Bengaluru Metro highlights technical feasibility challenges for Blue Line solar traction

Bengaluru: Bangalore Metro Rail Corporation Ltd (BMRCL) officials have flagged several technical and design challenges in adopting full solar traction for the upcoming Blue Line.

Responding to an Indian Institute of Science (IISc) study that proposed running the corridor entirely on solar power, BMRCL officials, addressing a seminar on the study, said Tuesday that solar traction is not part of the detailed project report (DPR) on which the Blue Line is being executed. “Of course, the study has brought up half information and it gives a chance for us to… think really in terms of how best we can implement it. But there are certain challenges that we have to address before we conclude it,” said Dodde Gowda, chief engineer (traction), BMRCL.

Namma Metro’s Blue Line corridor, once completed, will be 55km long and will stretch from Central Silk Board to Kempegowda International Airport in north Bengaluru. It will also serve the Outer Ring Road (ORR), which is home to a significant number of the city’s tech parks.

Gowda said rooftop solar capacity estimates would need to be reassessed against feasibility and installation best practices, citing prior experience where vendor assessments led to “drastic reductions” from initial expectations. He added that space constraints were another limiting factor for the stretch between KR Pura and Central Silk Board.

“Only in four stations do we have this additional space earmarked for the installation of solar instruments and equipment. For the remaining stations, the layout is already done; it’s at a very advanced stage and now equipment is being moved to these substations for installations because we are working on a very tight target,” Gowda explained.

He noted that BMRCL has already been implementing solar initiatives on other corridors, including Yellow Line and the Green Line extension along Kanakapura Road.

On financing, Gowda said solar traction was not included in DPR costs and would require alternative models such as public-private partnerships. He said private parties currently install and operate solar systems and are paid for generation, but scaling this for traction would require mobilising additional funds.

He also highlighted the need for a dedicated technical study on injecting solar power into the Metro’s 33kV network. Officials said that beyond solar panels, components such as cables, transformers, and switchgear would be required.