Hybrid Vehicle - Is Here To Stay

The Revolution of the Auto Industry

What is a hybrid vehicle?

A hybrid vehicle (HV) is one that uses two or more power sources. In cars, it means vehicles that use both a traditional engine powered by gasoline, and an electric motor powered by a battery. The battery is continuously recharged by the gas engine. Conventional vehicle is powered by only one gasoline engine run by fossil fuel. In comparison, hybrid vehicle uses two or more motor/engines. 

This diagram explains best: A  Hybrid Vehicle is a vehicle with a gasoline motor and an electric motor: expcars.com

The hybrid car is an example of 'green vehicle', designed to be fuel efficient, reducing cabon dioxide emissions thus leaving a smaller carbon footprint, to help in mitigating climate change.
Current hybrid electric cars (HEV) are mostly gas-electric hybrids, i.e. powered by
both conventional gasoline and electric engines (Diagram below):

Hybrid Electric Car with its gasoline and electric motor engine: auto.701panduan.com

The gasoline engine in a HEV is smaller, less powerful, but more efficient than that of a normal car. Under normal circumstances, the gasoline motor drives the car and provide electric power that is stored in a battery.  The battery then uses its stored energy to run the car at low speeds. Under demanding conditions that require high power: uphill drive or accelerating from rest, the electric motor is used. Some HEV, like the Toyota Prius, even shut down the gasoline engine when electric motor operation alone is sufficient, such as coasting and braking.

Typical HV achieves greater fuel efficiency and lower emissions than conventional vehicle by:

1. relying on both the engine and the electric motors for peak power needs, resulting in a smaller engine sized more for average usage rather than peak power usage. A smaller engine can have less internal losses and lower weight,

2. recapturing significant amounts of energy during braking that are normally wasted as heat. The braking converts some kinetic energy into electrical energy,

3. having significant battery storage capacity to store and reuse recaptured energy, for example in stop-look-go traffic within city driving.

(Plug-in hybrid electric vehicle PHEV: keetsa.com)

In fact, hybrid vehicles are all around and not new to us. For example, most trains are diesel-electric hybrids. Cities like Seattle have diesel-electric buses  that draw electric power from overhead wires or run on diesel when they are away from the wires. Giant mining trucks are often diesel-electric hybrids. Submarines may be nuclear-electric or diesel-electric hybrids.

While HV are far superior than conventional cars in terms of fuel economy, they are steeply costlier than their conventional counterparts. This makes fuel savings objective unattractive to the buyers. The last decade has witnessed rapid technological advancements in hybrid vehicles, thereby improving their efficiency. In addition, the ever-rising oil prices are also slowly gathering mindset favoring the fuel-efficient and eco-friendly hybrid car.

The three most popular hybrid vehicles from Japan: Honda Civic, Honda Insight and Toyota Prius, are capable of emissions of  4.1, 3.5, and 3.5 metric tons. Hybrid vehicle emissions today are capable of more than achieving the recommended target of 5.5 metric tons of carbon dioxide emissions for a typical passenger vehicle as set by the EPA (Environmental Protection Agency).

General Motors claims that its Chevy Volts is an electric car as it is always powered by the electric motors, and gasoline is used only to generate electricity. But critics claim that Volt is a hybrid, not an electric car, as it still resorts to gasoline powered engine. A hybrid electric car or PHEV, needs to be plugged into a power source to be recharged.

Hybrid      Conventional       Vehicle         Vehicle

With the incorporation of electric motors, and other subsidiary eco features, hybrid vehicles can reduce smog-forming pollutants by up to 90% and carbon dioxide emissions by 50%. Volkswagen has unveiled a new car, to go into full production for release in 2012, that can cover 100 km on less than a liter of petrol, making it the most fuel efficient hybrid in the world, emitting just 24 g of carbon dioxide/km.

Plug-in hybrid electric vehicle, (PHEV) Citroen C1 recharging on London street

The Leaf from Nissan which runs completely on stored electric power ( PHEV ), is capable of running for about 160 km between charges. Pure electric mode means it has no carbon emissions up till that point. That could meet the needs of the general public as survey indicates that 95% of drivers travel fewer than 160 km a day.

