It’s often said that fans at live concerts give the band a jolt of electricity. Coldplay wants to literally harness that. The pop superstars have added kinetic dance floors and energy-storing stationary bikes to their latest world tour, encouraging fans to help power the show as they dance or spin. It’s part of a larger push to make the tour more environmentally friendly. The band — whose songs include the appropriately titled “Higher Power” — has pledged to be as sustainable and low-carbon as possible, hoping to cut their CO2 emissions by 50%.