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An “electric” concept car due here in 2012: the Chevrolet T he Sydney International Motor Show has come and gone, under a blaze of spotlights and almost continual buffing fingerprints off paintwork and glass. Of course, the Ferraris and Lamborghinis earned lots of “oohs” and “aahs” from the admiring crowds (and probably thoughts of “when I win Lotto . . .”). But it was the more everyday, perhaps even prosaic vehicles which attracted the most attention. Maybe it was the economic climate There was plenty for the rev-heads but this year the theme seemed to be a definite shade of light about 550nm in wavelength (OK, green for the uninitiated). 12  Silicon Chip Many manufacturers featured small, efficient diesels (remember not too long ago when “Diesel” was a dirty word?). Hybrids also seemed to be the order of the day, with several manufacturers offering their particular variants. The Toyota stand had them stacked up the wall and sitting at 45°angles, as well as rotating in front of you. Toyota’s Hybrid Synergy Drive (Oh What a Feeling!) was everywhere, even in the flashing LED and LCD signs (printed signs, such as featured on the Ford display next door, are so passé). But there was little to differentiate the new Camry’s propulsion system from the new Prius propulsion system. It’s a hybrid. Honda had their Insight, which was no different to last year’s Honda Insight (or the year before’s, if you believed the salesman). “But there’s a new one coming soon,” he said. How soon? “Ummm – next year?” Even Lexus had their up-market hybrids alongside their new LF-Xh concept car (which has a V6 engine plus an electric motor driving all four wheels). While Toyota’s Prius has claimed the prized top-of-mind position when it comes to hybrids, Lexus has sold more than 2000 of their up-market hybrids in the past two-and-a-bit years. siliconchip.com.au Star of the Sydney International Motor Show? Volt Mazda had their striking “Taiki” concept car on display with its completely-enclosed rear wheels. Like most concept cars, this one is very unlikely to see the light of a showroom but Mazda (like all concept car producers) maintain that many of the design elements in the Taiki will emerge in the next generation of street models. When saving energy is right at the top of a designer’s wish list, the Taiki’s 0.25 drag coefficient cannot be ignored. But then again, neither can its shape. Nissan again featured their Mixim electric vehicle but this was not particularly newsworthy – it’s been seen before. siliconchip.com.au Something that has not been seen before (at least in Australia) was taking pride of place on the GM-H stand: the Holden (or perhaps I should say Chevy) Volt. Will it be a Holden when it eventually reaches our shores? Now here was something different, something worth a lot closer look. The Chevy Volt This is a vehicle based on a whole new design philosophy, one that has attracted a lot of comment in the media and on the web. It is an EREV – an Extended Range Electric Vehicle – which marries several different genres. by Ross Tester First and foremost, the Volt is a true electric vehicle – the wheels are driven solely by an electric motor, powered by a bank of on-board batteries which are in turn charged overnight from the mains supply. But it also contains a small, efficient, internal combustion engine (ICE), so does that make it a hybrid? No, because in a hybrid the ICE can also power the wheels. In the Volt, it cannot: the ICE is solely responsible for charging the battery when it reaches its limit of about 60km. The ICE is where the EREV part comes in – the motor extends the range up to 400km. December 2008  13 The small tank on the left is the fuel tank for the on-board generator. It sits on top of the rail containing the top of the battery bank. You’ve probably picked up on that 60km basic electric range. GM’s research suggests that 75% of commuters (at least in the US) travel less than 40 miles (64km ) each day, so they designed what amounts to a “town car” to precisely target this market. In this use, most of the time the ICE will never cut in but it takes away the so-called “range anxiety” which drivers of electric-only cars face: “what do I do when the battery runs out and I Engine Generator Electric Drive Unit am stranded miles away from home/a power outlet/etc?”