With the advancements in technology we shall one day produce electric trucks with a maximum loading capacity of 10 metric tons. But then we shall need a 10-ton battery to power it and that battery load would defeat the purpose of a truck.

Today, the HV batteries are one of the two types:
(1) nickel metal hydride, or (2) lithium ion.

Lithium-ion batteries are preferred than the nickel-metal hydride batteries, which have been utilized in the hybrid market thus far. In addition to its smaller size and lighter weight, lithium-ion batteries have the highest energy density of any rechargeable batteries. They produce a voltage more than three times that of nickel-metal hydride thus capable of storing more electric energy. The batteries also produce higher output (boosting vehicle power), higher efficiency (avoiding wasteful use of electricity), and provides excellent durability.

The lead-based or nickel cadmium batteries currently used in conventional cars are highly toxic and have been shown to cause teratogenic effects.

Despite many advantages, the sales of HV are definitely far from encouraging, mainly due to the steep price tags of HV. This high HV cost is going to be further aggravated by the depleting global supply of rare earth elements( REE ).

Rare earth elements are used in devices like smart-phones, flat screens, hybrid car batteries, magnets for all engines/motors, MP3 players and military equipment. Rare earth oxides, clockwise from top center: praseodymium, cerium, lanthanum, neodymium, samarium and gadolinium Photo: usda.gov

In view of concerns of carbon dioxide emissions and availability of oil reserves, the race to develop electric cars and other fuel-efficient vehicles has been placed as urgent priority.
The US-Obama administration set new rules to raise the average fuel economy, which in effect, is equivalent to increasing the number of HV cars on the road. In 2009, he announced programs directing $2.4 billion to electric vehicle. Obama’s New Energy For America program calls for deployment of one million plug-in hybrid vehicles by 2015.

According to market research for 2010, global sales of Hybrid Electric cars are estimated at 940.3 thousand units and are expected to cross the 1 million unit mark in 2011. According to industry statistics, less than 8,700 hybrid electric vehicles were sold in South Korea, accounting for less than 0.56% of its overall auto market. Even with the acquisition and registration taxes being exempted for hybrid cars, with these less-than-impressive figures, the country's first hybrid electric cars may have to be discontinued within the year.

China, in which per capita car penetration is just 1/20 of the US, overtook the United States in 2009 to become the world's largest auto market. Latest data for 2010 show year over year growth of 64%; with anticipated car sales surge in many more years to come. China plans to invest about USD15 billions in the next 3 years to boost the development of new energy vehicles, including electric vehicles, hybrid electric vehicles and fuel cell vehicles. It is anticipated to put 500,000 new energy vehicles on the road by 2015 and 5 million by 2020. At this initial stage, programs have been launched in five cities to provide subsidies of around USD 7000 for each purchase. However, to-date, HV car sales have been dismally disappointing, hampered by the steep price tags and limited range of batteries. Take for example, BYD sold less than 500 plug-in hybrids in 2009.

Elsewhere, HV continues to gain increasing popularity. In 2010, hybrid electric vehicles took up about 2.4% (or 275,000 units) of the US market despite falling auto sales. In Japan, the sales of Toyota's hybrid electric car Prius hit an all-time high of 315,000 units, which is close to 10% of the 3.23 million automobiles sold in that country last year.

Despite the global attention given to hybrids, all signs are pointing to a possible internal combustion comeback, with the new engine efficiency improving in leaps and bounds.  Diesel fuel is denser than gasoline. It produces more energy and emit about 20% - 30% less carbon dioxide. The disadvantage is its high level of sulphur that causes air pollution and produces a repelling smell. However, refined diesel would help solve this problem. There is a great possibility that diesel and natural gas will become the norm for large, long-distance trucks and other commercial cars.  So that leads us to an up-and-coming "green" internal-combustion hybrid car to be run by natural gas and biomass-derived fuel.