The Karma Revero is Green Car Journal’s 2018 Luxury Green Car of the Year, earning this distinction for many reasons. But let's start here: The Revero is the most head-turning vehicle we have ever driven. Period. The attention this stunning grand touring car gets wherever it is driven is just short of amazing. If you’re lucky enough to own one, get used to it. This will never change.
Karma Automotive, a company owned by China’s Wanxiang Group, has revived the impressive but short-lived Fisker Karma extended range electric car that made a brief appearance on the market five years ago, thoroughly reengineered it, and has reintroduced it as the ‘Revero.’ The company wisely left most of the car’s breathtaking exterior design intact with a few tweaks, devoting its efforts instead to major technology improvements and creating a wondrous interior to complement the car’s incredible looks. The company then strategically set up its headquarters and manufacturing in Southern California, the land of electric cars. Even in California, where car culture is king and there’s no shortage of coolness on wheels, this car is clearly special.
The $130,000 Karma Revero is built on a lightweight aluminum spaceframe and powered by two high-power electric motors, both energized by lithium-ion batteries positioned along the car’s centerline. This pair of AC permanent magnet motors provides a combined 403 horsepower and 981 lb-ft torque driving the rear wheels, delivering a 0-60 mph sprint in 5.4 seconds.
Like the Chevrolet Volt, the Karma Revero is a series hybrid that uses an internal combustion engine solely to drive a generator, which in turn supplies electricity to the electric drive motors or to the car’s battery pack. There is no mechanical connection between the engine and wheels. The Revero delivers an estimated 50 miles on batteries alone and about 300 miles total on batteries and electricity generated by its engine-generator.
The Revero’s battery pack can be fully charged in about 10 hours using the car’s onboard charger operating on 120-volt household power. With a 240-volt charger this drops down to just under four hours. A 480-volt rapid charger enables charging to 80 percent of the battery’s capacity in just 24 minutes. The Revero has a large solar roof that’s claimed to contribute up to 1.5 miles of battery power per day, depending on weather conditions. This feature makes the Revero the first production car in the country to be powered by electricity, solar, and gasoline.
A driver has three selectable drive modes – Stealth (pure electric), Sustain (gasoline engine/generator or ‘EV later’ mode), and Sport (battery electric plus generator for maximum performance). Stealth mode would ideally be used in town where zero-emission driving is preferred, with a switch to Sustain model outside of town. The latter would maintain the batteries’ state-of-charge to enable zero-emission Stealth driving again when returning to the city. There are three levels of regenerative braking for desired deceleration and massive Brembo brakes for conventional braking.
Revero is well-connected and able to make software updates wirelessly, using Blackberry's Certicom cryptography as an added security layer within QNX-secured two-way data transmission. The Revero has an eight-speaker audio system with Bluetooth connectivity and three USB charging ports. Driver assistance includes lane departure warning and a backup camera. A 12.3-inch-wide multi-configurable driver display is provided along with a 10.2-inch touchscreen-only infotainment system.
The premium ‘green’ car field is expanding with impressive models available from noted domestic and offshore luxury brands. Each has its strengths and customer appeal. In the realm of plug-in hybrids or extended range electric cars where sheer – maybe intoxicating – beauty is at the top of the list, the Karma Revero truly has no peer.
In his 2011 State of the Union address, President Obama set a goal of having one million electric vehicles on the road by 2015. The million EVs would include plug-in hybrids, extended range electric vehicles, and all-electric vehicles. Now that we’re roughly at the halfway point for the 2015 goal, what is the scorecard?
It’s important to note that the goal was rather naively – or perhaps intentionally – based on manufacturer- and media-supplied data on how many electric cars could be built and not from projections of how many people would actually buy them. Unless we’re talking very hot-selling items like the latest Apple iPhone or iPad, sales projections are usually based on projected sales and not made on potential production.
The estimate actually projected 1,222,200 EV units produced including 13,000 commercial vehicles (Ford Transit Connect, Navistar eStar EV, and Newton EV). Another 252,000 included Fisker Karma and Nina models and the Think EV). Think is no longer producing cars and Fisker Automotive has ceased production, although it should reappear because of it's just-announced bankruptcy sale to China's Wanxiang Group..
Sales of the four EVs and PHEVs to date have been far lower than their target numbers, with the Tesla S a lone exception. The million EV goal looks far from being achievable by 2015.
