Frank - sorry, both swags on coal/KWh and CO2 are incorrect. Using real figures (too involved to show) result in a Nissan Leaf (if charged by only coal plants) has ~23% more CO2/mi vs. Toyota Prius. In reality the grid is a mix, result: EV's have slightly more CO2/mi on avg. (10%-20%).
I am not bashing EV's, but please don't believe the bogus numbers the EPA and others are showing. CO2 output is not the top comparison anyway, IMO. The point is - we need to focus on powering the grid with renewables before EV's can have their day. It's a sequence thing, a cart before horse, not that EV's are bad.
km6xu - Electric motors are indeed efficient but you need to include the entire energy stream from fuel-to-wheels (or well or mine -to-wheels, which gets murky). Coal plants are ~32% efficient, natural gas a bit more (avg ~35%, with some new ones up to 58%). A prius's gasoline burning engine or a VW TDI can also be around 35% thermally efficient. Don't believe the 20% efficiency used by EV proponents - this is for old V8's. If you take the Leaf's EPA 99 MPGe (based on KWh out of the plug) and adjust for avg grid efficiency - 99 x 35%-50% (depending on assumptions) = 35-48MPGe, you can see that the energy used is about the same as a prius or VW TDI. No free lunch.
Net-Net, the total energy used, total fossil fuel usage, CO2 output, and overall efficiency of EV's is about the same than the best hybrids and turbodiesels (using USA avg grid). Shifting from oil to coal+nat gas has merit - but the URGENT need is to get moving on changing our grid to renewable sources, and until then EV's are mainly a costly distraction. At least plug-in hybrids allow the best of both worlds - albeit at high price.
Also, as my prior posting mentioned there are other ways to make fuels for cars that are renewable and net-zero-CO2 and can leverage today's cars and gas stations - and not burden the electric grid infastructure with it or have huge convenience trade-offs.
You don't generate hydrogen at home but rather in safe industrial facilities. Storing it in metal hydrides avoids the high pressure. Also, it might be handled in proper pressurized containers, similar to natural gas which is not generated at point of use either.
Indeed the Volt and Prius are different vehicles -- one draws electricity from the grid, the other generates it's own power, effectively extending the mpg of its gasoline engine.
I am not opposed to pure EVs at some future date when we are ready for that transition. kkersey (above) said it best -- "Once the grid is mainly powered by renewable sources, then EV's could make sense, but not NOW. Best-case, this will take decades."
Sure, decades from now, we might be generating a large percentage of that required electricity from solar, wind, or even nuclear fusion. But not today, and not by 2015.
Why are we so scared of change in this country now? Scared enough to report the Leaf's range as less than half of what it is? Scared enough to imply that EVs will depreciate while gas cars won't? And certainly scared enough to ignore all external costs of gasoline, and pretend that all we pay for gasoline is what it costs us at the pump.
Our way of life, our standard of living... they're both dependent on our supply of oil coming from outside our borders. We can ignore the pollution aspects of our fuel - there's enough to worry about just from the political and economic aspects of driving around on imported fuel. 45% of our trade deficit is spent on oil - the largest transfer of wealth in the history of our country. But we don't care. We like driving our 18 mpg cars. And we do what we like, not what's best for us.
When did we become a nation of "can't do?" What happened to the resolve we had back in the Sputnik era? Back then we wanted to be the best nation in the world. Today we're happy to sit back, get fat, and stick with the status quo until that's no longer an option. Meanwhile, other nations eat our lunch.
No, like most people in north america I have not tried to buy a Leaf or a Volt. Thank you for your lecture on what I should consider in buying a new car, I never thought about the fact that I'll have to buy fuel for it!
Here is some math...if you drive 10,000 miles in a year and have a vehicle that gets 18 mpg (like my SUV), at $4/gal you'll spend an extra $1100/year on gas over someone driving the same miles in a 36 mpg mini-car. It is absolutely worth $1100/year to me to drive an SUV. A $40k nissan leaf is going to cost an owner something like $3,000/year in depreciation, and when you factor in buying a new ($10,000?) battery pack every ~7-10 years, the price gets steeper. There is more to a transportation cost equation than the price of gas.
I'm not sure if you have ever tried to buy a Nissan Leaf, or a Chevy Volt for that matter. Last year, 13,000 people paid $99 each for a reservation, and that was within one month (May 2010) after Nissan announced the vehicle. I've been on the waiting list for a Volt for half a year now, and there is no indication I'll get a Volt this year. Your statements that "it is not a supply issue" and "hardly anyone in the US wants to buy an EV" are laughable and frankly rather ignorant of the demand of EVs and PHEVs that the US population has shown time and again starting with the EV1. When you buy a new car, you have to think about the price of gasoline over the next 10 years, and it seems that more and more people are aware that the time of cheap oil is over, and the time to drive on an alternative power source is upon us.
A Volt and a Prius are two different vehicles, so you cannot directly compare them (for CO2 emissions).
But we know that a Volt (running gasoline only) gets 32(city)/36(highway) mpg, which means it emits some 0.6(city)/0.54(highway) lbs CO2/city-mile when running gasoline only.
This means that the Volt emits less CO2 in electric mode, even when it is powered by a coal-fired power plant.
Not to mention the reduction in other, more traditional, pollutants when driving electric.
That website is reporting North American sales. As Leaf production ramps up, most of them are being sold in Japan, and availability here is stifled.
For the record, the car is advertised as having a 100 mile range, and real-world experiences are in the same ballpark. The car is expensive when only up-front costs are considered, but it comes through when operational costs are factored in.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Are the design challenges the same as with embedded systems, but with a little developer- and IT-skills added in? What do engineers need to know? Rick Merritt talks with two experts about the tools and best options for designing IoT devices in 2016. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.