Sun shines bright on Chennai Central

Solar panels that supply electricity from morning till evening100kW solar panels installed above the main building of the station

Malavika Prasad

Chennai: Despite the South Central Railways’ (SCR) initiative to make what is now called ‘Chennai Central’ railway station fully solar powered, the station does not have the ability to store excess solar energy yet, experts say.

Chennai Central is another feat in SCR’s move towards ‘Energy Neutral’ railway stations after the Nandyal-Yerraguntla section in the Guntakal Division was declared as the first solar section, as per a press release of the Ministry of Railways early last year.

Central Electricals Limited have manufactured and installed the Inverters throughout the station and are responsible for periodical maintenance checks once every two weeks

According to L. Jagadeesan, Senior Section Engineer, Electrical and Power Division, at the station, the project was commissioned in 2017 with 100kW solar panels on a trial basis. “In December 2018 additional 100kW solar panels were added to the station. In it’s pilot stage currently, the solar capacity is at 1.5MW,” he says.

Jagadeesan says that solar energy can be produced only from morning till evening until sunset. For nighttime use the station relies on traditional coal fuelled electricity supplied from Tamil Nadu Generation and Distribution Corporation Ltd. (TANGEDCO), the main distribution licensee in the city.

He explained, “We first draw power from the grid to enable the solar panels. The panels generate DC voltage, which the inverters installed throughout the stations convert into AC voltage. These digital inverters display the amount of daily and monthly electricity produced and consumed at the station.” 

Solar panels installed above Platform’s 2A, 3, 4 and 5

An inspection of the station showed that there are 100kW panels installed above the roof of the main building, 500kW solar panels above platforms 2A, 3-7 and 900kW solar panels above the adjoining Egmore railway station.

Inventor installed between Platform 2A and 3            

M.M. Kumar, Junior Engineer, said that the station is producing excess energy during the day however there is no mechanism at the moment to store this excess energy for use after sunset. The excess is exported back to the state grid run by TANGEDCO.

This begs the following question. Can a busy metropolitan railway station run on solar energy long-term?

Aravind Kannan, marketing head at ‘Solarify’, a Bangalore based solar power company (recently acquired by SunEdison) says, “Conventionally solar energy can be conserved in Lithium-ion batteries. Using batteries for an area of this scale like Chennai Central is expensive.”  Therefore, exporting the excess energy back to the state grid is the best option.

The electricity produced at the station runs on a net metering system. Kannan explains this with an example. “If in a monthly billing cycle, 1000 units of solar power can be generated at the station, wherein 500 units are consumed during the day (live usage), then the remaining 500 units are exported back to the grid. If the station pulls additional 1000 units from the grid for consumption at night or on an overcast day, it will pay for the net 500 units of additional electricity required for consumption to the Distribution Licensee.” According to him, the grids act like a virtual battery.

Critics of solar energy harp on the cost of maintenance as the reason for its slow growth in the Indian energy market. But Varsha Ram Balapa, who has worked in the solar energy sector for 5 years and is currently pursuing her masters in Industrial Ecology & Solar Energy at TU Delft and Leiden University, disagrees.

“Maintenance of solar panels is not expensive, it just has to be done regularly. The biggest costs associated with rooftop solar are related to the components. Post set up and grid connection any decent maintenance will keep it running for 20 years,” Balapa explains.

Kannan alluded to political reasons why there isn’t a separate storage mechanism for excess solar power at Chennai Central. “If there are more non-conventional options of energy generation like solar then it will decrease the demand for traditional energy affecting the business of big players like TANGEDCO,” he said.

These reasons aside, the Centre has appreciated the move towards energy neutral stations like Chennai Central. Whether this move will pay off or not remains to be known.