Comments on: CO2 & You http://everydaydriver.com/awarnings/co2-you/ Putting the "Rush" back in Rush-Hour Mon, 14 May 2012 18:08:01 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Ryan Ballantyne http://everydaydriver.com/awarnings/co2-you/comment-page-1/#comment-5287 Ryan Ballantyne Sun, 12 Feb 2012 08:21:43 +0000 http://everydaydriver.com/?p=466#comment-5287 The argument for electric cars does not ignore the dirty source of electricity. Nobody who knows anything about the range of "green" car power technologies is making the argument that electric cars result in zero carbon emissions. Rather, the argument is one of flexibility and efficiency. ICE-powered cars can only burn one (or two) types of liquid fuel. We can increase the efficiency of the engine, but we are otherwise stuck. Electricity, on the other hand, can be generated from a diverse mix of sources, and while we may at some point achieve a truly sustainable electric grid, gasoline will never be sustainable. With electric drive, we gain the flexibility we need to get to zero emissions. As for efficiency, internal combustion is crap. Well-to-wheels, we would use a lot less petroleum if we burned it to make electricity to power our electric cars than we currently do burning it directly. Now, I will temper this comment with the caveat that I haven't looked at figures since 2005-ish, so the latest direct injection engines may have improved matters, but I am skeptical that they've even broken even with large-scale generation coupled to super-efficient electric motors. The secondary argument in favor of electric vehicles is that they do a lot of things better. Electric motors have a comparatively flat torque curve, and provide it starting at 0 RPM. Electric motors have a single moving part, so reliability goes through the roof. The heater isn't tied to the temperature of your engine, so you get hot air very quickly. And so on. The one downside - and it's a big one - is charging time. We now have batteries that are capable of accepting a full charge in 5 minutes. Unfortunately, actually delivering that much power that quickly to the batteries is a significant engineering challenge, and it may even be physically impossible to do within the safety, cost, and weight constraints of automotive applications. This hurdle would need to be overcome just by increasing the power density of our batteries. Put 500-600 miles of range in your EV, and suddenly charging time isn't such a big deal. The argument for electric cars does not ignore the dirty source of electricity. Nobody who knows anything about the range of “green” car power technologies is making the argument that electric cars result in zero carbon emissions. Rather, the argument is one of flexibility and efficiency.

ICE-powered cars can only burn one (or two) types of liquid fuel. We can increase the efficiency of the engine, but we are otherwise stuck. Electricity, on the other hand, can be generated from a diverse mix of sources, and while we may at some point achieve a truly sustainable electric grid, gasoline will never be sustainable. With electric drive, we gain the flexibility we need to get to zero emissions.

As for efficiency, internal combustion is crap. Well-to-wheels, we would use a lot less petroleum if we burned it to make electricity to power our electric cars than we currently do burning it directly. Now, I will temper this comment with the caveat that I haven’t looked at figures since 2005-ish, so the latest direct injection engines may have improved matters, but I am skeptical that they’ve even broken even with large-scale generation coupled to super-efficient electric motors.

The secondary argument in favor of electric vehicles is that they do a lot of things better. Electric motors have a comparatively flat torque curve, and provide it starting at 0 RPM. Electric motors have a single moving part, so reliability goes through the roof. The heater isn’t tied to the temperature of your engine, so you get hot air very quickly. And so on.

The one downside – and it’s a big one – is charging time. We now have batteries that are capable of accepting a full charge in 5 minutes. Unfortunately, actually delivering that much power that quickly to the batteries is a significant engineering challenge, and it may even be physically impossible to do within the safety, cost, and weight constraints of automotive applications. This hurdle would need to be overcome just by increasing the power density of our batteries. Put 500-600 miles of range in your EV, and suddenly charging time isn’t such a big deal.

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