Hybrid : a composite of mixed origin; So Hybrid means many things, and there are a wide range of 'Hybrids'.
Certainly it makes sound sense to go after the really 'free' energy, which is braking energy, and also easy waste energy, which is 'Traffic Light' / Gridlock energy.
So that points firstly to & Stop/Start or Stop/Go technology. A quite mild hybrid on the ICE/Battery Continuum. Next, you might like to nudge up the Electric portion: The battery, a bit, to better collect the regen braking, and the Motor, a bit, to give better acceleration, and drop the kg's of the main ICE. Less weight = less fuel.
Expansion beyond that point, becomes dependent on the range and usage.
Selinz, why is this comment on conserving fossil fuels surprising? What is the goal of conservation? Not to extend the availability of a finite commodity by a month or two out of two hundred years, surely. In point of fact, unless you stop using fossil fuels entirely, they cannot be conserved, only exhausted. Whether this happens in 2090 or 2525, what difference does it make? They _will_ run out and the people who need fuels at that time had better come up with a solution. Note well: they have to come up with a solution. We aren't responsible for solving their problems, and they wouldn't take the solution anyway. My comment on burning all of the gas I can is partially tongue-in-cheek, but not entirely. Let us conserve what can be meaningly conserved, and forget about conserving for the dubious sake of conserving. As for hybrids, I'm pleased that you are satisfied with yours. (For a fact, it's hard not to be pleased with a Honda or Toyota.) But what if someone wants to drive a Seville, and not a Honda? They at least have the option in the US, at a price, of course. Curiously, I saw a 1970 FJ Cruiser for the first time yesterday, as I happened to overtake it on an interstate, wondering what it was. The driver waved cheerfully at me in my FJ, and recognition struck. For the record, it gets 21 on the highway, maybe 18 in the limited city driving it gets. Hardly the industry's worse gas drinker: have you looked at what a Hummer drinks lately? Plus: I like it.
The assertion that "since we are running out of gas eventually, why bother trying to conserve" is surprising for me to see on a site that is presumably inhabited primarily by engineers. I drive a Honda Civic Hybrid. Now to be honest, the only reason that I bought it was because it looks like a regular civic (couldn't bring myself to drive a prius) and it lets me drive solo in the carpool lane (legally). Before this vehicle, I was perfectly happy with my Cadillac Seville which would average 23mpg. The Hybrid costed about $3K more than a comparably equipped Civic. And I got a $2500 tax break. I've put 140K miles on the car since December of 2006. 140K divided by 22mpg = 6363 gallons of gas. That means that in about 3.5 years, I've saved about $10K in gas cost. NOt to mention the enjoyment of passing jillions of vehicles while in the carpool lane. I'm guessing it saves me 20 minutes/day. So that means I've saved 210 hours of drive time since I've had the car. I average more than 75mph. The car can easily do over 100mph and I can out accelerate most SUV's and small cars.
I do recommend that people do the math...stick it in an excel spreadsheet. But it's important to have correct numbers.
FYI, I had a 1970 FJ cruiser when I was in AZ and loved it. But I rarely drove it to work. It was suited for offroad and that's how I used it. I believe the new FJ's actually get worse mileage than the old ones (one of the industry's worse gas guzzlers, particularly when you consider what it can carry and what it's capable of).
Let's try to get our facts straight.
Since this is EE Times, can't we just explain that the motor/generator, battery and transmission form a low pass filter that allows the ICE to remain at its optimal operating point much of the time. The designer can trade system cost (corner frequency of the filter) vs. fuel economy. Or from a mechanical engineering viewpoint, that the electric motor provides the low end torque, eliminating the need to oversize the ICE.
For those of you interested in problems to ponder, here are two. 1) Why do we ship stuff cross-country in tractor trailers? Why doesn't almost everything going more than 100 or 200 miles get placed on a freight train? Or does it already, and I am unaware of it? 2) How much energy is used by daytime driving lights in the US? The answer can be express in units of 1000 MW power plants if you like.
ROckstar, thank you kindly. I take your comment exactly as stated, as praise. I would like to point out that precisely because fossil fuels are a finite commodity, there is little point in extreme measures of conservation, because sooner or later, we surely will run out of the asset. What shall we do then? I'm not certain, but I doubt that wind power or solar energy will play much of a part.
On the other hand, "finite" doesn't mean "runs out next week". The US holds enormous coal resources. True, the coal is sulfur-laden, and even I would insist that before using a liquid version in consumer vehicles that the sulfur be removed. No one needs acid rain. At a price, of course. Ditto for US uranium reserves... it makes a mess digging it out (in places of low population) and it must be stored after use, but anyone not clear on the virtues of nuclear power can talk to the French. They seem to like it. (By the way, the waste product of a nuclear reactor is dangerous for what? 3000? 6000? years? How long is the waste from a fossil fuel plant, the ash, dangerous? When it is full of concentrated heavy metals: forever. Take your choice.)
By the way: fossil fuels are just the original solar power, aren't they? ;-)
To me, larger vehicles like monster SUVs are really the only place that a hybrid makes much sense. If you can take a vehicle from 12 mpg city (more realistic than the 15 stated) and turn that into 20mpg city, assuming a 200K vehicle life, 50% in city driving and $4.00/gallon gas, you save $13,000 over the life of the vehicle.
On the other hand, taking a 98hp 35mpg car and turning it into a 45mpg 134hp hybrid, saves you only $2,500, given the same assumptions (only twice that if you assume the same mpg boost comes on all 200K miles). Using a hybrid essentially as a means to increase horse power is not a "green" way to go. Much better would be to forgo the $10,000 extra power system and simply drive the 98hp 35 mpg car around.
Small vehicle hybrids don't make economic nor environmental sense. Large vehicle hybrids can help as a stop-gap until we really solve the fuel problem.
Bob, you are my hero. It's people like you who are willing to brave ridicule from tree huggers & the like and make a personal sacrifice by buying up extra gas every time you fill up, removing just a little bit more of the finite fossil fuel supply than others are willing to, causing the price to go up, making green energy that much less uncompetitive. Doing the right thing isn't always easy, but you're sticking to your guns, and that's an inspiration to us all!
Blog Doing Math in FPGAs Tom Burke 0 comments For a recent project, I explored doing "real" (that is, non-integer) math on a Spartan 3 FPGA. FPGAs, by their nature, do integer math. That is, there's no floating-point ...