Electric-car maker Tesla Motors (NASDAQ:TSLA) is already pushing the limits. It's making cars with up to 270 miles of all-electric range. Will it soon be up to 400 miles after a retrofit package and new battery for the Tesla Roadster? A charging network for long-distance travel within Tesla driving range of 80% of the U.S. population built in just a few years? Nearly 150 miles worth of charge in just 20 minutes?

But this isn't the end of electric-vehicle progress. Tesla's chief technology officer, JB Straubel, recently outlined possibilities for much faster charging.

Model S charging at Supercharger location. Source: Tesla Motors.

From slow to fast to wildly fast
At home, where Model S owners do most of their charging, it takes about nine hours to charge a Model S. Assuming owners plug in their Model S whenever they are at home, this is plenty fast enough to almost always achieve a desired charge rate before every trip. For owners who want a faster charge at home, a second onboard charger paired with a Tesla Wall Connector can provide a full charge in four hours and 30 minutes.

Tesla shows off its charging technology at the Detroit Auto Show. Source: Tesla Motors.

Of course, when Tesla owners are driving long distances, they won't want to wait for four-and-a-half hours. To address this issue, Tesla built a Supercharger network that can serve up a 50% charge in 20 minutes, and an 80% charge in 40 minutes.

While Tesla attempts to locate Superchargers near amenities like bathrooms, Wi-Fi hotspots, restaurants, and shopping centers to make waiting more convenient, it would be ideal to have charging on par with the time it takes to fill a gas tank -- even if owners only have to wait to charge when they are traveling long distances. But this is a pipe dream, right? Not according to Tesla.

A five-minute charge is possible. And we're not talking battery swapping.

"It's going to be hard. But I think we can get [charging] down to five to 10 minutes," Straubel said in an interview with MIT Technology Review. But it's going to take some time before Tesla can offer this charge rate, Straubel noted. He explained that delivering the Supercharger rate of 120 kilowatts of electricity seemed crazy just 10 years ago.

Tesla's Superchargers are already ahead of other charging infrastructure today. Most conventional public charging stations provide deliveries of less than 10 kilowatts. And even the fastest charging from competition still lags behind.

"Even SAE International's brand-new fast-charging standard, which was finalized in October and is being adopted by major automakers such as GM, tops out at 100 kilowatts," notes MIT author Kevin Bullis.

Tapping into solar panels and stationary energy storage
The level of charging Straubel is talking about will likely require solar panels and batteries for storing energy, enabling Tesla to deliver more than 120-kilowatt charging, he told MIT. Some places on electrical grids can't even serve 120-kilowatt charging. And it can be costly to draw such large amounts of power from utilities. Stationary storage and solar panels can help Tesla overcome these challenges.

Tesla has said that it plans to roll out solar panels and stationary storage to Superchargers. In fact, Tesla recently began construction on a solar roof at its Barstow, California, location.

Supercharger in Barstow, California, is getting equipped with solar panels. Photo by Twitter user @TeslaMS60, used with permission.

Could these solar panels one day enable the five-to-10-minute charging Straubel predicts?

If there comes a day when EV owners not only wake up each morning with their desired charge, but find "filling up" on a long-distance trip is also just as convenient as it is for gas-powered cars, the value proposition for EVs may become difficult to pass up for many. Add in Tesla's lower-cost Model 3, aimed for a 2017 launch, and the case for EVs just keeps getting stronger.