• Feb 11th 2010 at 11:56AM
  • 11
Porsche 911 GT3 R Hybrid – Click above for high-res image gallery

The hybrid drive system being used by Porsche in its new 911 GT3 R that we recently learned about isn't what you find in your average Prius or Fusion. Instead of a battery for energy storage, the 911 will use an electro-mechanical flywheel. The system being used was actually developed by the Williams Formula One team and its Williams Hybrid Power subsidiary.

The system is comprised of an electrically driven flywheel and a motor/generator on the gearbox. During braking, the gearbox-mounted generator drives the flywheel to spin it up to 40,000 rpm. When needed for extra acceleration, the flywheel drives its integrated motor/generator to spin provide power back to the unit on the gearbox.

In the case of the 911, a pair motor generators are actually on the front wheels instead of the single unit on the gearbox as it was on the Williams F1 car last year. This provides more regenerative braking capability as well as all wheel drive.

The flywheel itself is made of a composite material that is infused with magnetic particles when it is being molded. This actually acts as the permanent magnet for the motor, helping to keep the overall weight down. The result is a very efficient system with less mass than a battery system and the ability to absorb energy more rapidly than a battery similar to an ultracapaitor. Like ultracapacitors, the downside for automotive applications is limited energy storage capacity.

As a result, electric driving in the 911 GT3 R is limited, meaning that this really behaves more like a mild hybrid system than a strong hybrid. However, the power output is closer to what is available from most strong hybrids. Williams Hybrid Power is working with a number of automakers on implementing its flywheel system although only Porsche has been publicly identified. The press release and a video explaining the system are after the jump.

[Source: Williams Hybrid Power]




Oxford, UK, February 11, 2010. Williams Hybrid Power Limited is pleased to confirm that the energy storage system as part of the new Porsche 911 GT3 R Hybrid, which was announced today by Dr. Ing. h.c. F. Porsche AG, Stuttgart, has been developed and supplied by Williams Hybrid Power. The 911 GT3 R Hybrid with innovative hybrid drive will make its debut at the Geneva Motor Show. Further details from Porsche follow in the attached press release.

The energy storage system was originally developed for use in Formula One by the AT&T Williams team but Williams Hybrid Power is now focused on applications in road vehicles. The technology will also be developed for larger, infrastructure applications by Williams F1 at its new research facility in the Qatar Science and Technology Park.

Ian Foley, Managing Director of Williams Hybrid Power said, "We are delighted to see our technology being adopted by one of the world's leading engineering companies and most prestigious automotive manufacturers in one of their racing cars. Partnering with Porsche on this project has been a very positive experience and we are grateful to them for choosing to work with us."

Alex Burns, Chairman of Williams Hybrid Power and Chief Operating Officer of Williams F1 said, "This is a milestone for both Williams Hybrid Power and Williams F1. Together we have worked to bring this technology forward to the point where it can be tested in a racing car and deployed in a road car. We hope that this will be just the start of the evolution of hybrid systems developed for Formula One moving across to applications where they can contribute to cleaner and more powerful vehicles."

I'm reporting this comment as:

Reported comments and users are reviewed by Autoblog staff 24 hours a day, seven days a week to determine whether they violate Community Guideline. Accounts are penalized for Community Guidelines violations and serious or repeated violations can lead to account termination.

    • 1 Second Ago
      • 5 Years Ago
      ISTR that way back in the '80s in San Francisco there were MUNI buses that used a flywheel for power. They were accelerated at the depot and then could drive for hours up and down the hills of SF on that power. Always wondered why that system was never employed for other vehicles...
      • 5 Years Ago
      Wired says the system has two 60 kW electric motors on the front axle. That's a lot of power, but I still wonder what the benefit of the system is over batteries; the energy storage for 2 minutes of maximum power is just 4 kWh.

