Wednesday, January 23, 2008

What is the Best Way to Power Our Cars? Part 3

For the last blog on the topic of alternative fuels in cars, I am going to focus on Electric Powered Vehicles (EVs)

What are they? They are vehicles that are powered by an electric motor. The electric motor is connected to a controller. And that controller is connected to a battery source in the car.

How does it work? Electric cars can use AC or DC electric motors. Without getting into too much electricity jargon, AC stands for alternating current and DC stands for direct current. AC motors are similar to a gasoline engine in that it requires a transition to operate. A DC motor, however, is designed so that you can have continuous acceleration. Both types of engines have their benefits and actually in the case of AC powered cars, a DC components is needed its operation.

These motors can be finely controlled and provide high torque from rest, unlike ICEV, and do not need gears to match power curves. This removes the need for gearboxes and torque converters. Internal combustion engines can weight almost 1000 pounds; where as, an EV motor can weight 75-100 lbs. EVs require a lot of batteries to power their motors, but they can be placed strategically around the base of the car for added stability (rather then a front heavy car).

Speaking of batteries, that needs to be discussed. The batteries are what makes or breaks an Electric Vehicle. And right now it is what is holding back the industry. There are a few important things that these batteries need to accomplish:

First, to give these cars a long range (50-300 miles) these batteries need to be able to hold a lot of charge. Next, to charge quickly (3-6 hours at night). Also, they need to last a long time (5-10 years).

These types of needs are specific to our perception of how any car should preform. We are used driving 200 miles before having to stop for 10 minutes to fill up on gas. And no one wants to have to shell out 2 grand on new parts every 2 years.

What are the benefits? These cars are a lot simpler than ICEV. There are a less parts in an EV, so that means a lot less money for repairs and replacements. When GM EV1s were brought in for repairs there was very little work that needed to be done. Air in the tires, maybe an aliment check, then you were on your way.

In addition, they release almost no air pollutants at the place they are operated. This would be a HUGE improvement to mobile pollution source reduction, one of the most difficult types of pollution to control.

As we talked about in the last section, hybrids use electric energy to get up to crusing speed so that the gas engine can work most efficiency. Electric motors often achieve 90% energy conversion efficiency over the FULL range of speeds and power output. Combine this with regenerative braking and you are really using your energy to the fullest.

Another advantage is that electric vehicles typically have less vibration and noise pollution than a ICEV, whether it is at rest or in motion.

Are EVs the answer? The answer in my opinion is 100% yes. Unfortunately, right now there are not that many available.

Monday, January 7, 2008

What is the Best Way to Power Our Cars? Part 2

For the second part of this discussion I want to talk about Hybrid Vehicles.

What is it? A hybrid automobile is any vehicle that combines two or more sources of power that can directly or indirectly provide propulsion power. You have heard of the Prius storming the nation and Toyota’s record U.S. sales. Are these hybrids the answer to all our problems?

How does it work? One popular type of hybrid is a parallel hybrid. This has a fuel tank that supplies gasoline to the engine and a set of batteries that supplies power to the electric motor. Both the engine and the electric motor can turn the transmission at the same time, and the transmission then turns the wheels.

The benefit to this system is that because the electric engine can assist in propulsion you can design a smaller gasoline for the vehicles. Smaller engines decrease the weight of the vehicle and use less cylinders (less gas). In addition, the electric power can be used exclusively until the vehicle has reached a cruising speed (15-40mph), at which time the gas engine can turn on and operate at its most efficient speeds.

The next advantage of parallel hybrids requires a quick and painless physics lesson. This is that “Energy can neither be created nor destroyed.” Whenever you step on the brake pedal in your car, you are removing energy from the car. The brakes of your car remove this energy and dissipate it in the form of heat. A hybrid car can capture some of this lost energy and store it in the battery to use later. This "regenerative braking” also will increase the life of your break pads.

One of the biggest ways to reduce emissions is to eliminate idling. When a hybrid comes to a stop at a light or in traffic, the gas engine shuts down. A hybrid car does not need to rely on the gasoline engine because it uses the electric motor to power the car from stopped to cruising speeds. So the hybrid car will turn off the gasoline engine, when the vehicle is stopped at a red light, which saves gas and reduces dreaded idling emissions.

