Will Plug-In Hybrids Become the Standard?
Farmers are planting corn and soybeans like crazy, turning food crops into ethanol and biodiesel. Scientists are squeezing oil out of algae while others are trying to coax hydrogen into a fuel that is easy to produce and safe to use. Still other developers are touting the battery-operated electric car, and one company is building a car that runs on compressed air.
Which system will survive? Or will we have a mixture of E85’s, biodiesel, electric, air and hydrogen fueled vehicles cramming our highways and straining the fuel delivery system infrastructure? Eventually, according to the age-old theory that the fittest shall survive, one method of moving us from point “A” to point “B” will emerge, and some folks are betting on the plug-in hybrid.
Designing a battery that will store a lot of energy and handle power surges has been a real problem for automakers. The Lithium-Ion battery has shown it can do both, but engineers say rapid discharges can degrade the battery’s lifetime. One car company using Lithium-Ion batteries, Tesla Motors , has developed a high-performance, all electric roadster with a range of 200 miles or so. The price tag, around $90,000, give a take a few thousand, takes it out of the family car bracket.
Hybrid-electric vehicles combine a battery with an electric motor and a gasoline engine to propel the car. The engine, and energy regenerated during braking, keep the battery charged and the car moving.
Designing a practical plug-in hybrid is another story, and it’s all about the battery, or batteries. It takes more batteries for a plug-in, with substantially different capabilities, such as storing a lot of energy and providing quick acceleration, or discharge of energy when needed. In addition, these batteries need to be more compact, affordable and safe as they cycle through various uses.
Lithium-Ion batteries fill most of that bill, but their useful lifetime can be degraded by sudden sudden surges of power, and there still seems to be a lingering doubt as to their complete safety when overheated.
So how do we answer the need for quick power surges and large storage capacity? With capacitors, of course.
Actually, they’re called Ultracaps, the electrical equivalent of a shaken champagne bottle. The difference being they also recharge quickly, having 10 to 100 times the power density of typical batteries and only one-tenth the energy density.
In case you aren’t acquainted with capacitors, I’ll try to help. First of all, capacitors are used in every electronic circuit, in your computer, tv, radio, and cell phone to name a few.
How do they work? Take two separate strands of wire, and on the end of each, attach a flat piece of metal we’ll call a plate. In between these plates, place what is called a dielectric, or a material that will not pass electricity, and put all that into a material that holds it all together which is, in itself, a dielectric.
Now, hook one wire up to the positive side of a battery, the other to the negative side for just a second. A charge builds up on one plate only, and stays there until you put the two wires together, and the capacitor discharges in a flash. I wouldn’t try this with a huge power source, a 6 volt drycell should give you a small spark.
Increase the size and capacity of these capacitors and you have ultracaps, capable of providing an instant power thrust and literally recharging a second later. This, as they say, is a marriage made in heaven for plug-in hybrids.
A working example of this concept is the Extreme Hybrid which was rolled out at the Detroit auto show in January. The developer, AFS Trinity, is not an auto company. They took a Saturn vue hybrid and retrofitted the vehicle to achieve a 40 mile electric range before reverting to run efficiently on it’s gasoline engine like a normal hybrid. Gas mileage comes in at around 150 mpg.
The Extreme Hybrid site features several videos featuring the car. No, it isn’t ready for production yet, but the technology has been proven and this type of plug-in hybrid may become the standard for automotive transportation in the future.
You might say, but what about the gasoline? Will we still have to buy fossil fuels to run our small engines? Not likely, with the advances in biofuels, especially the promise of algae-derived fuels, the day may soon arrive when we won’t use gasoline at all.
What a concept.