      It would be cool if you could plug it in at home to spin up the flywheel to 40,000 RPM for the first burnout of the day.
        • 5 Years Ago
        The advantages are mainly that it regens a much higher percentage of the braking energy than batteries will and can last for probably 100's of thousands if not a million cycles (they really compete directly with supercaps) and it has much higher power density than most batteries will ever have for greater acceleration.

        But also like supercaps, they don't have enough energy density so as you pointed out, you could get a lot more driving time from a few kilograms of batteries.

        But the point of this type of flywheel and supercaps, is just to maximize the energy savings from regen braking and put out as much power as possible for a few seconds to get some extra oomph when you hit the "gas" pedal.
      • 5 Years Ago
      Has anyone ever seen an example of both approaches in 1 vehicle, meaning a flywheel acting as a supercap for regenerative braking and batteries for cruising?
      • 5 Years Ago
      Would anyone care to explain (or provide a link for additional reading) this "electric flywheel" storage system? I'm having problems grasping the concept of storing the energy in a flywheel.
        • 5 Years Ago
        Yeah, I noticed after I posted that it used electric motors, but since there is STILL NO EDIT BUTTON... autoblog...

        But the principle is the same. Just swap clutches and shafts for electric motors and wires.
        • 5 Years Ago
        all i know is this: I don't want one in the passenger seat when a ceramic bearing goes out.

        but this sounds pretty cool: power from the wheel motors (acting as generators get the magnetic flywheel spinning at 40,000+rpms...a little faster with each braking zone...losing only a little to friction internally...

        then that can be converted directly back to electricity and pushed to those same motors.

        nice trick, and it can completely recharge itself in 15 minutes or so...let alone that it could be preloaded before you even hit the track...or re-energized during a pit stop.
        • 5 Years Ago
        Kinetic energy is 1/2 MV^2 so you can store more energy using a higher rotational speed. Modern composites have advanced enough to make composite flywheels a realistic option. This one is especially clever as it has magentised composites so all the power addition and take off can be done electronically without a physical connection so it should last much better.

        It will be an interesting battle with supercaps, flywheels and batteries.

        Batteries / supercaps could be fitted under the floor of a vehicle whereas a flywheel is a more difficult shape to package
        • 5 Years Ago
        It's basically just a big heavy wheel which can store rotational momentum. So, when you are slowing down, you can clutch in the flywheel to spin it up, then when you stop braking, you clutch out the flywheel. The flywheel will keep spinning for a long time, and when you need a little boost of power, you can clutch the flywheel back in and let it drive the wheels in addition to the engine. But, unlike an electric motor, you can only run the flywheel until it equalizes speed with the wheels.
        • 5 Years Ago
        you're describing a mechanical flywheel system. While the energy storage is the same as an electro-mechanical system, the means to get the energy in/out is different. In the E-M system, there's a motor-generator connected to the drive wheels (as described in the article) and another connected to the flywheel. Energy is generated by the drive wheel motor-generator during deceleration and used by the flywheel motor-generator to accelerate the flywheel. Then when that energy is wanted by the driver and he/she presses the button, the flywheel motor-generator decelerates the flywheel turning that energy back into electricity to be used by the drive wheel motor-generator... Of course there are losses at each stage of the energy conversion, but no where near the infinite amount from the friction brakes. :-)
        • 5 Years Ago
        My impression was that the flywheel is electrically driven in this case. I.e. instead of using a clutch, it has an electric motor/generator attached to it. When you brake, you use a regenerative braking system to capture electricity which is used to spin up the flywheel. The flywheel then keeps spinning for a long time like Joe said. Later, when you need a boost, you use the rotational kinetic energy stored inside the flywheel to spin the generator and thereby produce electricity which can be fed back into an electric motor attached to the wheels. In this kind of a system there is no issue (I think) if the flywheel is actually spinning more slowly than the wheels. As long as it has some rotational kinetic energy, that energy is convertible to electricity and can be used to accelerate the car.
    Share This Photo X