After Sputnik shot into orbit in the 1950s, our future became populated by robot butlers and flying cars.
And today, as we face the specter of climate change and disappearing natural resources, our visions of the future include alternative energy solutions.
But what do we mean by the phrase "alternative energy?" Aside from crude oil, there's a wide array of viable options: Natural gas. Coal. Geothermal. The list goes on and on.
But in the midst of international tension and pollution, relying on a dwindling supply of fossil fuels is a futile exercise at best. New forms of alternative energy must be free from the limitations of the ones we're using now. The subtext here is sustainability -- the ability of alternative energy sources to sustain themselves.
So what kinds of alternative energy can we predict for the next century?
Here's a quick list:
Hydrogen Fuel Cells. Since well before Toyota introduced the Prius gas-electric hybrid, we've been speculating as to how we'd power automobiles with alternative energy. But the popularity of the Prius has driven business and industry to pursue better ways to fuel cars. One of the best answers is hydrogen gas, since it can be drawn from conventional crude oil sources and (like gasoline), "alternative energy" sources (like biodiesel). The hydrogen drawn from these sources powers fuel cells to power a vehicle's motor. The only emission is water.
Biofuels. If you've ever been camping, you've used biofuels: Campfires burn biomass (dried or decomposed organic material) to create heat and light. In the process known as prolysis, organic products are burned to create liquid fuels. These fuels can be used to power an internal combustion engine or a hydrogen fuel cell vehicle. However, burning biomass produces carbon, which contributes to global warming.
Solar Power. As far as sustainability goes, solar power wins the gold medal; the sun isn't scheduled to expend its supply of hydrogen gas for another four and a half billion years. Solar power uses photovoltaic cells to turn sunlight into usable energy. And though business and industry have generally been slow to convert power systems to solar, there are several notable exceptions: One Southern California utility announced plans to spend $900 billion on photovoltaic power generation in the Mojave desert. Home Depot, the home improvement retail store, has also begun offering solar installation service to its clients.
Wind Power. Windmills aren't just for quaint old farms anymore. Though wind power has been used as far back as the 1800s (when it helped to irrigate crops), it's only come into its own relatively recently. Now, wind farms speckle the landscape throughout the American southwest.
Wave Energy. Off the coast of Portugal sits the world's firs commercial "wave farm" -- an installation intended to generate power from the motion of ocean waves. The key to wave power is the Pelamis Wave Energy Converter, the device that makes the whole process possible. The Pelamis is designed to survive even the harshest waves, since it only absorbs a portion of the energy of each wave.
