2015’s Top Ten Tech Cars: Toyota Mirai

Doubling down on hydrogen fuel cells

2 min read
2015’s Top Ten Tech Cars: Toyota Mirai
Photo: Toyota

Video: moteur nature

Is it a Mirai or a mirage? Skepticism is necessary with hydrogen-fuel-cell cars. Dazzled by the promise of tailpipes that emit only water vapor, a generous driving range, and fill-ups within minutes, people often overlook the downsides: hardly any places to refuel and very high costs for both fuel and vehicles. But like Jason in the Halloween movies, hydrogen is ba-aaack, with several automakers insisting that they’re this close to putting hydrogen cars in showrooms.

The Mirai is the latest trial balloon, coming to California in late 2015 in small volumes at US $58,325 (or about $45,000 after tax incentives). Fuel-cell cars are basically electric cars that replace the battery with a fuel stack that generates electricity via a one-way chemical reaction fueled by hydrogen; when the hydrogen runs out, you pump more in. Pressurized hydrogen reacts with a catalyst (usually platinum); electrons are stripped from hydrogen molecules to power an electric motor; freed protons then recombine with oxygen in the stack, creating good old H20, which helps cool the fuel stack before exiting the tailpipe.

Price: US $58,325

Power train: 113-kW (151-hp) hydrogen fuel cell with AC motor

Overall fuel economy (est.): energy equivalent of 3.9 L/100 km (60 mpge)

Enter the Mirai, the fruit of 20 years of Toyota fuel-cell R&D. Mirai means “future” in Japanese, but hopefully fuel-cell cars won’t all be as aggressively frumpy as this Toyota. Looks aside, the Mirai leaps forward in technology: Toyota says the fuel stack packs 3.1 kilowatts per liter, more than twice the power density at a mere 5 percent of the total cost of its 2008 prototype. That stack of 370 fuel cells weighs just 56 kilograms (123 pounds) and powers an AC electric motor with 113 kilowatts (151 horsepower) and 335 newton meters (247 foot-pounds) of torque—good for a reasonable 9.0-second run to 97 kilometers per hour (60 miles per hour).

The Mirai stuffs 5 kilograms of hydrogen into a pair of carbon-fiber-reinforced tanks at 69,000 kilopascals (10,000 pounds per square inch). That’s the energy equivalent of 19 liters (5 gallons) of gasoline, enough to travel 483 kilometers (300 miles)—about three times the range of a typical electric vehicle. One neat bit is a DC outlet that allows you to tap up to 60 kilowatt-hours when the Mirai is stationary; with a full tank you can power a typical household for six days. Survivalists, take note.

In the United States, the company will offer a $499-per-month lease with $3,700 down. Toyota expects about 200 people in the United States, and 500 more worldwide, to early-adopt this hydrogen baby in 2015. Global production is pegged in the tens of thousands after 2020. To that end, Toyota and the state of California are backing construction of up to 48 hydrogen stations by the end of 2016, with a dozen more planned in U.S. northeastern states. It’s a start. To spur development of the technology, Toyota announced it will allow royalty-free use of nearly 5,700 fuel-cell patents around the world.

The Conversation (0)

The Hyperloop Is Hyper Old

Elon Musk merely renamed a 200-year-old dream

3 min read
Illustration of a tube and various ways of moving vehicles.

William Heath's 1829 engraving pokes fun at a vacuum tube that conveys travelers from London to Bengal.

Universal Images Group/Getty Images

"Lord how this world improves as we grow older," reads the caption for a panel in the " March of Intellect," part of a series of colored etchings published between 1825 and 1829. The artist, William Heath (1794–1840), shows many futuristic contraptions, including a four-wheeled steam-powered horse called Velocity, a suspension bridge from Cape Town to Bengal, a gun-carrying platform lifted by four balloons, and a giant winged flying fish conveying convicts from England to New South Wales, in Australia. But the main object is a massive, seamless metallic tube taking travelers from East London's Greenwich Hill to Bengal, courtesy of the Grand Vacuum Tube Company.

Keep Reading ↓ Show less

SambaNova CEO: “We’re Built for Large”

Rodrigo Liang explains the $5-billion AI startup’s philosophy and future

8 min read
SambaNova CEO, Rodrigo Liang

SambaNova CEO, Rodrigo Liang

SambaNova

AI, particularly the huge neural networks that meant to understand and interact with us humans, is not a natural fit for computer architectures that have dominated for decades. A host of startups recognized this in time to develop chips and sometimes the computers they'd power. Among them, Palo Alto-based SambaNova Systems is a standout. This summer the startup passed US $1 billion in venture funding to value the company at $5 billion. It aims to tackle the largest neural networks that require the most data using a custom-built stack of technology that includes the software, computer system, and processor, selling its use as a service instead of a package. IEEE Spectrum spoke to SambaNova CEO Rodrigo Liang in October 2021.

Rodrigo Liang on…

Keep Reading ↓ Show less

EP29LPSP: Applications in Plasma Physics, Astronomy, and Highway Engineering

Ideal for demanding cryogenic environments, two-part EP29LPSP can withstand temperatures as low as 4K

3 min read

Since its introduction in 1978, Master Bond EP29LPSP has been the epoxy compound of choice in a variety of challenging applications. Ideal for demanding cryogenic environments, two-part EP29LPSP can withstand temperatures as low as 4K and can resist cryogenic shock when, for instance, it is cooled from room temperature to cryogenic temperatures within a 5-10 minute window. Optically clear EP29LPSP has superior physical strength, electrical insulation, and chemical resistance properties. It also meets NASA low outgassing requirements and exhibits a low exotherm during cure. This low viscosity compound is easy to apply and bonds well to metals, glass, ceramics, and many different plastics. Curable at room temperature, EP29LPSP attains its best results when cured at 130-165°F for 6-8 hours.

In over a dozen published research articles, patents, and manufacturers' specifications, scientists and engineers have identified EP29LPSP for use in their applications due to its unparalleled performance in one or more areas. Table 1 highlights several commercial and research applications that use Master Bond EP29LPSP. Table 2 summarizes several patents that reference EP29LPSP. Following each table are brief descriptions of the role Master Bond EP29LPSP plays in each application or invention.

Keep Reading ↓ Show less