Bengaluru 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 addressed a seminar on the study on Tuesday. They stated that solar traction is not part of the detailed project report (DPR) on which the Blue Line is being executed.
Half Information and Need for Further Thought
Dodde Gowda, chief engineer (traction) at BMRCL, acknowledged the study's value but noted that it presented only partial information. He said, “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.”
Blue Line Corridor Overview
Namma Metro’s Blue Line corridor, once completed, will be 55 km long, stretching 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.
Rooftop Solar Capacity and Space Constraints
Gowda explained that rooftop solar capacity estimates would need to be reassessed against feasibility and installation best practices. He cited prior experience where vendor assessments led to “drastic reductions” from initial expectations. Space constraints are another limiting factor, especially for the stretch between KR Pura and Central Silk Board. He noted that only four stations have additional space earmarked for installing solar instruments and equipment. For the remaining stations, the layout is already finalized and equipment is being moved to substations for installation due to tight targets.
Existing Solar Initiatives
Gowda highlighted that BMRCL has already been implementing solar initiatives on other corridors, including the Yellow Line and the Green Line extension along Kanakapura Road.
Financing Challenges
On financing, Gowda stated that solar traction was not included in DPR costs and would require alternative models such as public-private partnerships (PPP). Currently, private parties install and operate solar systems and are paid for generation. However, scaling this for traction would require mobilizing additional funds.
Need for Technical Study
He also emphasized the need for a dedicated technical study on injecting solar power into the Metro’s 33 kV network. Officials noted that beyond solar panels, components such as cables, transformers, and switchgear would be required.
