CHENNAI: Amid rising renewable energy capacity and carbon reduction commitments, the Tamil Nadu Power Distribution Corporation Limited (TNPDCL) is working on a 10-year power plan by analysing the demand gap between solar and non-solar hours.
According to the Central Electricity Authority’s (CEA) National Electricity Plan for resource adequacy for the period 2026-27 to 2035-36, power demand is higher during solar hours (7 am to 6 pm) between March and June. During non-solar hours, the demand drops by around 3,000-4,000 MW.
As per the CEA’s analysis of the demand gap between the solar and non-solar hours over the past two years (2024-25 and 2025-26 till January), Tamil Nadu’s average power demand stood at 20,871 MW, 20,399 MW and 21,183 MW in April, May and June of 2024-25 respectively. During non-solar hours in the corresponding period, the demand was lower at 20,116 MW, 19,688 MW and 20,209 MW.
A TNPDCL official said, “The gap between solar and non-solar hours is significant during the summer months, indicating strong daytime consumption supported by solar generation.
However, during the monsoon and winter months such as November and December, the gap narrowed or even reversed in some cases due to lower solar output and changing consumption patterns”.
“In 2025-26, the trend showed variation. While the summer months continued to record higher demand during the solar hours, a sharp rise was seen in July (22,859 MW), and again in October and November, when demand crossed 22,500 MW.
This increase is attributed to weaker rainfall and higher dependence on conventional power sources,” the official added. During the same period, the non-solar hour demand, however, remained relatively stable, ranging between 16,644 MW and 19,542 MW, indicating a flatter demand curve during night hours, the official further said.
On the power plan, an official said, “It assesses source-wise contributions to meet electricity demand and evaluates appropriate reserve margins.”