq.ft of malls (13 malls) are expected to be commissioned by end of 2013 at various parts of Chennai, mostly in the developing areas of the city. This will greatly bring down the shopping hunger demand, but at what cost? Do we have enough planning and power infrastructure for the further addition?

If all the above shopping malls, commercial building, star hotels and cinema complex are considered with solar PV rooftop installation, it can generate enough amount of electricity for the nearby neighborhood/houses or at least for the own building consumption and excess can be sent to the grid using the net metering concept.  

If the concept of energy efficiency and net metering/distributed generation is adopted by the above commercial complex / buildings, the nearby communities can greatly benefit and reduce the load on the unstable TNEB grid.  And this will also significantly reduce the power cuts in the urban/rural areas in Tamil nadu other than Chennai.

The recent Tamil Nadu solar state policy has implemented net metering for the very first time along with the GBI (Generation Based Incentives). As per the policy, commercial establishments, colleges, government buildings, residential schools, IT parks, industries, and buildings with a built-up area of 20,000sqm come under the Solar Purchase Obligation (SPO). They can meet this 6% SPO by generating their own power, purchasing solar power from the state electricity board or by purchasing power from private solar power producers. Recently TEDA has announced that all colleges in Tamil Nadu should have solar PV systems in their rooftops, you can find the information here - Must for all colleges by 2014

This policy can be a game changer for the rooftop segment as the GBI details below show. GBI can easily make the payback or return on investment faster, provided the GBI is implemented quickly along with existing subsidy. The question, however, is can TNEB recover from its big losses and implement SPO effectively?
Rooftop GBI
(projects commissioned before 31 Mar - 2014)

Year 1
Year 2
Year 3
Year 4
Year 5
Year 6
Rs. 2/kWh
Rs. 2/kWh
Rs. 1/kWh
Rs. 1/kWh
Rs. 0.5/kWh

- Giridaran Srinivasan 


  1. Nice article hope these projects bring relief to tamilnadu especially for those who are living in the rural .

  2. Good insight to the present and future energy consumption of Chennai. The proposal makes a lot of sense as well. Good going Giri.

  3. tats a great piece of info,hope ur blog wakes many more people regarding renewables

  4. Very well and informative content given about every day is a special day ,every minute is to live and cherish. Thanks for given this information here about this blog.
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