Electric Vehicle Plug Standard Coming In July?

SAE J1772 is supposedly going to ballot for this month for final approval. This would be a good move toward standardization of infrastructure and hardware. The SAE (Society of Automotive Engineers) process typically takes a few years for completion
of a standard or recommended practice so the outcome is generally well vetted by the industry.

Source: AutoBlogGreen

Nissan To Introduce EV In 2010?

This would be quite an accomplishment if Nissan can introduce an EV next year that is price competitive with conventional vehicles in that segment. I'm curious what kind of range (supposedly 100+ miles) and functionality it will have, and how widely available it will be; probably Southern California and possibly only for fleets at first.

Click here for AutoblogGreen's article.

Gasoline Buffers

The main obstacle of electric vehicles is energy storage media. A gallon of gasoline or diesel fuel is about 6.5 lbs. The equivalent weight in batteries is in the neighborhood of 205 lbs. This is akin to carrying a memory stick with gigabytes of capacity compared to reels of film or floppy diskettes.

But there are many advantages to electric power such as the ability to decouple vehicle speed from engine speed, energy recapture during braking, silent operation, and no emissions when operating in electric mode. These factors add up to considerable potential energy savings.

This is why there are numerous projects aimed at developing series hybrids (the Chevy Volt being the first that comes to mind). In other words gasoline and diesel are excellent energy storage media while electric powertrains are much more efficient. So the challenge is to somehow combine the better aspects of the two in order to achieve a superior solution, and putting in place the infrastructure to support pure electric power when the energy density of batteries (or capacitors, etc) have matured sufficiently.

Right now that appears to be a revolutionary chassis combined with a small IC engine and electric drivetrain. By that I mean cars that are dramatically different and lighter than existing vehicles. Conventional designs fitted with electric power wouldn’t be nearly as much of an improvement. We should strive for major gains by thinking further outside the box.

Gasoline to Battery Range Comparison

One tank of gasoline contains hundreds of millions of Joules of energy (MJ), about 45 MJ/kg according to Wikipedia. Let’s say your typical car is 3,000 lbs in weight, has a range of 350 miles on a tank of gas, and gets about 30 mpg highway.

By contrast a Nickel-Metal Hydride (NimH) battery is good for about 0.22 MJ/kg. For the sake of discussion, using today’s technology how much battery mass would it take to provide the equivalent?

At 30 mpg it would take 11.67 gallons of gas to go 350 miles. If each gallon is roughly 6.5 lbs, then we have roughly 76 lbs or 34.5 kg of gas. Based on 45 MJ/kg that’s 1,552 MJ of energy.

We know a 350 mile range would be too far for batteries. So how much would the market accept as an alternative? Let’s assume 2/3 of that which would be 210 miles. For the same vehicle then 210 miles would require 2/3 as much energy which would be equal to about 1,035 MJ. But keep in mind that a gas engine is about 25% efficient whereas an electric power train is closer to 75%.

That means if you’re using 1,035 MJ of gas at 25% efficiency, you would only need about 345 MJ of electricity (1,035 x 0.25 / 0.75).

Using battery tech with 0.22 MJ/kg we’d still need an astounding 1,568 kg (or 3,456 lbs) of batteries. No wonder the ranges being discussed for plug-in hybrids (PHEV) are more often in the 50 to 100 mile range, using lithium batteries.

However, all is not lost. If we can pare the weight of the vehicle down from 3,000 lbs to say 1,500 lbs we can probably save another 1/3 in the energy for the same range. If that was done battery mass would come down proportionally to 1,045 kg (2,305 lbs). Still not practical but that’s for a 200 mile range. If the range were cut to 50 miles then it looks like we could get away with less than 600 lbs of batteries (2,305 lbs x 50 miles/200 miles = 576 lbs) if the car is very light. This does not yet account for the weight of the batteries either.

It’s clear there are only 3 main ways to increase PHEV range without additional fuel:

Improved battery energy density
More efficient powertrains
Drastically lighter vehicles

While there’s a lot of work being done on improving battery technology, it should be noted that dramatically lighter vehicles will strongly contribute to the growth of PHEV vehicles. And in doing so we’ll probably see a lot of refreshing concepts in the very near future.

Mobile Billboards, Not Green

This is a perfect example of doing the wrong thing well. Why on earth are there companies that operate trucks that do nothing (e.g. transport cargo) but drive around adding to congestion and taking up space? Plus they’re adding to congestion because billboards would be less effective if there was less traffic around.

Then they suggest this is somehow environmentally conscious. Some times people lose sight of the point that the green movement isn’t to waste electricity instead of oil but to reduce our overall waste. How does a person even say this with a straight face?