Barcelona's subway system is using regenerative braking to help power both its convoys but also recharge electric cars at street level. Sixteen subway stations in the Spanish city are equipped so that the energy from the regenerative braking system on the train can also help power chargers for electric cars. Making better use of energy has become a key pillar of reducing rising global temperatures. Countries at last year's United Nations climate talks and the members of the Group of 20 agreed to double energy efficiency by 2030.
