Written by Catherine Bolgar*

In some ways, the car of the future is a blast from the past.

The electric car was invented more than 100 years ago, but was overtaken in the 1930s by petrol-powered autos.

Electric vehicles (EVs) are getting a second wind as a more sustainable alternative to cars. EVs produce no tailpipe emissions—an important quality because global carbon dioxide emissions from passenger cars and freight transport are forecast to double by 2050 according to the International Transport Forum, with cars accounting for the lion’s share.

While the electricity powering EVs may be generated by fossil fuels, it still pollutes about 40% less than regular cars. And that could be cut by shifting toward renewable energy for the electricity EVs use to charge up.

About 180,000 EVs are on the road today, a drop in the ocean compared with the global fleet of over a billion petrol -powered cars, a number expected to grow to three billion by 2050. The Electric Vehicles Initiative, a forum of 16 countries, hopes to get 20 million EVs on the road by 2020, which would represent 2% of total passenger cars.

In other words, we’re still a long way from the future.

Why are EVs such a hard sell? The advantage of petrol-powered cars is unlimited range, something that has become inseparable from the essence of “automobile”—this thing that lets you go anywhere, at any time. EV ranges run from 70 to 100 miles (112 to 160 kilometers) on a single charge. Statistics show that 95% of vehicle trips in the U.S. are less than 30 miles and that only 1% of trips are more than 70 miles, so current EV range is plenty for most trips.

People cite worries about having to look for a charging station, or that charging will take longer than topping off the gas tank does. However , EVs have advantages.

Drivers are accustomed to a routine of filling their gas tanks weekly, even though it’s smelly and, in bad weather, unpleasant. “One of the conveniences of electric vehicles is you plug it in overnight and don’t have to go to the charging station,” says Don Anair, research director of the clean vehicles program of the Union of Concerned Scientists.

A range of innovations aims to address some of the technical problems.

• Better batteries. Consumer electronics such as smartphones have helped drive advances in battery technology, particularly in improving battery life while reducing size. Auto-makers are shifting to lithium-ion batteries, from nickel-metal hydride batteries. However, researchers continue to chase new technologies, such as lithium-air, silicon alloy anodes, lithium metal graphene-anode and other battery combinations. Already, the cost of batteries for plug-in EVs has dropped by half in the past four years, and the size and weight have shrunk 60%.
• Hydrogen fuel cells. A technology at an early stage of commercialization is EVs powered by hydrogen fuel cells. “It’s a good option for consumers looking for an EV, but who don’t have a place to plug in to charge,” Mr. Anair says.
• Old mixed with new. The hybrid uses both electricity and petrol fuel, with a growing range of choice. At the mostly-petrol-with-a-little-electricity end of the spectrum, conventional hybrids switch to electric in high-consumption situations like traffic jams, with batteries charged by regenerative braking and the gasoline engine. Plug-in hybrids run on the battery and switch to the internal combustion engine when the battery is out of juice. At the mostly-electric end of the spectrum, an EV with a range extender keeps powering the wheels from the battery while a small gas motor charges the battery enough to run the car farther. A range extender allows for a lighter-weight battery, which helps improve efficiency.

The first battery-powered vehicles with range extenders are on the market. BMW’s electric vehicle, the i3, now has an optional range extender that adds up to 75 miles of driving on a charge. General Motors has added a range extender to the Chevrolet Volt and Opel Ampera.

In the future, consumers will have more choices of low-carbon vehicles to drive,” Mr. Anair says.

• Lighter vehicles. Reducing weight, whether for EVs or conventional vehicles, improves efficiency. The internal combustion engine burns fuel to make power, but only 25% to 30% of the energy in a gallon of gasoline turns the car’s wheels, while the rest is lost as heat, explains Lawrence Burns, professor of engineering practice at the University of Michigan. If the driver weighs 150 pounds (68 kilograms) and the car weighs 3,000 pounds, then only about 1% of the energy is being used to move the driver. “We have to get vehicles more in line with our body weight,” he says.

Lighter materials such as aluminum, carbon fiber, magnesium, composites and steel alloys are gaining favor already, as a way to meet fuel efficiency requirements. Ford’s new F-150 pickup truck , for example, now has an aluminum body, reducing the weight by 700 pounds.

With nanotechnology, we are able to create new types of materials with new products,” Dr. Burns says.

One reason why consumers shy from lightweight or small vehicles is how they withstand crashes. In the future, connected and driverless vehicles will improve traffic flow and reduce accidents. “We can have cars that don’t crash, so we can get mass out of the car,” Dr. Burns explains.

Connectivity and big data could help in another way: by improving systems for people to share vehicles and to deliver goods more efficiently. A global shift away from cars could save $100 trillion, cut 40% of urban passenger transport emissions and avoid 1.4 million early deaths by 2050, according to a new study.

We not only need to improve the vehicles or fuels, but also to think of the whole transport system and how you can improve services in passenger transport and logistics, making use of information and communications technology,” says Nils-Olof Nylund, research professor at VTT Technical Research Center of Finland, which has launched a program to make Finland a model country for sustainable transport by 2020.

In looking at mobility as a service, the goal is to reduce the need for cars and instead increase public transport, walking and biking, he says. Key to public transport are frequency and communication—people don’t like to wait for public transport, especially in bad weather. Knowing exactly when the bus will arrive, thanks to a smartphone app, can eliminate that barrier.

In addition, buses, which run along fixed routes on fixed schedules, are ideal for electrification—charging stations can be located on the routes, Dr. Nylund says.

What I see coming is not one thing but a combination of connected, shared, driverless, tailored vehicles, combined with business models focused on selling miles, trips and experiences, not just cars, gasoline and insurance,” Dr. Burns says. “Technologically, I don’t think there’s anything that stops us from having a dramatically more sustainable transportation system than in the past.”

*For more from Catherine, contributors from the Economist Intelligence Unit along with industry experts, join The Future Realities discussion.