"The first underground sub-station will be set up near the TNEB headquarters itself. Land has been identified for the same. The ceiling of these sub-stations will be very strong, like those built by the army. No water seepage or power leak will happen," said C P Singh, chairman of the TNEB. This is being touted as the first underground sub-station in the country.
A substation is a part of an electrical generation, transmission, and distribution system, where voltage changed from high to low or the reverse. From the generating point, electricity is flowed to the consumer through these sub-stations.
There are over 1,300 sub-stations across the state and in Chennai alone there are over 50. But due to lack of land in the city, the TNEB has not been able to construct more sub-stations that are required to improve power supply and reduce transmission losses.
Nearly 10 acres of land is needed for a 230 KV substation, five acres for a 110 KV and two acres for a 33 KV sub-station. But for indoor or gas-insulated sub-stations (GIS), only two acres, one acre and 3/4 acre will be required respectively.
"Land in the city is very costly and we are not able to find any. But it is very essential to have more sub-stations to prevent low voltage and transmission loss. The underground ones will be GIS and will occupy lesser space," said a senior TNEB official.
"Beneath a big park we can have two 33 KV sub-stations. Though there will be no electricity leakage, we can still have them under the corners of the park where people won't venture and can put a warning board too," the official said.
If the load of a particular area is 16 Megavolt Amperes (MVA), a 33 KV sub-station has to be set up. If the load is 50 MVA, a 110 KV sub-station is required. A 230 KV sub-station is required for a load between 50 MVA and 300 MVA; and for load over 300 MVA, a 400 KV sub-station is needed.
"We plan to have 33 KV sub-stations under the parks. We need the cooperation of the Chennai Corporation to implement this project. We will be approaching them soon for permission," said the TNEB official.
Source - Times of India