The noble Lord is as knowledgeable about the original hydrogen fuel cell installation in London as I am, because it was under my control that it was put in. Of course, the truth is that an installation for three vehicles out of a fleet of 8,000 would proportionately be enormously expensive, but it was there for a reason: to experiment with hydrogen fuel cells. The result has been generational change in fuel cells for vehicles. The Government believe that, in appropriate circumstances, hydrogen is one way of getting zero emissions. We do not get technical progress without experimentation; we expect the cost to decline. That, together with electricity, will be the way of producing zero-emission buses and bus fares at reasonable prices.