Energy Audit

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Ah well, thank you for reminding me that I’m still ignoring fifth grade environmental education. First thoughts, right? Considering this and factoring your laziness, we thought that congratulating you on being the cheapest subscribers of electricity in Mumbai seemed apt. What if we ask you how much of a part you play in the wastage of this electricity? What do we generally tend to do if faced with this query? Blame that fourthie in the wing who has an assortment of electronics? Or it’s surely that wingie of yours who uses his laptop as a desktop 24×7, the guy to be blamed. Or perhaps the mess people, it must be them leaving the mess and lounge lights on all night. An incessant barrage of questions have been raised on the apparent wastage of electricity in the institute, especially in hostels. Concerns about the veracity of these claims led to the fruition of the following analysis.

Area wise consumption of energy

In this article, we delve into the distribution of the consumption of electricity in the different parts of our institute. Which hostel consumes the most? Is there a department which dominates over the consumption from academic area? As we looked into this, most results are as one would expect but with some eye-opening numbers in support.
Out of a total of 29,226,976 units consumed by our institute in 2015 (excluding staff residences), around 69% was accounted for by the academic area itself, which isn’t really surprising with all the departments and secret(?) facilities working on large scale projects. The residential area, all our hostels, guesthouse, etc., accounted for around 29% and the rest of the institute takes care of the remaining 2%.

If we look at the distribution across departments, the Electrical department consumes a whopping 23% of the total while other departments consume around 6-7% each. The high consumption may be justified given the department’s three buildings – two high demand national facilities in NCPRE and the Nanoelectronics building and that most of their research labs are open for almost 24×7 to cater to demands of a strength of around 1300 students.
Let us have a look at something we can better relate to. How do the hostels compare? If we look at the new hostels against the old hostels, the per capita consumption of H12-H14 and H15 does come out to be more as compared to H2-H11. This can be explained by the relatively new infrastructure and the fact that they completely rely on electric heaters instead of solar heaters as in the older hostels. But a major factor could also be that Hostels 12 to 14 have single rooms against the double rooms in other hostels. A caveat though is that without individual room consumption data, these explanations don’t have numbers backing them up. The other anomaly is H1. But the data is from the time when a large part of H1 was being reconstructed and the spike can thus be attributed to the reconstruction work. The solar and electric heaters have also recently been separated which has resulted in people relying solely on the electric ones.


Another interesting fact we observed was the variation in consumption over the year from the Gymkhana grounds. With Mood Indigo and Techfest scheduled near the year end, a huge spike (~32% of the total consumption) in December can be attributed to these fests which contribute 5 to 6 times the consumption in an average month.

Consumption: Insti vs Mumbai

Outside main-gate, the per capita consumption across the city is close to 1200 units. While the cost per unit varies from supplier to supplier, taking Rs. 6 as the average cost per unit, the average Mumbaikar pays anywhere between Rs. 7000 to Rs. 9000 per year for electricity. Students, on the other hand, consume about 940 units a year in hostels alone, they are charged only Rs. 5000 for two semesters as electricity cost.


Solar Consumption

Solar energy in the insitiute has not been put to much use. Apart from the solar water heaters on the hostels, the institute generates around 670 kW of solar power, with an aim of improving it to 1MW. However, this is very less compared to the amount of electricity consumed in the institute.



A seemingly obvious fact was that the electricity consumption in hostels is a tiny portion of the total and if our goal is to reduce energy consumption per capita significantly then measures must be taken at the institutional level and not solely focused on hostels. One such measure was a circular sent out to all professors describing how to curb the excessive use of air-conditioners in labs and offices. The hypothesis that hostel areas are major energy sinks therefore doesn’t hold up. While we should definitely promote energy conservation on an individual level and inculcate a culture of economical use, citing those as primary sources of waste is incorrect.


We would like to thank Prof. Rangan Banerjee from the Energy department for helping us out with the data. He is currently leading a team of students on an extensive analysis of the electricity consumption in our institute. A more detailed report shall be released soon.