On any given day, India’s trains carry more than 25 million passengers and nearly three million tons of freight. Most of these trains are powered by overhead electric lines or diesel generators that drive electric motors.
Between the locomotives and the stations, Indian railways consume an average of 4 GW of power, nearly two percent of the country’s total electric generating capacity.
Two of its largest rail operators, Indian Railways (IR) and the Delhi Metro Rail Corporation (DMRC), are constantly looking for ways to reduce fuel costs. At the same time, the nation recognizes the need to reduce greenhouse gas emissions.
They’re accomplishing both through a combination of energy efficient technology and photovoltaic panels on railway stations. Engineers are even experimenting with solar panels on the trains themselves.
Energy Efficiency
For the past eight years, DMRC has been upgrading its cars and facilities. LED lighting and skylights illuminate the stations with minimal power, while sophisticated temperature control systems and more efficient HVAC equipment reduce the energy needed for heating and cooling.
Aging rail cars are being replaced by coaches made of lightweight steel and the addition of regenerative braking helps capture energy that would otherwise dissipate as heat.
Rooftop PV on Train Stations
DMRC is adding 50 MW of rooftop photovoltaics to its train stations, which should generate about 20 percent of its electric needs.
With a goal to be powered entirely by renewable energy, the company plans to enter a power purchase agreement that will allow it to buy clean electricity from utility-scale PV farms at a reduced rate. So far they’ve installed about 2 MW of PV, which will prevent 1700 metric tons of CO2 from being pumped into the atmosphere every year.
Indian Railways currently has 10 MW of rooftop PV on its stations, which it plans to double in the near future. But the rail has a loftier five-year goal, hoping to install over 1 GW of photovoltaics using available land near the railways.
Solar Trains
India’s trains operate primarily above ground with much of its traffic running during daytime hours, so it seems logical that someone finally thought about putting PV panels on the trains themselves.
Studies suggest that adding solar power to a train can reduce its diesel consumption by 90,000 liters per year, cutting annual CO2 emissions by 200 tons.
Indian Railways is conducting a pilot study with one coach outfitted with a 2 kW array of PV panels. Early results indicate $1800 in annual fuel savings, just from the one car. As a bonus, when the train is parked it can export solar-generated electricity to the grid in a net-metering agreement.
Additional feasibility experiments are being conducted during monsoon season, so the results represent a worst-case scenario analysis.
In addition to measuring solar irradiance and panel output, the researchers are also conducting vibration analyses to determine the long-term stress on the panels.
Planning a trip to India? Maybe you’ll enjoy a ride on a solar train!