Electricity, like clean water, is a resource that's often taken for granted. But last summer, when blackouts struck much of the northeastern US, Ontario and Rome, consumers on two continents were given a painful reminder of just how easily broken electricity supplies can be. The massive disorder stranded  commuters, stopped freezers, shut down businesses and refocused attention on where most of the planet's power comes from:oil-and-gas-fired generators and nuclear plants, These sources not only pollute the environment but also make many consumers feel unacceptable health risks. Companies are trying to offer an alternative, clean energy from renewable resources that's plentiful and portable. Lifton's Medis Technologies, as well as companies like Hydrogenics and Nanosys, is tapping into fuel cells and dolor panels to give people power whenever and wherever they want it, free from dependence on local grids . The search for alternative energy is nothing new, but the current trend of innovators is focusing on the goal of making clean and sustainable power a mainstream commodity. For example, the fuel cell, which produces electricity from the chemical reaction between oxygen and hydrogen, has been around for about 150 years, though its commercial development did not begin until the 1960s and then only as part of NASA spacecraft. Today this technology is coming down to Earth in places like Tokyo; in nine European cities, from Stockholm to Porto, each operating three hydrogen-fuel-cell buses; and in Iceland, which is trying to create the first fuel free hydrogen economy by 2030. When hydrogen and oxygen molecules combine, the reaction produces heat and water. Fuel cells use this reaction to generate electricity. With the cell phone and gadget market in mind, Medis has developed a fuel cell with cheap components that produces little heat and effortlessly reduces waste water without turning to energy consuming pumps. What is the passage mainly about?
The future of alternative energy How the fuel cells works People's search for alternative energy The damage done by the blackout last summer.