The Distance Project

The Power of Hybrids

Posted on October 10th, 2007 by Zach.
Categories: Sustainability, Systems of the World.

The other night I was at dinner and found myself in discussion with someone unimpressed by the Hybrid car revolution. Fair point from the outside I suppose, but I thought it was worth a little bit of time here to show why hybrids matter.

When it comes to cars, one of the first thing people look at is gas mileage and on that front most of the Hybrids are pretty good, if not mind blowing - somewhere between 30 and 50 mpg depending on the size of the engine. This is better than the national average, but for a regular Civic driver or someone who drives a TDI from Volkswagen, it is not enough to pony up the extra bucks.

Fuel efficiency is a big deal obviously and I don’t want to devalue how important it is in the larger equation. Energy conservation is the single most important challenge facing the U.S. Vehicles are no different, and hybrid technology is addressing this as the technology matures. 

In terms of the impact of hybrid technology though, fuel efficiency is only part of the equation, and I would argue the smaller of the two. What really matters are the emissions.

In traditional cars and trucks a large majority of emissions are produced either when the vehicle is at idle, or moving at slow speeds. Stop-and-go traffic for example, is an emissions nightmare. So much so that cities see significant reduction of pollution when they use more timed traffic lights systems. By reducing the number of times cars have to stop for lights, the pollution levels are lower.

Because a hybrid vehicles operates on an electric motor during these critical times (0 -15 mph), the emissions are reduced by a large factor. The numbers are actually staggering: around 80% of the total emissions in a three mile drive are created during the first mile.

To put the impact of this into perspective next time you are stuck in bumper-to-bumper traffic that forces you to slow down around 10 - 15 miles an hour, take a look around you and imagine every one of the cars putting out zero emissions. In every major urban area these days, this is a daily occurrence at rush hour.

Idling my not seem like a big deal to the average person, but it is. According to a Washington State University Study, trucks and buses burn in the neighborhood of 840 million of gallons of diesel a year JUST IDLING! Combine that with the emissions quotient and the numbers for trucks are just plain scary.

Trucks at idle, cars in traffic, imagine if every one of those vehicles were producing zero emissions. Hybrid system are a critical answer to these issues, and that is why they matter now.

They matter for future innovation as well. Emerging technologies like plugin hybrid systems up the electric speeds from 0-15 mph to actual cruising speeds - spurts of 50+ mph. The systems are only going to get better.

Most importantly, hybrid systems separate the energy production from the motor. In current examples like the Prius, a gas engine charges batteries which then run an electric motor. At high speeds the combustion engine kicks in as well, but increasingly the electric motor takes the load with the gas engine used for producing electricity.

Future systems will fully divorce the engine from the motor. This will enable a wide variety of energy production sources to be used in cars - hydrogen fuelcells, biofuels, sterling engines, etc. And that kind of flexibility is where innovation will continue develop.

A couple of facts:

• The transportation sector generates 27 percent of U.S. GHG emissions

• There are 200 million registered vehicles in the U.S.,  almost one per person.

• The average U.S. car each consumes 600 Gallons each year.

• 12,000 pounds of carbon dioxide is emitted from one U.S. car each year.

• U.S. cars and light trucks traveled 2.7 trillion miles in 2004. That’s the equivalent of taking 10 million trips to the moon.

• Emissions for the first km are 80% of total emissions for the 4km journey.

• The U.S. produces 45% Percent of the world’s automotive carbon dioxide emissions.

• The Toyota Prius reduces normalized tailpipe emissions by up to 90% and greenhouse gas emissions by around 50%.

• The City of Ottawa estimates that reducing idling by only 5 minutes per day in all City vehicles will reduce greenhouse gas emissions by approximately 384 tonnes and save $80,000 in fuel costs across the fleet.  5 minutes!

         Sources: pewclimate.org, Evironmental Defense, University of Bath (UK), City of Ottawa

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