. Another concept car In truth, the Volt is also a concept car – a car that never was, nor will ever (probably) be. The plan is to release a Chevrolet Volt in the USA in late (November) 2010 and then in Australia sometime in 2012 but the odds are a million-to-one on that it won’t be this exact vehicle. For a start, according to GM’s own press releases, they have yet to determine which battery manufacturer will get the nod. At the moment there are three manufacturers vying for what will be a very lucrative contract. But more on the battery shortly. There’s also the engine: some reports suggest that the engine in the display model Chevy Volt is no more than an electric golf cart motor capable of moving it around “a bit”. In conjunction with some major players and many minor ones, GM are still developing much of the “important” bits – like motors and batteries! However, GM have said that the Volt chassis, look and running gear is probably very close to what will appear on US (and then world) roads. The engine We cannot tell you much about the electric engine because the final design hasn’t been chosen yet. However, GM are looking toward a motor with the equivalent of 150hp/110kW, 370Nm of instant torque (you gotta love electric acceleration!) and a top speed of – wait for it – 160km/h. This seems to be a bit of an enigma: if you’re designing a town car with limited range for commuters, why give it freeway top speeds? Because they can? Lithium-Ion Battery Charge Port Here’s a chassis-only view of the Chevy Volt. Note the T-shaped battery (shown here in blue). Our first reaction when seeing this diagram was “why not add more batteries for longer range?” 14  Silicon Chip siliconchip.com.au A couple of snaps of the display model Volt at the Motor Show. Above, a cutaway showing part of the battery pack (ignore the black thing above it – that’s a large Plasma screen to extoll the Volt’s virtues!). At right is what will be the motor and control units (at the moment, the motor is from a golf cart!). However, if other electric cars are any yardstick, with a top speed of 160km/h, idling along in city traffic should dramatically increase range but GM have made no comment on this. The ICE generator is highly efficient, having just one task – turn a generator. Therefore its power band and operating parameters can be maximised, unlike a normal petrol (or even diesel) engine which must be able to power a vehicle from rest to top speed under various loads and therefore is a compromise. The motor appears to have already been chosen, with a model capable of running on either straight petrol or anything up to 85% ethanol blend. The fuel tank in the concept vehicle is tiny, appearing to be not much more than about 25 litres in capacity. The battery and charging Obviously, the battery is the most important part of any electric (or even hybrid) vehicle. In the Volt, we know that (at least currently) the battery will be a T-shaped, 16kWh Lithium-Ion type, consisting of more than 220 cells. GM are very close-lipped about the actual make-up of the battery but reports we have seen suggest that they are working on a design with a 3-phase 320V AC motor, so that gives some indication of battery voltage. The batteries run along the centreline of the body and out towards the back wheels. The batteries are not allowed to discharge below 30% – that’s when the ICE generator cuts in, or you start to charge it from the AC mains via its on-board, intelligent charger. GM claim that it will be possible to charge the battery in less than three siliconchip.com.au hours “from a standard 110 or 230V household outlet”. That’s a rather hefty charging current – about 16A or so by our calculation (16kWh x 70% /3 hours = 3.73kW per hour; 3730/230 = 16.2A). Add in the inefficiencies in both the charger and the actual charging (say 85% each) and that adds up to more than 22A. We’re thinking that the vast majority of users will want to charge the Volt from cheaper off-peak power (or whatever it’s called in a few years) so they will need to have a special outlet installed anyway. And yes, we’ve checked: you are allowed to use off-peak power to charge a battery, even one in an electric vehicle! Cost to charge At current Sydney off-peak rates (5.83c/kwh) it’s going to cost the best part of a dollar to charge the Volt (16kWh x 5.83c). Worst-case scenario (with PowerSmart Peak <at> 30.25c/kWh) that would jump to around $4.80. Remember, this gives you about 60km of “all electric” driving. GM’s costing is around $2.00 for a night-time charge and on their figures, that 75% “average 60km commute” would result in cost savings of about $4400 annually (Australian dollars). Obviously, without tests, this figure can neither be confirmed nor denied and just as obviously, doesn’t take into account any battery replacement costs. Otherwise, you would expect operating costs of the Volt to be lower than a conventional petrol-powered car as service costs should be lower for a petrol engine that works only a small percentage of the time. Incidentally, GM claim that