Internal combustion engine hybridized

For road transport, fuel cells are the most efficient conversion devices for using hydrogen. For the average drive cycle, which is dominated by a power demand that is only a fraction of the maximum available power, hybrid fuel cell systems offer a clear advantage over internal combustion engines, hybridized or not, when energy use, CO2 emissions and non-greenhouse pollutants are considered. 

Transportation accounts for about one-fourth of the primary energy consumption in the United States. And unlike other sectors of the economy that can easily switch to cleaner natural gas or electricity, automobiles, trucks, nonroad vehicles, and buses are powered by internal-combustion engines burning petroleum products that produce carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons. Efforts are under way to accelerate the introduction of electric, fuel-cell, and hybrid (electric and fuel) vehicles to replace sonic of these vehicles in both the retail marketplace and in commercial, government, public transit, and private fleets. These vehicles dramatically reduce harmful pollutants and reduce carbon dioxide emissions by as much as 50 percent or more compared to gasoline-powered vehicles. 

Some of these began their work with electric cars. In Germany Ferdinand Porsche, built his first car, the Lohner Electric Chaise, in 1898 at the age of 23. The Lohner-Porsche was a first front-wheel drive car with four-wheel brakes and an automatic transmission. It used one electric motor in each of the four wheel hubs similar to today s hybrid cars, which have both gas and electric power. Porsche s second car was a hybrid, with an internal-combustion engine driving a generator to power the electric motors in the wheel hubs. On battery power alone, the car could travel 38 miles. 

Hybrid and clean diesel vehicles may cost more than current internal combustion engine vehicles. But, their greater fuel efficiency means that they may make up that extra up-front cost over the lifetime of the vehicle. This means that hybrids and diesels may have roughly the same annual operating costs as current internal combustion engine vehicles. 

Hickson, A., Phillips A. and Morales G. (2007). Public perception related to a hydrogen hybrid internal combustion engine transit bus demonstration and hydrogen fuel. Energy Policy, 35 (4), 2249-2255. 

Still, the efficiency of hydrogen fuel-cell vehicles is about twice that of current internal combustion engines on the highway, and about three times as high in urban traffic (and between 1-1.5 times more than hybrid electric vehicles (IEA, 2005)). A clear advantage of fuel cells is that at part loads, fuel-cell drives have a higher... 

In the series hybrid vehicle a ZEBRA battery would complement the internal combustion engine. This combination could offer pollution-free motoring within cities, with the more powerful but dirty petrol/diesel motive power used for longer journeys. In the 100 kW h to 10 MW h energy range the batteries would be suited to load-levelling. The ZEBRA battery is now being mass-produced (MES-DEA, Stabio, Italy). 

Figure 8. Prototype of a H2 burning internal combustion engine/electric motor hybrid. On the lower left is the H2 generator. On the lower right is the mechanical metering pump and electric motor. The upper right is the 3 kW engine, upper left is a standard automotive battery that can be charged by an alternator.

A major effort continues around the world to develop high energy, long cycle life rechargeable batteries for EV applications. Not only nonaqueous batteries, but many aqueous battery and fuel cell ideas are in development, often in the form of hybrid EV concepts, i.e., in conjunction with reduced size internal combustion engines. 

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