Hybrids - What's Wrong?
I'm not particularly satisfied with the current hybrids out on the street such as the Toyota Prius, the Honda Insight, Civic hybrid, and those hybrid SUVs. Sure, they get good gas mileage, and some are all cute, but they have some problems. Now, I love sports cars; so let’s start there. How about a hybrid sports car? Ah, now here is a problem. Take the Toyota system; it uses a battery/electric motor in combination with a small efficient gasoline engine. When you need full power, both power-plants are used. Sounds good so far. One of those is the electric motor powered by a battery. The batteries charge, however, will eventually drain if the car is left under wide-open throttle for an extended period, and now you’re left with just the gasoline engine. Under track conditions, hybrids don’t work. The batteries will run out of charge, and then you’re left with one gasoline engine, but now it has to tug around a set of heavy batteries and a now useless heavy electric motor. That doesn’t sound like fun at all! Hold on! – I need to come into the pits and idle my car for 20 minutes while the batteries recharge so I can have full power again; for a little while. Then there’s the weight, which as we know is not good for handling or acceleration. At least the batteries are usually placed low in the chassis.
One other problem is the batteries themselves. We’ve all experienced rechargeable batteries degrade over time. When they are new they last a long time, and don’t take long to charge. Over time, their charge doesn’t last as long, they are not as powerful as when new, and they take longer to reach full charge. In addition the batteries tend to give off less power over a longer period as they age. For example, the light in your flashlight will stay dim longer with older batteries. With new batteries it stays bright and then more suddenly dies completely. Can you imagine that in a car? That would be awful! My car isn’t as fast as it used to be because it’s 2 years old!
For around town, hybrids do make sense since the two power-plants can be operated where they are most efficient, and regenerative braking can be used. At first glance, it seems this wouldn’t work since whenever you convert energy from one form to another, you lose some energy. With hybrids, you’re converting chemical to mechanical (gasoline to crank power), back to chemical (generator/motor charging the batteries), and then back to mechanical again (electric motor). It does, however, actually work; if you drive like granny does.
The Honda system is similar to Toyotas except the electric motor only comes on when more power is needed (Integrated Motor Assist). Still, you have the same problem, the batteries run out of charge and you’re left with just one engine instead of two. The 2006 Civic Hybrid’s performance is a plain disaster. 0-62MPH in 14 seconds. Fourteen seconds! That’s when both power plants are working; can you imagine what it is when the batteries no longer have charge? That’s borderline dangerous.
Then there are the SUVs – ugh. Most of the current SUVs take a normally powered full size gasoline engine, and then add on a hybrid system with batteries, an electric motor and regenerative braking to improve fuel economy and increase power output (at least for a little while). It works. They do get better fuel economy and they can quote higher horsepower numbers. Let’s not forget the weight though. The RX330 weighs in at 4,065lbs, whereas the RX400H comes in at 4,365lbs, an additional 300lbs. At those heavy weight numbers though, does it really matter? In addition, who takes his or her luxury SUV to the track anyway, and whoever has seen anyone with an RX330 towing anything. So – OK, for lame, heavy, don’t-make any-sense SUVs, it works. There I said it. In addition, in some states you can drive your heavy weight SUV in the HOV lane (high occupancy vehicle) with only one person in the car because, after all, it’s a hybrid, and I guess they are HOV vehicles since they weigh so much.
So – what to do with real vehicles like sports cars and sports sedans? On a gasoline engine, about 30-40% of the gasoline is converted to mechanical, haul your butt power. The other 60-70% of the gasoline is converted to heat, some which is absorbed by the cooling system and dissipated by the radiator, and some just radiated off the hot parts such as the exhaust manifold, and head (or heads for you boxer and ‘V’ engine guys). I find that an amazing amount of energy that is just wasted! One idea is to use this energy to boil water, and create high-pressure steam to drive a steam engine. Choo Choo! BMW has recently introduced a ‘TurboSteamer’ concept that is this very idea. It uses a steam engine to add power to the crank. Except for the added weight, this seems promising. Hurray! While cruising down the highway, the exhaust gas temperature on most gasoline engines sits around 1100 degrees F. That’s hot! Go wide-open throttle on a turbo engine, and you get up to1500-1600 degrees F. Diesel engines also see similar exhaust gas temperatures. There must be a good way to use this excess heat. Using the energy to drive a steam engine is a good one. Perhaps another is to drive a Sterling engine, or use some sort of thermocouple to create electric power. There’s a lot of energy there, but finding a way to use that energy is proving difficult. At least we’re not carrying around a load of heavy batteries and a heavy electric motor. Perhaps there is hope for hybrids, but for right now, hybrids are so wrong.