How a metro system generates its own electricity

Nowhere is more energy consumed than in our world’s cities, where already over half the global population live. And that figure is rising. But those places that consume the most energy also have the potential to achieve the biggest savings – CO2 emissions from road traffic being a prime example.

The Indian capital New Delhi – a megacity of 16 million inhabitants – launched a metro service in 2002, which today spans a network covering 190 kilometres with 142 stations. On the one hand, this is more climate-friendly than the cars and motorcycles so typical of Asian countries; and yet the metro uses enormous amounts of electricity – equivalent to 100,000 Indian households per month. And this electricity also has to be generated.

Environmentally friendly electricity for environmentally friendly local transport

New Delhi is now trying to achieve two goals in one go, by generating ‘green electricity’ and at the same time providing its metro network with a reliable power supply. This is because the city’s mass transport system is currently plagued by regular power outages as a result of a chronically overloaded and dilapidated grid. So the city has come up with a solar power solution, with electricity generated right where it’s consumed.

The metro operator Delhi Metro Rail Corporation (DMRC) turned to GIZ for support with setting up the first solar power systems. On behalf of the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB), GIZ promotes the commercial use of solar energy. GIZ advised DMRC on financing and planning the solar systems and helped find suitable buildings on which to install the solar panels.

An initial pilot phase – the planning basis for future phases – saw the installation of solar panels on the roofs of three metro stations. In the meantime, solar panels have now been installed on the roofs of five more DMRC buildings, delivering an output capacity of three megawatts. That is enough power to supply on average 4,000 Indian households with electricity. But the potential is enormous: there are already plans to install solar systems with an output of 50 megawatts by 2017. This would enable the New Delhi metro system to generate a share of its own electricity. In addition, DMRC is working with an energy provider to develop a solar power plant in Rajasthan, with an output capacity of 500 megawatts. With the output from the power plant and roof systems combined, DMRC would then be able meet its entire electricity requirements using solar energy.

This is a small step for India in achieving its climate targets: the emerging economy aims to increase its share of renewable energies in total electricity consumption fivefold to 25 per cent in the years ahead, most of it through the use of solar power. By 2030, India also aims to reduce CO2 emissions by at least 30 per cent – despite the country’s growing energy demand. GIZ has helped India save over 163 million tonnes of greenhouse gases since 2000. That is greater than the total annual greenhouse gas emissions from road traffic in Germany.