Is this the answer? Yes and No. Hybrids are able to reduce tailpipe emissions and to improve mileage, but until recently even with increasing gas prices and new innovations in battery technology, hybrid cars and buses were not cost effective. It is inevitable, however, that with advances in technology the prices for these cars, trucks, and buses will be competitive with standard ICEV (internal combustion engine vehicles). Making them the obvious choice over standard ICEV. But maybe there is alternative?

Some hybrids require plugging in to recharge electric power. While some may avoid this, citing higher electric bills, plug in hybrids can achieve 150 mpg for their first 50 miles. Regular hybrids rely on the gas engine for the first part of a trip because the batteries need to be recharged by the alternator and the “regenerative breaking.” This means the gas engine would not shut off – when the car stops at a light and would kick on before the car reached cruising speeds – until the batteries have been charged.

My mother purchased a Ford Escape hybrid two years ago. It is an SUV and she was excited about having a more efficient large car. She didn’t do it for the money; she did it for the environment. The hybrid model cost about 7,000 more than the non-hybrid, she figures she’s not going to make that back, even with oil now at $100 a barrel.

· Escape FWD 4-cyl. - $19,995

· Escape AWD 4-cyl. - $23,235

· Escape AWD 6-cyl. - $27,145

· Escape Hybrid FWD - $26,970

· Escape Hybrid AWD - $28,595

Although this SUV is rated at 36 mpg City/ 25 mpg Highway, she has a computer on the dash that says she averages 27.8 mpg. This is despite that fact we live just outside of Washington, D.C., where she works.


Extra Reading and Sources:

Ford Escape "How Stuff Works"

Hybrid Cars "How Stuff Works"

Hybrid Vehicles Wikipedia

Thursday, January 3, 2008

What is the Best Way to Power Our Cars? Part 1

I want to break down this topic and talk about the pros and cons to alternative fuels in cars.

First lets analyze E-85 biofuel.

What is it? E-85 is a mixture of 85% ethanol and the rest gasoline. E-85 ethanol is used in engines modified to accept higher concentrations of ethanol. The gasoline ensures that the engine starts in cold weather, because straight alcohol won't.

So whats the purpose? In an attempt to decrease our dependence on foreign oil, the government, oil companies and car companies are investing in biofuels because the ethanol in the fuel can be produced from corn (a renewable source). There are some claims that E-85 burns cleaner, however, this fact is under debate.

Is this the answer? While the idea is seems noble, it is very short sighted and is not the end solution to our problems.

Let me explain why:

In 2005, the republican controlled congress passed The Energy Policy Act of 2005. This was in the writers words, "an attempt to combat growing energy problems provide tax incentives and loan guarantees for energy production of various type." This bill had many shortcomings, one of which was that it required that any federal vehicle that could operate on alternative fuels be operated on these fuels exclusively.

What you may be wondering is: why weren't they running on these fuels before? Well a recent GM study found that roughly 70 percent of its flex-fuel vehicle owners didn't know they could use E85, and fewer than 10 percent did so. The government at this time was only operating their own flex-fuel vehicles 51% of the time (the majority).

Well now this is good, the feds are going to use E-85 more and our dependence on oil will drop. Not quite. What this bill did is double the governments needs for E-85, creating a storage, limiting public availability and increasing its price. Currently, there are only around 800 public E-85 stations in the US and 1 in Canada. Bummer.

So why are car companies building E-85 vehicles anyway? Because as an incentive to develop alternative fuel cars, fuel economies for E-85 cars are multiplied by a factor. For example, a 15 MPG duel-fuel E-85 capable vehicle is rated as a 40 MPG under U.S. standards.

So even when it is estimated <1%>used in E-85 capable vehicles is actually E-85. By producing E-85 cars car companies are able to inflate their average fuel economy for all their vehicles.


Check out a few of my sources if you would like to learn about E-85 in more depth.

Article by
Wikipedia E-85

to be continued...

Wednesday, January 2, 2008

DC Green

Welcome to DC Green, where I plan to discuss pressing Environmental issues and ways to be more "Green."

In the last 2 years, I have been studying politics and researching green topics. I have found that the public is generally uninformed in both respects. While you can watch the news: it's biased; while you can find website articles: it is easy to get distacted and know which sites are based on real facts. I want to share some crediable facts and ideas that I have found and create a discussion on these green topics.

Thank you and enjoy.