Widespread Use of Hybrids Could Save 50 Percent on Fuel

Fri July 11, 2008 - National Edition
CEG



New research shows that the construction equipment industry could reduce its carbon footprint by millions of tons a year and radically cut fuel consumption by a wholesale adoption of hybrid technology. That was the message of a recent speech given by Volvo Construction Equipment’s Arvid Rinaldo. The presentation, to a group of international business journalists in Sweden, said that continuing research into diesel-electric hybrids showed benefits in fuel reduction, CO2 emissions and performance significantly larger than previously stated.

“Hybrids are not a gimmick — construction equipment responds extremely well to the technology,” said Rinaldo. “We are facing the very real prospect of fuel savings up to 50 percent, significant performance increases and a reduction in CO2 emissions in the order of millions of tons a year, if adopted industry-wide.”

Volvo CE was the first company to officially launch a commercially available hybrid wheel loader when it unveiled its L220F hybrid in the United States, in March. Offering fuel reductions of 10 percent (depending on application) the L220F’s overwhelmingly positive reaction from customers and other stakeholders encouraged Volvo CE to redouble its development efforts into hybrid technology, according to the company.

Working in cooperation with Volvo Group companies Volvo Technology and Volvo Powertrain, Volvo CE will start deliveries of its L220F hybrid in late 2009. The heart of the hybrid system is an ISG — Integrated Starter Generator. Fitted between the Volvo D12 engine and the transmission, the ISG is coupled to a battery that has many times the power capacity of a normal lead acid battery. The ISG allows the diesel engine to be turned off when stationary — and then almost instantly restarted by rapidly spinning the engine up to optimum working speed using a burst of energy from the high power battery. As up to 40 percent of a wheel loader’s time can be spent with the engine idling, this will be a major benefit.

The ISG also can overcome diesel engines’ traditional problem of low torque at low engine speeds by automatically offering a massive electric torque ’boost’ — as the ISG’s electric motor offers torque of up to 700 Nm from standstill. Put in engine power terms — the ISG adds up to 67.5 hp (50 kW) of instant mechanical energy.

The combination of these two attributes of the ISG means that the diesel engine will remain off for long periods when it would otherwise be idling. The operator doesn’t need to over-rev the engine to get sufficient torque to work, as peak torque will be offered at low rpm or even when the engine is idling. This will make the machine feel much more powerful and responsive. The battery is then replenished automatically without reducing productivity, with the ISG acting as a dynamo/alternator.

“What we are looking at here is a true case of ’disruptive technology’,” concluded Rinaldo. “Our ongoing research shows that such are the benefits of hybrid systems that we could well see a paradigm shift in the powertrain of modern construction equipment.”

For more information, call 828/650-2000 or visit www.volvo.com.