Electric vehicle models not included in President Obama’s estimates, but now on sale, are the Mitsubishi i-MiEV, Honda Fit EV, Fiat 500e, Chevrolet Spark EV, Toyota RAV4 EV, and smart electric drive. Of these, only the i-MiEV is available everywhere in the country. Some others can be considered ‘compliance vehicles’ since they are only offered in very limited ways with the intent to comply with California’s ZEV mandate, which aims at putting over 1.4 million zero emission vehicles on the road by 2025.
Part of the government’s strategy to reach this goal is to offer substantial tax credits to encourage sales. Typically, this includes a federal credit of $7,500 plus state incentives. As of November 2013, 40 states and the District of Columbia have monetary incentives including electric vehicle tax credits and registration fee reductions ranging from $1,000 in Maryland to $6,000 in Colorado. Even with incentives, though, electric sales are not keeping pace with President Obama’s ambitious goals.
Bill Siuru is a retired USAF colonel who has been writing about automotive technology for 45 years. He has a Bachelor degree in automotive engineering, a PhD in mechanical engineering, and has taught engineering at West Point and the U.S. Air Force Academy.
Integrating photovoltaic cells on vehicles is nothing new. In fact, solar-powered race cars have been around for more than 25 years, proving that the power of the sun can indeed provide enough energy to propel a car down the road.
Of course, these cars are ultra-lightweight and plastered with solar cells on every conceivable surface, tasked with carrying just a driver at a constant speed.
While not practical for driving as we know it, they are valuable engineering exercises that helped move the bar in developing electric vehicle efficiencies. Just one example is GM’s Sunraycer solar race car, built under the guidance of the renowned master of efficiencies, the late Paul MacCready of AeroVironment, which won the World Solar Challenge in Australia in 1987.
Lessons learned were applied to the GM Impact electric car prototype – precursor to the GM EV1 – that AeroVironment built under contract for GM and was unveiled by the automaker at the 1990 L.A. Auto Show.
Solar panels were notably integrated on the hood and rear deck of Solar Electric Engineering’s Destiny 2000, an electric car upfitted from a gasoline powered Pontiac Fiero we test drove back in 1994. Today, Audi uses a solar panel on its top-of-the-line A8. Toyota offers an optional Solar Roof package for the Prius.
While some might think these can help power an electric car, their relatively low energy output can realistically do little more than trickle-charge batteries or, more appropriately, power low-demand ventilation systems while an electric car is parked to help keep interior temperatures cooler on hot days without draining the battery.
Today there’s a new champion of solar ingenuity on the road. The Fisker Karma plug-in electric hybrid luxury sedan features probably the most sophisticated solar roof ever offered on a production model, using the world’s largest continuous-formed glass solar panel on an automobile. Not only does it keep the Karma’s interior cool on a hot day, but also supplies electricity to the car’s 12 volt system used for starting and accessories, relieving the high voltage lithium-ion battery system from tapping energy needed for driving. This can increase range, though admittedly a small amount.
To create the large solar panel, 80 small monocrystalline cells are individually hand-laid under automotive safety glass to follow the contours of the roof. The solar panel has four electrically separate zones, each consisting of 20 cells in series. Each of the four zones incorporates MPP (maximum power point) tracking to optimize power output under various solar radiation angles and partial shading conditions. The splayed solar cell array design maximizes solar ray absorption under various lighting conditions, while the graphic accent running between the cells lends a unique and futuristic appearance.
A Karma driver can choose three solar power modes. In the Charging mode, as much solar energy as possible is stored in the battery. When Climate is chosen, solar power is used to ventilate the passenger compartment to reduce the effects of radiant heating. In the default Auto mode, the Karma will use solar power to maximize energy recovery and usage.
On a typical day, the solar panel supplies 0.5 kilowatt-hours of electricity. When used for battery charging, Fisker says over the course of a year that translates to maybe 200 emissions-free miles. That’s free energy, for sure. But how meaningful is that in the scheme of things? Like others before it, the Karma’s solar roof – with its imposing look and obvious green credentials – is a step in the right direction, showcasing innovation and yet another way to embrace renewable energy. It is an environmental friend, with benefits…but it’s hardly a statement that solar powered, highway capable cars are upon us. Still, free energy is, well…free energy…and we like it.
