Back in the 1831, a British inventor named Michael Faraday figured out that if he passed a magnet back and forth through a coil of wire, it excited electrons in the wire and generated electrical current.

That first primitive electric generator was the start of a revolution that would transform the world. It led to a modern civilization in which we’ve come to depend upon electricity for myriad uses—from keeping our lights on, our microwave ovens cooking and our refrigerators chilled, to powering our computers, cell phones and TV sets.   

But our voracious consumption of current comes at a price. About two thirds of electricity is still generated by the burning of fossil fuels such as coal and natural gas, and we require gigantic amounts of them to keep the power flowing. Generating the 13,000-kilowatt hours of electricity consumed by each average American, for example, would require a power plant to burn nearly seven tons of coal. Mining and drilling for those fuels causes environmental problems such as water pollution, and burning them for fuel releases vast amounts of planet-warming greenhouse gas emissions into the atmosphere, contributing to potentially catastrophic climate change.

That’s why a new generation of inventors is striving to find cleaner sources of energy to fill our electrical needs. With such a daunting need to fill, they’ve got to think big and bold. To that end, they’re exploring a host of new energy technologies—from more efficient ways to utilize the Sun’s rays, and the Earth’s internal heat, to nuclear fusion reactors and an exotic apparatus that would create artificial, stationary tornadoes to spin power plant turbines. One technology even harnesses microbes to break down waste from a brewery to produce methane for fuel.

Here’s a breakdown of some of the most promising alternative energy projects.

Storing Concentrated Solar Energy: At the Crescent Dunes Solar Energy Project in Tonopa, Nev., an outfit called Solar Reserve is building a plant that will capture, concentrate and store the Sun’s rays. 10,000 computerized mirrors, arranged in a circle, will follow the sun through the sky and reflect solar energy at the top of a 540-foot concrete tower. That concentrated energy will be used to heat 70 million pounds of salt and pump it back down inside the tower into an insulated thermal storage tank, where the molten material can be stored at temperatures of up to 1,050 degrees Fahrenheit with little heat loss. Any time of day or night, the molten salt will be used to create steam and generate electricity to power 75,000 homes, before being recycled back to be heated again.

Fusion Power: Fusion—the combining of atomic nuclei to release energy—is the power source of the Sun and other stars. But scientists have struggled to find a way to harness a fusion reaction, in a way that generates more energy than it takes to create the reaction itself. Some seeming breakthroughs have fizzled. Back in 1989, for example, a University of Utah physicist and his colleague at the University of Southampton in Britain made headlines with claims that they’d produced a net energy gain with a small, tabletop device at room temperature, but ultimately, other labs were unable to duplicate their results. But in the past few years, researchers at the Lawrence Livermore National Laboratory's National Ignition Facility in California have been working on a new method that uses laser beams to compress deuterium and tritium together more densely, which creates particles that create a tremendous amount of energy. But still, that reaction required a lot more energy to create than it produced. If scientists can one day create a fusion reactor that produces more energy than it requires, the world may have an important new energy source.

Harnessing The Earth’s Heat: In 2009, the Icelandic Deep Drilling Project attracted attention by drilling a borehole that accidentally struck a pocket of magma, the hot mixture of molten rock and gases that turns into lava in volcanic eruptions. But the project has a more ambitious goal: Digging shafts several miles down in search of steam that’s been heated by the Earth’s internal heat under such great pressure that it contains enormous amounts of energy. Tapping into that water source would produce 10 times as much power as conventional geothermal energy plants.

Making an Artificial Tornado: Canadian inventor Louis Michaud hopes to develop an atmospheric vortex engine, a machine that would create a permanent, stationary tornado. As warm, moist air, rises inside the manmade vortex, it would turn turbines located at ground level to generate electricity. “A large hurricane produces more energy than all the electricity you produce in a year,” he explains in a video interview. “If you could produce a number of small tornadoes, then effectively we could produce our electricity without producing any greenhouse gas.” While it might seem like a scheme out of a Jules Verne novel, PayPal co-founder Peter Thiel reportedly is in investor in the project, which aims to generate carbon-free electricity at just 3 cents per kilowatt-hour.

Getting More Power From Wind Turbines: SheerWind, a Minnesota-based company, has developed a potentially revolutionary device called INVELOX, which is intended to get more energy out of wind power-generating plants by increasing the velocity of the air that goes through them. According to a 2012 Technology Review article, a tower with multiple ducts captures wind from any direction and then uses a turbine to increase its speed and concentrate its airflow, before passing it through a funnel to a small electricity-generating turbine at ground level. In 2015, Tampa Electric, a Florida utility, announced that it would test a pilot version of INVELOX at its Big Bend Power Station, with an aim to eventually deploying it on a larger scale.

Energy From Beer: Beer companies have found a way to generate alternative energy from waste left over from the brewing process. The material is pumped into a chamber in which microbes break down the biomass to produce methane, which then can be used to run turbines and generate electricity. At Dogfish Head Craft Brewery in Milton, Del., the company uses a GE system to not only recycles wastewater to save 200,000 gallons of water per day, and generates electricity in the process.

Some of these projects may prove to be breakthroughs, while others undoubtedly will turn out to be impractical—or else spawn new, improved ideas. But as a 2014 report by the Intergovernmental Panel on Climate Change noted, it’s urgent for the world to increase its use of cleaner sources of energy, if we’re going have any chance of avoiding drastic climate change.