In the last few years, electric motorcycles have gone from a novelty to serious contenders. The "why" makes sense: tremendous torque and power on demand, low maintenance, and a greener, cleaner vehicle form a compelling package. But the various companies working to make that a reality still have some big challenges in their way.

Editor's note: This is the first in a four-part series on the state of electric motorcycles.

To get a better understanding of how manufacturers are addressing those challenges, and to assess the current state of electric motorcycles, I talked to representatives for Zero Motorcycles, Harley Davidson’s Project Livewire, and Mission Motorcycles to understand their approaches and the differences in their strategies. There are other players, of course, but these three provide a good cross section of the industry.

Zero makes practical bikes for commuters and law enforcement in an urban setting, where quiet operation and not burning fuel while idling at stoplights are advantages, as well as an off-road bike that ends noise issues with motocross in populated areas. Mission is aiming to create the ultimate superbike as a means to showcase the potential of the electric powertrain. And Harley-Davidson is very straightforward about its intent to use the LiveWire to reach out to demographics that wouldn’t buy one of their traditional bikes by creating something totally original and visually striking. (See the TeamZilla report and video on riding the LiveWire.)

The main challenges for the industry are range and refueling. The fact is, batteries are just not as energy-dense as gasoline. Yet. So even though an electric engine is vastly more efficient, getting upwards of 90 percent efficiency, compared to internal-combustion engines (ICE), where 30 percent would be incredible, they’re still handicapped by the bulk and weight of batteries. This forces the manufacturers to choose between range and power. Electric motorcycles don't have the benefit of a century of developing infrastructure to support them, like gas stations for ICE vehicles, so quick and easy refueling is impossible. Therefore, range is critical.

Fortunately, the situation is rapidly changing.

Mission Motorcycles built a high-performance sportbike to showcase the capabilities of the electric drivetrain. The goal is to build lower cost models as volume builds. Mission Motorcycles photo.

As Mark Seeger, the founder of Mission Motorcycles, points out, “the modern battery industry is only 20 years old and only got really going 10 years ago” to serve the needs of the mobile computing sector. According to Abe Askenazi, the CTO at Zero, battery energy density has doubled in the last four years, and the expectation is that it will double again in the next few years, driven by demand from electric vehicles, smartphones, laptops, and so on. Think about how fast computer processors have improved, and then consider what will happen when that same level of R&D gets put into batteries.

Harley-Davidson gained immense publicity with its Project LiveWire, and that was even before the announcement that the electric motorcycle would appear in the Avengers: Age of Ultron movie. Harley-Davidson photo.

The possibility of energy density doubling opens up different potentials for these three different manufacturers. For Zero, it would allow even more customization. The Zero S has four battery packs weighing 40 pounds each. The customer could drop two of those and shed 80 pounds of weight or opt for a full four-battery configuration and boost range and power. Mission's superbike is already one of the fastest production bikes on the planet, and that’s with its engine limited to half its max power. What would that monster look like if they could unleash it? And of course the Harley-Davidson LiveWire is a beast already. Double its range and you have a bike agile and powerful enough to handle urban riding like nothing else the Motor Company has ever produced.

Tune up your motorcycle with your smartphone? The technology of electric motorcycles often appeals to people far more comfortable with their electronic devices than a carburetor. Zero photo. Electric bikes are pushing the envelope in other ways, too. Harley’s LiveWire is a platform to showcase touchscreen displays and other high-end tech the company had developed previously. Zero made headlines by launching a mobile app that lets riders fine tune the performance of their bikes and track battery useage through their smartphones. Mission is taking it a step further and building a motorcycle that can stream data about every aspect of its performance, along with high-definition video. And all electric motorcycles offer ease of tuneability and performance customization that no gasoline-burning bike can match, as well as a simplicity of design that greatly reduces required maintenance. Forget oil changes, spark plugs, valve adjustments and the like. For most electric motorcycles, maintenance mainly consists of new tires and brake pads.

The elephant in the room is that all-electric manufacturers aren’t just trying to carve out a niche. The long-term goal is to replace ICE bikes entirely. That day may be a long way off, but two facts make it almost inevitable. There is a finite amount of petroleum on the planet, so although debate has raged for a long time about when it will become scarce, it will definitely become scarce someday, and other energy sources will have to be used for transportation. Secondly, batteries will only improve. Since battery energy density is the only thing holding back electric bike performance, their time will come.

From that perspective, the LiveWire isn’t just Harley-Davidson’s platform to show off its latest tech to a new demographic. It's also a major motorcycle manufacturer hedging its bets and getting ahead of the curve. Even if, as Ben Lund at Harley-Davidson said, “I can’t see electrics replacing ICE bikes for the foreseeable future.”

Emphasis on “foreseeable.”