In Search of the Energy-Efficient Family Car

Doug_G · Sep 9, 2013

Well here's a particularly lame attempt at "journalism":

Design News - Guest Blogs - In Search of the Energy-Efficient Family Car

When I entered this decision tree of what fuel-efficient car to buy, I initially thought that an electric vehicle (EV) would be the simple solution. EVs, which run on chargeable batteries, seem to make sense for our family. We live in an urban area and rarely take long trips requiring a long charge. We'll just plug the car in at night and stop using petroleum that pollutes the air. Right?

Not quite. As I started discussing the decision with my MEMS colleagues (all with their EEs and MEs), I quickly learned that it's not that simple. First, the biggest limitation is the battery itself. The energy-to-weight ratio for EVs is quite abysmal compared with gasoline. Up to one-third of an EV's total weight can be attributed to the battery pack alone, and most of the batteries hold a charge for a few hundred miles at best. That's a deal breaker for many.

It's end-to-end efficiency that matters, not the weight of the vehicle. EVs are vastly more efficient even if they are heavier.

A "few hundred miles" is a "deal breaker"? Geez.

Until we have cars that run on solar panels, energy is never free. Even if you decide to buy a Tesla, you have to think about where the energy is generated to recharge the battery every night. For me in Pittsburgh (and for most of the Northeast), the source is typically coal. Uh, oh. That means I would deplete more fossil fuels and release more greenhouse gases if I bought an EV.

Uh, no, since it is 3X as efficient as a gasoline car, you're actually doing pretty well even with coal - and you only have 48% coal.

Another important issue is the disposal of heavy-lead lithium batteries. Some EVs need to replace their batteries after three years. So if you are the average American who holds on to a car for five years, you'll need to dispose of (and pay for) two batteries and consider the environmental impact of that decision.

There is no lead in Lithium batteries. No EVs require new batteries after three years. Tesla batteries are warrantied for eight. There is no disposal issue as they are non-toxic and recyclable.

Let's face it -- the batteries for EVs (and for most consumer electronics) are still inefficient.

Dead wrong. They several times more efficient than internal combustion engines.

rolosrevenge · Sep 9, 2013

Plus Pennsylvania is turning more and more to natural gas. PJM actually has the most robust energy market in the US if not the world, anyone with a generator can get in and they run optimal power flow so the prices include transmission congestion caused by the generator. I've heard the director of PJM say that coal is getting killed by shale gas (fracking) so that no new coal plants are being built and the old ones are being replaced by high efficiency natural gas plants. So everything on her argument about where the energy comes from is wrong. Also, how about safety, that should be a big priority for a family car, what can beat the Model S?

brianman · Sep 9, 2013

Doug_G said:
We live in an urban area and rarely take long trips requiring a long charge.

Click to expand...

and most of the batteries hold a charge for a few hundred miles at best. That's a deal breaker for many.

Click to expand...

"Mommy, why don't we have an EV?"
"Because your father is retarded like Peter Griffin. We still love him though."

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In Search of the Energy-Efficient Family Car

Doug_G

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rolosrevenge

Dr. EVS

brianman

Burrito Founder

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