When I was a member of City Car Share, before my wife, daughter, furniture and car came out to join me in the bay area, I got to drive a Prius around. It was kinda cool. It could be erily quiet at stop lights, it got up to highway speed well enough, if occasionally hesitant. But one of the things that amused me most about it was a sticker on the window. It took me a while to actually read the fine print. There are so many stickers on cars these days; state inspections, oil change timings, radio theft warnings, AAA finders fees, you name it. This sticker had in large letters PZEV. It wasn’t until I examined it more closely that I read what it stood for. The prius is a “Partial Zero Emissions Vehicle”.
Now, I was never a math rockstar, but as I understand the word “partial” it means part of which would imply a fraction. Let’s take the fraction 1/2 of, say, 6. We take 6 and multiply it by 1/2. The result is 6/2 or 3. You see where I’m going here, right? Now, let’s take 90% of 0. 9/10 * 0, well, it’s still 0. There’s an infinite number of partials of zero, but, well, they’re all zero. And the prius is not a zero emissions vehicle.
Of course, even pure electric vehicles aren’t zero emissions; that electricity has to be generated somewhere. As far as I know, the US has 3 primary ways of generating electricity: Coal, Hydro, and nuclear. Which of these do you want in your backyard?