Tata Motors has delivered hydrogen fuel cell-powered buses to Indian Oil, marking a step towards scaling up the technology. The buses use hydrogen as an energy source, which combines with oxygen to generate electricity. The electricity is stored in a battery and used to propel the wheels, making the buses zero-emission vehicles. In addition to the fuel cell technology, the buses also feature hydrogen storage, safety systems, telematics, and an intelligent transport system. The cost of these buses compared to diesel fuel buses will play a role in determining their future.