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Flywheels Could Be Cheap Way To Slash Fuel Use In Cars

Volvo Flywheel

 “The technology will allow (vehicle manufacturers) to significantly reduce CO2 emissions for a fraction of the cost and weight of conventional electric hybrids”

The conventional wisdom, boosted by government subsidies, suggests electrification is the only way to curb fuel use in cars, but flywheel technology could be a cheaper and more environmentally-friendly way to enhance the efficiency of internal combustion engines.

That’s the view of Jeremy Deering, chief executive of Torotrak Plc, a British engineering company pushing its own flywheel technology.

Deering, in an interview, said there is a bias in favor of electric vehicles by those who see this solution as a “magic bullet” for CO2 reduction, and this is crowding out alternative technologies.

Whole life emissions of electric vehicles, which include the impact of recycling dangerous metals, show little advantage, if any, over the most efficient internal combustion engines. In Europe, the regulatory regime offers car manufacturers incentives to cut fuel use, but only via electric solutions.

In some European countries, governments offer up to about $8,000 towards the price of a battery-only car. In the U.S. this can reach $7,500.

Deering said regulations which seek to help battery-only cars, plug-in hybrids, and gasoline-electric hybrids, should be changed to allow fly-wheel technology to get a boost as well.

“Electric vehicles can have higher CO2 emissions than an equivalent type with an efficient internal combustion engine, when measured over their entire life cycle, but current regulations do not recognize this. The result is that electric solutions are portrayed as zero-polluters and attract enormous investment that steers funding away from potentially more effective and near-term solutions,” Deering said.

“Electric vehicles have a major role to play in a future low carbon transport system, but this should be alongside other technologies, such as improved internal combustion engines and mechanical flywheel hybrids,” Deering said.

In an article earlier this year in the Wall Street Journal, Bjorn Lomborg, author of the Skeptical Environmentalist, pointed out that a regular battery car like the Nissan Leaf had already a virtual 80,000 miles on the CO2 clock while sitting in the showroom, mainly because of the energy-intensive methods used to produce the battery.

This compares with under 40,000 miles worth of CO2 for a comparable car with an internal combustion engine. During its lifetime, a battery-only car may start to narrow the gap with regular cars, but this will be slowed if the electricity is generated by coal, oil or even natural gas. Nuclear, hydro or renewable electricity generation is required for green targets to be achieved, and that only really happens in France, with its high proportion of nuclear generation, Switzerland’s hydro output and Denmark’s wind power.

End of life recycling of batteries and other components is another huge penalty for the so-called “green” solution”. Lomborg said for electric cars to win the “green” race they need to clock up high mileage, but another inconvenient fact stands in the way; batteries lose power with age, and a Leaf’s range will be cut from the 73-mile U.S. rated initial capacity to about 55 miles after five years.

So there appears to be room for other technologies, like fuel cells, or mechanical solutions like flywheels.

Volvo Flywheel.1Flywheel technology recaptures power by spinning at up to 60,000 revolutions per minute as the car free-wheels or brakes and can be unleashed for overtaking, or stored in the battery to extend range. Early uses will be seen in buses, trams and light rail vehicles, and will soon be appearing in luxury vehicles like sports cars and SUVs. Grand Prix specialist Williams Racing has tested the technology on a specially adapted sports car, the Porsche 918 RSR Hybrid on circuits such as Laguna Seca in Monterey, California and the Nurburgring circuit in Germany. Volvo has tested its S60 with a flywheel system, and was impressed with the results, although it didn’t say when this might appear on its vehicles for sale.

Torotrak has bought a 20 per cent stake in flywheel hybrid developer Flybrid Automotive. Flybrid has developed the Mechanical Kinetic Energy Recovery System, which Torotrak says can recover up to 70 per cent of braking energy for around a third the cost of battery electric hybrids.

“The technology will allow (vehicle manufacturers) to significantly reduce CO2 emissions for a fraction of the cost and weight of conventional electric hybrids,” Deering said.

Torotrak quoted from a report it commissioned by industry consultants Ricardo on the benefits of fly-wheels.

“The purely mechanical flywheel system also eliminates the cost and price instability of exotic metals, and the end of life costs of batteries,” Ricardo said.

