I am with you - the hydrogen is the solution with no pollution as long as it is generated from renewable resources - solar and wind. Both of those are intermittent and hydrogen can ideally serve as energy storage (buffer). As soon as a reliable high density storage is developed (along the metal hydride approach or similar) hydrogen coupled with fuel cell is ideal solution for transportation. Never mind poor efficiencies of the current solar cells - even with today's generation of cells there is 150W/m2 power available. Consider vast areas of the desert in SW US: an area of 50 mi square could with current solar cell technology supply the entire generated power needs of US (while sun is shining). Improving the efficiency of solar cells in the future will make the picture even better as will using the heat (IR) part of the spectrum for running conventional steam power plants. All this without any contribution to greenhouse gases.
You got me! Alas, no editing capability on these forums. Note to self, always double-check the math before pressing the Submit Comment button.
Notwithstanding my order-of-magnitude error, the fact remains that purely electric EVs contribute significantly to greenhouse gases due to increased demand from the power grid and the need to burn fossil fuels to meet that demand.
Compared that with hybrids like the Prius, which gets around 50 mpg. Let's see if I can do the math right this time:
19.4 lbs CO2/gallon / 50 miles/gallon = 0.39 lbs of CO2 per mile for a Prius or similarly efficient hybrid.
Not so dramatic, but still less than the 0.49 lbs of CO2 per mile for the Volt...and without building new power plants or charging stations, mining more coal, etc.
Chris, somebody nearby here got a Nissan Leaf that (after the government incentives, ugh) was about $22K. The power grid is darn near everywhere, and charging stations are popping up all over the place thanks to both governmental and private efforts. With a little help from google, you should be able to find maps showing many, many charging stations. You are right that much more than cute speeches are necessary; societal will is needed to wean us Americans from Middle-East oil.
Frank, given that the MPGe rating of an SUV is about half that of the Chevy Volt, I suspected a mistake in the analysis, so I gave it a second look. If the Chevy Volt produces 49 pounds of CO2 per 100 miles, that equates to 0.49 pounds per mile, about half that of the SUV.
GM, Nissan, Toyota, Ford and other car manufacturer put in so much of effort for this next generation EV vehicles. They must have evaluated overall scenario and taken the plunge into it. Can these car manufacturer's spokes person explain their logic behind going for EVs and hybrid technology?
Here's more food for thought:
The Chevy Volt consumes an average of 36 kWh per 100 miles in all-electric mode. According to the U.S. DOE, it takes 2.1 lbs of coal to produce 1 kWh of electricity.
Transmission & distribution losses in the power grid are estimated at around 7%, lithium-ion battery charging is about 98% efficient, and let's be generous and assume that the losses in the cable connecting your car to the electric outlet are only 1% -- that's a total of 10% in losses between the power plant and usable energy stored in the batteries in your all-electric car.
So the power plant needs to generate close to 40 kWh of electricity -- by burning over 80 lbs of coal -- to enable your Volt to drive 100 miles. That 80+ lbs of coal burning will add about 49 lbs of CO2 to the atmosphere, or about 4.9 lbs of CO2 per mile driven.
The U.S. EPA's calculation for CO2 emissions by gasoline-powered cars is 19.4 lbs of CO2 per gallon of gasoline.
Even a gas-guzzling SUV that only gets 19.4 miles per gallon will emit just 1 pound of CO2 per mile -- 5 times less than the supposedly "green" Chevy Volt.
The real trade-off in the move to EV's is American coal vs. Middle Eastern oil, but at a cost of much higher greenhouse gas emissions.
"despite the fact he knows next to nothing about technology and engineering"
I was very impressed by the McCain Palin paper at last year's SAE conference. It's such a shame that we were deprived of their engineering leadership.
Ron Wilson and Frank Eory have it right. Once the grid is mainly powered by renewable sources, then EV's could make sense, but not NOW. Best-case, this will take decades. Today, the grid is 50% coal and nearly 25% natural gas (and 20% nuke). EV's use just as much energy (at the power plant) as a hybrid burns fuel, and coal actually produces 1.5X the CO2 per energy unit. Therefore, TODAY EV's make NO sense, not even considering the high costs, convenience tradeoffs, and lack of charging infastructure. Hybrids or efficient turbodiesels are practical today, and save equivalent amounts of energy. Longer term, biofuels or solar synthesized fuels (www.guardian.co.uk/environment/2010/dec/23/reactor-fuel-sunlight ) can power today's vehicles with renewable and net-zero-CO2 fuel. As a stop-gap measure if oil sources get too unstable: LNG works OK, and synthetic gasoline can be made directly from Coal, of which the USA and Canada have large amounts (the Chinese are doing this - see: http://www.exxonmobil.com/Apps/RefiningTechnologies/files/article_CoaltoLiquids_HydrocarbonEng.pdf ). EV's are only one way to get off of oil - and are probably not the best way, at least for now.
Government mandate has NEVER been the key to innovation. If the manufacturers are left alone, or incentivized, the WILL come up with a vehicle that is affordable, but not likely in the next couple of years. After all, the Volt will only go 40 miles/charge. I have to drive 37 each way, so it would be pushing the technology just for me to get to work.
And just because the vehicle is electric, doesn't mean we aren't burning a lot of fossil fuel to charge them!
Just another issue that Obama is ignorant on. He continues to believe it he says it, it WILL happen, despite the fact he knows next to nothing about technology and engineering.
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.