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by Jez Spinks

The rotary engine made famous by sports cars such as the Mazda RX-7 is the inspiration for a potential new portable electric generator.

Mazda is developing a Mazda 2 electric car that uses a compact, 330cc 22kW single-rotor engine as a range extender to recharge the battery pack and double the distance it can cover.

The Japanese company, however, says believes it could make the price of its electric cars more appealing to buyers if the rotary system could also have a secondary purpose as an electric generator.

“To make the [electric car] affordable we need to include value,” Mazda powertrain development manager Takashi Suzuki told CarAdvice in Japan. “If the system can be used as an electric generator, the value can be included.

“We couldn’t find a compact system producing 15kW and that’s why we believe there is a market for such an electric generator.”

Mazda rotary image

Suzuki-san said there were multiple uses for such generators.

“A convenience store is one example [of a buyer] – normally it would have a back-up generator, about 15-20kW. [Typically they] need space and instead of a huge [generator] there can be a small one.

“One home needs about 5kW [from a generator], and it could also be used for camping.”

Honda is one car maker that uses more conventional combustion engines for a range of portable generators (below), though Mazda points out they can weigh hundreds of kilos.

Honda generator

It says there are no true mobile generators that provide as much power as what the rotary is capable of.

The range extender assembly, also comprising a nine-litre fuel tank, is compact enough to fit in a small to medium-sized suitcase.

The future of Mazda’s ‘Wankel’ rotary has been the subject of much speculation in recent years, with the topic becoming more relevant since the company’s only rotary-powered car, the RX-8 sports car, was discontinued in 2012.

Mazda executives, including its global boss Masamichi Kogai, are adamant the company has not given up on developing a new-generation rotary car, though such a model seems to be years away.

Mazda engineers admit they’re still working on overcoming issues related to the distinctive engine – such as a shortage of low-end torque and high fuel consumption.

Rotaries – loved by enthusiasts for their smoothness and fast-spinning nature – have been part of Mazda’s engineering DNA since the 1967 Mazda Cosmo.

  • horsie

    These generators will become really popular around bankstown

    • Iggy

      they could be used to run the welders that stitch together the two halves of the C63s.

  • Doctor

    Sounds interesting…

  • Phil

    Good on Mazda for postulating other uses for the rotary, but portable generators? They might be small, but can they compete on fuel efficiency with diesel? 25kw class micro turbine generators on the market now have a footprint less than a standard pallet, so I don’t see that being a problem in the convenience store scenario. And they’ll run on diesel or NG.

    • Let The Truth Be Told

      Diesel engines will always be much more efficient than a rotary and more reliable long term, they can even run them on bio oils and often methane, sure the rotary would be smaller, but not be a lot.

      • Sydlocal

        Rotaries can also be run on methane without major modifications.

    • Sydlocal

      Rotaries can also run on many different types of alternative fuels with little modification. However not as many as a gas turbine of course.
      You also mention the poor fuel efficiency of the rotary when compared to diesels yet immediately follow on suggesting a gas turbine as another alternative? A gas turbine would even make a rotary look like a diesel when it comes to fuel economy….

      • Phil

        True that turbines aren’t that fuel efficient, though cogent improves it. The issue for Mazda’s pipe dream at the domestic level is NG fuel cell generators, which are about the size of a dishwasher and in cogen to provide hot water, reach around 80 percent efficiency.

        • Lush Drop Tintara

          Too bad that BlueGen had had to go offshore. Penny Wong would not support them because they were not fully renewable… This beggers belief!

  • David Tyler

    From what I read above they are suggesting that an electric car would double as a generator. Does this mean that there would be a socket on the bumper to take power from the generator? I also have to ask what the voltage would be? I assume it would be 110/220 and the car would have an inverter to create 12v for the batteries. That then leads to the next question. If the generator is 110/120 what voltage is the car driving motor and what voltage are the batteries? Questions questions, questions……

  • Scout392

    RACQ NRMA RACV will buy these, to jump start Nissan Leafs and all the new EV comming.