Ricardo estimated the market penetration possibility of 0.4 per cent to 3.8 per cent by 2020, offering potential sales of up to four million a year.

Manufacturers in Europe and the U.S. are desperately trying to slash the fuel consumption of their vehicles to meet ever tightening regulations. In the U.S., average fuel consumption of new cars must be cut to 54.5 miles per U.S. gallon by 2025. In Europe, the regime is even harsher, with regulations calling for a 43 mpg average by 2015, and close to 60 miles per U.S. gallon by 2021. The rules for 2021 in Europe include so-called “supercredits” which allow electric and plug-in hybrids to count up to three times as much towards the average as regular cars, allowing top-of-the-range profit generating big cars from the likes of BMW, Mercedes, Audi and Porsche to continue to be sold.

Torotrak wants the regulations to give credit to fuel saving from its mechanical flywheel system.

According to International Strategy and Investment (ISI) analyst Arndt Ellinghorst, European manufacturers face cumulative costs of $16.5 billion to comply with these rules. ISI calculates that European mass car manufacturers generate roughly $275 to $413 of profit per vehicle and the E.U. CO2 rules will add $1,375 to the cost of every car.

The E.U. regulations are expressed in grams of CO2 generated per kilometre (g/km). The target for 2015 was an average of 130 g/km, which most manufacturers have already reached. The 95 g/km target for 2021 though represents a massive obstacle.

“The distance to 95 g/km is, however, very significant; 95 g/km equates to average fuel consumption of (57.4 mpg). Unsurprisingly, future cost curves are upward sloping with much of the low-hanging fruit already harvested. Thanks to the law of diminishing returns, material improvements in fuel economy will become harder. Light weight materials, further improvements in internal combustion engines and electrified power trains will be needed,” Ellinghorst said in a recent report.

This is where Torotrak’s technology should get a boost.

“(Car manufacturers) are in the process of approaching the E.U. authorities for equal treatment of flywheels for (supercredit) incentives. We want mechanical solutions like flywheels to have equal status with supercredits as solutions for efficiently reducing CO2. We don’t see why we shouldn’t be granted that status, and this would accelerate use of our technology,” Deering said.

Current electric solutions are too pricey.

“Electric is too expensive. And there is the range problem. The answer is a combination of different things. Engines have to get a lot smaller and more efficient; there’s a  huge amount that can be done to reduce size. I’m not saying that electric cars don’t have a place because they do, it’s a question of getting the balance right. We need more diversity and open mindedness of approach,” Deering said.

“Our fly-wheel system will be going into buses and we are talking to car makers about it. It costs about a quarter of an electric solution,” Deering said, without naming the possible car companies.

Enough is enough
This hugely expensive drive to force car manufacturers to slash fuel use made sense a few years ago, when most experts predicted an end to supplies of fossil fuels within a short timescale. But recent new fracking technology for oil and gas has eliminated the fear of running out of fuel.

According to the Paris-based International Energy Agency (IEA), gas-fracking could double the world’s available supply of natural gas and extend supply at current rates of use to over 250 years from the earlier estimated 120 years of conventional supply. When this report was published last year, the I.E.A said U.S. production of oil was set to overtake Saudi Arabia’s by 2020. This has now been brought forward to 2015.

With environmentalists in Europe now gearing up to persuade the E.U. to turn the screws even tighter for 2025, perhaps it’s about time for the car manufacturers to finally pluck up some courage and say enough is enough.

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One Response to Flywheels Could Be Cheap Way To Slash Fuel Use In Cars

  1. Jean Y Noel January 2, 2015 at 10:46 pm #

    As an engineer, I have worked for automobile companies, and in the 80’s I have made my own tests on battery Charging with home made flywheel integrated to the rear axles of an old wreck where the flywheel kept spining full speed while being disengaged from traction Wheels motion when the car getting slower speed and also when immobile at a street stop, etc, etc, if I remember, on a 100 km distance on a usual driving stop and go, we were able to charge a lead acid battery about up to 50% charge +.

    would be interesting to test these again with to-days electronic and new méchanical device.


    Jean y Noel
    Bromont, Qc

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