"We have this handy fusion reactor in the sky called the sun. We don't have to do anything. It just works," Elon Musk said at the Powerwall debut event.
Elon Musk wants to put the whole U.S. on solar — starting with Tesla's Powerwalls, which are giant batteries that charge with solar power. It makes sense. Solar power can replace a lot of what we traditionally use fossil fuels for, from driving to flying.
See what you can do with solar power:
So what can you power with the sun these days?
IMAGE DISTRIBUTED FOR NRG - A young "Superhero" looks on as cell phones are charged on the new NRG Energy Street Charge portable power charging station at the Houston Children's Museum in on Thursday, June 18, 2015 in Houston. The unit was delivered today and charges mobile phones and is powered by solar energy. (Photo by Scott Dalton/Invision for NRG/AP Images)
A portable solar panel outside of a backpack on the grass of a park along with other technological devices
Students install photovoltaic panels on September 24, 2015 in Ungersheim, eastern France. AFP PHOTO / SEBASTIEN BOZON (Photo credit should read SEBASTIEN BOZON/AFP/Getty Images)
BELFAST, ME - AUGUST 6: An energy efficiency program in Belfast led to this 180-panel solar array atop the city's fire department roof and might yet include, pending city council consideration, a solar installation at an old landfill that, together with the fire department array, would provide 20 percent of Belfast's electricity needs. (Photo by Gregory Rec/Portland Press Herald via Getty Images)
The prototype of the hybrid platfom PH4S which combines renewable energy from solar, wind, wave and tidal sources, is launched on the port of Saint Nazaire on July 17, 2015. The pilot platform includes a wind turbine, solar panels, a tidal turbine and a wave power system capturing the energy of currents and waves. AFP PHOTO / GEORGES GOBET (Photo credit should read GEORGES GOBET/AFP/Getty Images)
In this Oct. 1, 2015 photo, solar panels are displayed for sale at a market in New Delhi, India. India plans a fivefold boost in renewable energy capacity in the next five years to 175 gigawatts, including solar power, wind, biomass and small hydropower dams. (AP Photo/Saurabh Das)
Swiss-made Solar Impulse-2 takes off from Ahmadabad, India, Wednesday, March 18, 2015. The solar powered aircraft is Wednesday headed to the northern Indian city of Varanasi on the third leg of itsâ historic round-the-world trip. (AP Photo/Ajit Solanki)
In this April 20, 2015 photo, David Cunnigham shows a prototype Tesla battery system that powers his Foster City, Calif. home. Cunnigham installed the battery late last year to pair with his solar panels as part of a pilot program run by the California Public Utilities Commission to test home battery performance. Tesla is expected to unveil a stationary battery for homeowners and businesses on Thursday, April 30, 2015. (AP Photo/Jeff Chiu)
A green solarbox stands next to a red phone box as a tour bus drives past in central London, Wednesday, Oct. 8, 2014. Solarboxes are disused telephone boxes transformed into free solar powered charging points for mobile phones. The solarbox, a social enterprise project, is said by its creators to be the first of its kind. (AP Photo/Matt Dunham)
Some of the 300,000 computer-controlled mirrors, each about 7 feet high and 10 feet wide, reflect sunlight to boilers that sit on 459-foot towers. The sun's power is used to heat water in the boilers' tubes and make steam, which in turn drives turbines to create electricity Tuesday, Feb. 11, 2014 in Primm, Nev. The Ivanpah Solar Electric Generating System, sprawling across roughly 5 square miles of federal land near the California-Nevada border, will be opened formally Thursday after years of regulatory and legal tangles. (AP Photo/Chris Carlson)
Discover More Like This
BACK TO SLIDE
Solar Impulse II is attempting a global circumnavigation using just the power derived from the solar cells on its wings. Not exactly a 747 yet, though.
How about plain old electricity? You can get laptops with integrated solar charging built to order.
Or use any one of the solar chargers already on the market to run anything with a USB port.
This extends to the ultimate in redundant, niche products: solar-powered cat toys and solar-powered robots for cleaning your larger solar panels.
Solar power works even better in space than it does on Earth because there's no interference from the atmosphere. The International Space Station? It runs on the sun.
NASA has even toyed with the idea of harnessing energy in orbit and beaming it back down to Earth via microwave or laser. Nothing has come of the concept yet, though, because at the moment, it's still not cost-effective.
Guess we're stuck with plain old rooftop solar panels for now.