Our CO2 Reduction Scenario
Opinions vary with regard to the levels at which average global temperature and CO2 concentration will need to be in the future. According to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), it is necessary to stabilize atmospheric CO2 at 450 parts per million or lower in order to keep average temperatures from rising more than 2 degrees Celsius on a global basis. Based on this, we have calculated that "well-to-wheel" CO2 emissions for new vehicles-including "well-to-tank" emissions, from primary energy extraction through fuel refinement and delivery to customers, in which automakers are not involved, along with fuel consumption during operation-need to be reduced by 90% in 2050 compared with levels in 2000.
To help achieve this 90% reduction, we see the need to further improve the fuel efficiency of internal combustion engines in the short term, and in the longer term, to bring about widespread use of electric and fuel-cell vehicles, making use of renewable energy sources to provide the power they need. We are bolstering our development of new technologies with this long-term scenario in mind. Specifically, we are concentrating our efforts on two pillars: Zero Emission, which involves widespread use of zero-emission vehicles in a holistic approach to promote a sustainable society, and PURE DRIVE, which reduces CO2 emissions by developing fuel-efficient internal combustion engine technologies and introducing them into the market.
Improve fuel efficiency
Nissan is engaged in a comprehensive program of technological development aimed at reducing energy loss in its engines, the three pillars of which are (1) burning fuel efficiently, (2) reducing air intake/exhaust resistance, and (3) reducing friction in the engine.
(1) Burning fuel efficiently
An engine's revolutions per minute vary depending on whether the vehicle is traveling fast or slow, and the optimal amount and compression ratio of air also differ. Nissan is developing technology to burn fuel more efficiently, including by controlling the airflow to the engine in accordance with the car's operating status.
(2) Reducing air intake/exhaust resistance
Energy is lost because of air and gas resistance in the engine when air is taken into the engine and when exhaust gas is expelled after burning. Nissan is developing technology to reduce this resistance.
(3) Reducing friction in the engine
An engine consists of various parts, and energy is lost through the friction that occurs when parts rub against each other. Nissan is developing technology to reduce such friction.
Hybrid vehicles/Plug-In Hybrid Vehicles
FUGA HYBRID
Hybrid vehicles are powered by a combination of a gasoline engine and electric motor. Their main advantage is superior environmental performance marked by low emissions of not only CO2 but also nitrogen oxides (NOx) and hydrocarbons (HC). In 2008, Nissan developed a parallel hybrid system in which a motor used for both propulsion and regeneration is connected directly to the engine and the transmission using two clutches. The system also incorporates a high-power lithium-ion battery. In November 2010, Nissan launched Huga Hybrid for a sales in Japanese market, adopting the system and achieving fuel economy of 19.0 km/L (10-15 mode).
We are also moving forward with research and development on plug-in hybrid vehicles that do not emit CO2 when operating in its electric-only range.
Electric vehicles (EVs)
Nissan LEAF
Powered by an electric motor and battery, EVs are clean vehicles that do not emit any CO2 or exhaust gas during operation. Nissan has been working to develop EVs in earnest since the 1960s, and has introduced and sold a number of these vehicles on the market. And in December 2010, Nissan launched Nissan LEAF, the company's first affordable, mass-marketed, 100% electric vehicle in Japan and the United States, and in 2012 will commence large-scale global sales of the vehicle.
Fuel cell electric vehicles (FCEVs)
The 2005 models of X-Trail FCEV (Japanese market)
Fuel cells derive electric energy directly from the reaction of hydrogen and oxygen, and their sole emission is water, making them an exceptionally efficient and clean power source.
Nissan's aim is to develop a practical FCEV with superior environmental and energy-saving performance while maintaining ease of handling as an automobile, by employing elements of the various technologies Nissan has cultivated over the years (lithium-ion batteries for electric vehicles, high voltage electric system technology, control technology for hybrid vehicles, high pressure gas storage technology for compressed natural gas vehicles, and more).
In 2005, Nissan achieved driving range and acceleration performance in the latest model X-Trail FCEV that was the equivalent of a similar gasoline vehicle. This X-Trail FCEV is equipped with a 70 MPa high-pressure hydrogen tank and a fuel cell stack developed in-house by Nissan. Since fiscal 2003, Nissan has been marketing FCEVs for lease on a limited basis, and is now making further improvements with the aim of launching next-generation FCEVs in the early 2010s in North America and Japan.
