This is how you can help reduce evening peak-hour power demand

CHENNAI: Tamil Nadu can reduce pressure on the power grid by encouraging households, offices and electric vehicle users to shift some of their electricity use away from peak hours, a new study has found.

Such measures could provide 207-253 MW of flexibility during the evening peak hours between 6 pm and 10 pm, said a study by the Centre for Study of Science, Technology, and Policy (CSTEP), adding that another 60-73 MW could be made available during the morning peak.

However, this does not mean the State will permanently save 253 MW of electricity. Instead, consumers can change the time at which they use electricity. For example, geysers and washing machines can be used during periods when demand is lower, while offices can pre-cool buildings before the evening hours when the load peaks.

The study estimates that these measures could shift or save around 156 million units (MU) of electricity a year and provide an estimated benefit of Rs 313 crore annually by reducing power purchase costs, transmission losses, and the need for new capacity.

The study comes at a time when Tamil Nadu's power demand has been rising steadily. Peak demand increased from 16,386 MW in FY20 to 20,830 MW in FY25. It stood at 20,211 MW in FY26 and is projected to reach 27,090 MW by FY30 and 35,263 MW by FY35.

Renewable energy accounts for nearly 58% of Tamil Nadu's installed capacity. As of June, the State has an installed capacity of about 47,978 MW, including 27,648 MW of renewable energy.

The study said this creates a problem because solar power is available mainly during the day, while electricity demand rises sharply in the evening. Shifting some consumption to daytime could, therefore, help the State make better use of renewable power.

The study covered 2.5 lakh households, 1.7 lakh commercial buildings, 10,000 EVs and 500 public EV charging stations.

Among the various consumers, households could provide 61-75 MW of flexibility during the evening peak by managing air-conditioners, geysers, washing machines, and water pumps. Commercial buildings could provide the biggest share, at 126-154 MW, mainly by managing air-conditioning. The study estimates annual benefits of around Rs 102-125 crore from these measures.

Managed charging of electric vehicles could provide another 20-24 MW, with an estimated annual benefit of Rs 18-22 crore.

The study has recommended starting with pilot projects, including automatic controls for geysers and air-conditioners, delayed charging of EVs, and shifting electricity use to periods of high solar generation.

It has proposed expanding such programmes over the next three to five years and eventually treating demand flexibility as another resource for meeting Tamil Nadu's power requirements.

What is demand flexibility?

Demand flexibility means shifting or adjusting electricity use to reduce pressure on the power grid during peak-demand hours

Examples:

Use geysers during the day when solar power is available
Pre-cool offices before the evening peak and reduce AC use during peak hours
Shift washing machines usage to non-peak hours
Charge vehicles during the afternoon or late night instead of the evening peak