the Volt will cost around 4c per kilometre to run electrically versus about 24c/ km for an equivalent-sized petrolpowered vehicle. The vehicle The Volt is a front-wheel drive, fourpassenger model that from the outside, simply looks like a modern car. However, significant attention has been made to getting the body shape just right to achieve the lowest coefficient of drag – wind resistance – thus maximising range. This is a feature of most modern passenger car design, certainly not limited to the Volt. It also uses specially-developed, lowprofile, low-rolling resistance tyres on 17-inch rims, again to minimise drag and therefore range. Many of the design cues from the concept vehicle will endure in the production Volt, including the closed front grille, athletic stance, rear design graphics, outside rearview mirrors and more. The Volt’s rounded and flush front fascia, tapered corners and grille are functional, enabling air to move easily around the car. At the rear, sharp edges and a carefully designed spoiler allow the air to flow off and away quickly. An aggressive rake on the windshield and rear screen help reduce turbulence and drag. Inside, the Volt will offer the space, comfort, convenience and safety features that customers expect in a fourpassenger sedan and it will deliver them in a variety of interior color, lighting and trim options unlike any offered before on a Chevrolet sedan. Modern controls and attractive materials, two informational displays and a touch-sensitive “infotainment” centre with integrated shifter will distinguish the Volt’s interior from other vehicles on the market. Some of Volt’s interior technological December 2008  15 Preliminary Specifications General Vehicle Type: Category: E-REV Competitors: Chassis: Seating Capacity: Performance Top Speed: EV Range, City (km): 5-door, front-wheel-drive sedan. Extended-Range Electric Vehicle (E-REV). None. Independent MacPherson struts front, compound crank twist axle rear, four-wheel disc brakes, full regenerative brakes to maximise energy capture, electric power-assist steering. Four. 160km/h 64km Dimensions Wheelbase: Length: Width: Height: Cargo Volume: 2685mm 4404mm 1798mm 1430mm 301L Battery System Type: Energy (kWh): Lithium-ion. 16 Electric Drive Unit Power (kW / hp): Torque (Nm / lb-ft ): 111 / 150 370 / 273 Exterior Tyre and Wheel Size: Specially developed low rolling-resistance tyres on 17-inch aluminium wheels. features will include: • Driver-configurable, liquid crystal instrument display. • Standard seven-inch touch screen vehicle information display. • Touch screen-style climate and “infotainment” controls. • Optional navigation system with onboard hard drive for maps and music storage • Standard Bluetooth for cellular phone and USB/Bluetooth for music streaming Driving the Volt will take some getting used to – there will be virtually no noise from the electric motor and even when the ICE generator fires up, its noise level will be way below conventional vehicles. Acceleration may also catch some drivers by surprise! Green power? A lot of argument about the “greenness” of the Chevy Volt has centred on its power source. The argument goes that by taking power from the grid to charge an electric car, one is simply transferring pollution from the exhaust pipe of the car to the exhaust stack of the power station. GM is quick to point out that a lot 16  Silicon Chip of electricity generation in the USA (27% by some reports) is from noncoal-fired sources and even then, modern coal-fired power stations are much better in the pollution department than previously. By taking large numbers of petrolpowered vehicles off the road and making them electric, they maintain there will be more incentive to make electric power generation cleaner and the atmosphere will also be cleaner from less vehicle pollution. A good argument? Only time will tell! Translate that to Australian dollars (which may be up, down or sideways by 2012) and you are paying a very high premium for an electric vehicle. If it was me, I’d be with many of the web commenters: “I’d love one, but SC not at that price. . .” How much? The Chevy Volt initially had a target price of $US30,000. By GM’s own admission, even now (two years before its release) that price has blown out to $US48,000 (almost $AU70,000 at time of writing but who knows!). Whether this cuts out a significant portion of the market for GM is already causing a lot of discussion on the web, with many people raising serious concerns about the price increase (and remember, like-for-like US new car prices are on the whole significantly cheaper than ours). Oh, what a feeling: Toyota’s stand had their Camry hybrids stacked like Matchbox toys! siliconchip.com.au