Just as no credible scientist questions whether the world is getting warmer, no credible automotive engineer questions whether electric vehicles (EVs) are more energy efficient than internal combustion engine vehicles or hybrids. The automotive industry, which for years experimented with hydrogen fuel cells, biofuels and other alternatives, has reached a clear consensus: the future is electric.

Even in the worst-case scenario, where electricity is generated primarily from coal-fired power plants, the Tesla Roadster EV is about twice as energy efficient as a Toyota Prius and produces far fewer greenhouse gas emissions than any petrol-powered sports car. In a best-case scenario, the Roadster consumes entirely renewable energy; the owner can live "off the grid" with a car that does 0-60mph in 3.9 seconds.

Supercar performance from renewable energy is not a pipe dream. Many enthusiasts are already using energy stored in their homes' solar panels to power their Roadsters. They're making a conscious choice to invest in a company that is relentlessly driving down the cost of EV technology.

The new Tesla Model S all-electric sedan car at its unveiling in California last month. Photograph: Robyn Beck/AFP/Getty Images

Just last month, Tesla unveiled the Model S, a family sedan that seats five adults and two children and has a range of up to 300 miles per charge. The base price, with a battery pack that gets 160 miles per charge, is roughly half that of the £94,000 Roadster. If you account for the cost advantage over the life of the car compared with a four-door petrol car assuming a petrol price of £2.35 per gallon, the Model S is equivalent to a conventionally powered car with a sticker price of about £23,000.

Tesla also sells powertrain components to other automakers. Far from keeping a lock on the technology, Tesla is actively helping competitors develop more affordable EVs and get them to customers faster. Tesla works closely with Germany's Daimler (Mercedes-Benz's parent company) and is developing a fleet of electric Smart microcars for zero-emission urban commuting.

As Tesla amortises research and development costs, we are simultaneously swimming in the slipstream of the decreasing cost curve of lithium-ion battery cells. For more than a decade, Li-ion costs have decreased conservatively 8-10% per year. Such patterns are well known in Silicon Valley, where other technology companies helped transform cell phones, laptop computers and flat-screen televisions into mainstream commodities.

Tesla has already delivered more than 350 cars to customers, and about 1,000 more people are on the Roadster waiting list. There's clearly pent-up demand for a green car that outperforms Porsches and Ferraris. And with more than 700 reservations for the Model S in the first two weeks after its launch, we're learning that demand for more affordable EVs is even stronger than we expected.

Toyota introduced the Prius more than a decade ago. Since then, rivals have launched competing products, yet Toyota retains by far the largest hybrid market share.

Automakers are now busy making EV and range-extended EV prototypes; the industry is racing to democratise EVs. We will get there, but only with help from affluent early adopters.

The Tesla Roadster is recharged. Photograph: Getty



• Elon Musk is Telsa Motors' CEO, chairman and product architect