On the Road to Renewable Transportation

The OECD estimates that replacing 10% of the country's motor fuels with bio-fuels would use one-third of all croplands.

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By Béla Lipták

The coming third industrial revolution will convert the global economy from exhaustible sources of energy to renewable ones. We process control professionals will play a major role in this transition. My new book on renewable energy process automation, Post-Oil Energy Technology: After the Age of Fossil Fuels, describes the new control systems we will use.

Here I will discuss just one aspect of this future: transportation. The following trends are observable:

  1. pressure on car manufacturers to improve their fuel economy;
  2. pressure on manufacturers to develop gasoline and diesel engines that use ethanol-gasoline mixtures and bio-diesel fuels;
  3. pressure on manufacturers to introduce multi-fuel vehicles;
  4. pressure on manufacturers to introduce regular and plug-in hybrid cars;
  5. development of electric cars using new high- density batteries;
  6. development of electric cars with hydrogen fuel cells; and
  7. development of hydrogen combustion engines in cars.

The car manufacturers have not decided yet if the future belongs to the all-electric car, the hydrogen fuel cell, the hydrogen-burning internal combustion engine or some multi-fuel vehicle. Each has its advantages and disadvantages. The efficiencies of the various engines presently in use are gasoline, 25%; diesel, 35%; hydrogen IC, 38%; hydrogen fuel- cell, 45% to 60%.

Bio-Fuels and Multi-Fuel Vehicles

By 2020 the EU wants to replace 10% of its transportation fuel with ethanol. In China the number is 15%. In the U.S., the Senate is proposing a bio-fuel production target of 36 billion gallons by 2022, of which 21 billion would come from corn-based ethanol. At the same time the Organisation for Economic Cooperation and Development (OECD) estimates that the replacement of 10% of America’s motor fuels with bio-fuels would require about one- third of all the cropland, which today is devoted to the production of cereals, oilseeds and sugar crops.

The three main American car manufacturers are planning to have half of their fleets run on E85, a blend of 85% ethanol and 15% gasoline or on bio-diesel fuels. Ethanol is corrosive, can not be distributed through gasoline pipelines, trucks, railcars or barges. While the government subsidized ethanol production and in 2005 mandated its use, it did nothing about its distribution. Hence, corn prices doubled (from $1.65/bushel to $3.37/bushel), the number of ethanol plants nearly doubled (from 81 to 129) while only 1,000 out of the 179,000 gasoline stations can pump it and while nearly 40,000 ethanol rail cars are on back- order.

Consequently, during the last 12 months, the price of ethanol collapsed, dropping from $3.60 to $1.80/gallon.

Hybrid Cars

The GM Chevrolet Volt hybrid-electric car is estimated to give 150 miles per gallon and be available by 2010. Honda has dropped the hybrid versions of Insight and Accord and, in addition to its hybrid Civic, is working on a completely new hybrid car. Toyota, after the success of the Prius, is planning to have a hybrid version of all its models by 2010.

Toyota’s Prius is available in a version that has been converted to hydrogen by Quantum Fuel Systems. Conversion kits are also available to convert the Prius and Ford’s Escape into a plug-in-hybrid, which it says will get up to 75 mpg, by the addition of extra batteries.

It has been suggested to use the stored electricity in the batteries of plug-in hybrid cars on the utility’s grid to reduce peak demand. The contract between the owner and the utility would contemplate that at night—when electricity is inexpensive—the owner would  charge the batteries, and during peak periods, if the car is not in use, it would be left plugged in, and the charge in the batteries would be available to the utility, always leaving enough power to start the gasoline engine, until recharged.

Electric Cars

Electric Vehicles (EVs) are no longer just glorified golf carts. Today at least ten electric car designs are in production, and more are on the way.

Energy independence and operating cost are the main advantages of replacing internal combustion (IC) engines with batteries—energy independence, because electricity is made mostly from American coal and operating cost, because the price of a gallon of gasoline can pay for the electric energy used to drive 100 miles. Another advantage of the electric car is that its fuel distribution infrastructure already exists, since only an electric plug is needed to refill the batteries.

The main disadvantage is cost, namely the purchase price of the electric car, which today is still around $100,000. Other disadvantages include limited driving range, long charging time, short battery life and small cargo space, which is limited by the weight and size of the batteries. Some high-voltage charger designs (Altair Nanotechnologies), claim to reduce the several hours normally required to 10 minutes. Other ideas include the design of “filling stations” that would replace the block of batteries with already charged ones. These electric filling stations could also offer multiple fuels.

During the last 25 years, the cost of batteries has been reduced by a factor of 12, and according to the California Air Resources Board, if lithium-ion packs were mass-produced, their unit costs would drop to $3,000 to $4,000.

In yet another experimental design variation (by Solar Electric of California), solar collectors are added to the roof of the car and use the electricity generated to recharge the batteries.

Fuel Cells vs. Batteries

Unless new batteries are discovered that can safely provide much higher energy densities, fuel cells will continue to outperform today’s heavy and large storage batteries. Today’s batteries are less expensive than fuel cells, but their energy density is insufficient, and their weight and size are both too high to provide the required driving range. The final outcome of the battery versus fuel cell race cannot be predicted yet, because there are substantial developments in both fields.

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