Let's face it, the Environmental Protection Agency's (EPA) miles-per-gallon-equivalent rating (MPGe) is a good estimate, but an estimate nonetheless. Battery-powered electric cars don't burn gasoline, so a gasoline-based rating is always going to be a theoretical exercise in energy conversion.
Still, the EPA needs some way to compare electric, hybrid, and gasoline-burning vehicles. Such ratings benefit government agencies and auto companies, as well as consumers who would otherwise struggle to compare kilowatt-hours to gallons consumed. The EPA reaches its hybrid and electric vehicle figures by running test cycles, determining how many kilowatt-hours are burned, converting it to BTU/mile, and then dividing that number by the BTUs in a gallon of gasoline. The result is the MPGe figure, which will undoubtedly be a source of technical arguments for years to come.
Click on the image below to see 12 of the top fuel-efficient vehicles, as determined by the MPGe rating system.
Ford Transit Connect EV -- 62 MPGe (combined city + highway): Ford's Transit Connect is a utility van with a top speed of 75 mph and an all-electric driving range of 80 miles. (Source: Ford Motor Co.)
You have used an apples-vs-oranges comparison to attempt to make your point. You used 20 MPG for the fuel-burning car, which is ridiculous. If you were to use a Prius, or even a Hyundai Elantra for comparison, the comparative gasoline costs would be 50% or even 60% less than your example.
So...now being more realistic - over your 100K mile calculation, the gas car would burn about $8 - 10K fuel (not $20.5K). I do actually believe your estimate of the electric car's charging cost. See: http://en.wikipedia.org/wiki/Nissan_leaf and look at the section on OPERATING COSTS. It agrees closely with your EV estimate (3.9 cents/mile or $3.9K / 100K miles). So, clearly the EV has lower "fuel" cost - to the tune of $4.1K-6.1K / 100K miles lower cost).
How much more did your EV cost vs. the equivalent conventional efficient car? (is it a Leaf, a Volt, a Tesla ?). The Volt is a great comparison, because the Cruze LTZ is almost exactly the same car, but without the EV. The MSRP's are: $40K = Volt, $24K = Cruze LTZ, for a delta of $16K. Therefore, the RAW break-even between these using the above numbers is between 260K - 390K miles. You're honestly never going to "break even"...but of course you can feel good that you are doing the "green" thing (burning coal+natural gas instead of oil....yeah baby).
OK...now let's put solar panels on your house roof. First, I'll comment that this is a WONDERFULLY green thing to do (MUCH greener than the EV choice). I am 100% pro-solar power, although it is still not cost effective vs. the grid.
If you look at the cost to put a panel large enough to fully charge your car - it will probably cost approx ~$30K (usually they muddy-up this figure with financing options, etc.).
So....add the $30K to the $16K premium you've already paid for your EV (and don't remind me of the EV convenience trade-offs...although the Volt admittedly minimizes these). So....$46K premium will now break-even in ONLY about $747K - 1.1 million miles !!! Good Gad....I hope your EV car and your panels last a really long time.
You mention that over 100K miles you believe that car maintenance would be an additional $12K vs. an EV. I don't believe this high number is representative of the average, but it is reasonable to assume that normal maintenance is lower on an EV. However, to be fair - if you include the BATTERY REPLACEMENT COST (somewhere in the neighborhood of $10K cost) at approx. 150K - 200K miles...this kind-of negates this argument.
My intent is not really to bash EV's...but I guess I effectively am, because they are not the great solution that they are being sold as....at least not with today's power grid.
I don't want to get into a pissing contest over EVs, but a bit more explanation: I have had four other ICE cars used to drive the same route from where I live for the past 35 years. I have a good record of what the average mileage I get turns out to be in the kind of traffic conditions I drive through every day - 32 in, and 32 out! That average turns out to be 20 MPG(like it or not) through a Ford, a Jeep, and two Acuras! Since I live in an outer bedroom community, WE GET HOSED with the price per gallon of gasoline! Averaging out over the last 5 years, we come out to $4.10/gal (like it or not).
The electric I drive happens to be a company car, and I am driving the same route for the last 2 years with this car. I have verified my cost to charge it with So. Cal. Edison, and the unit cost is programmed into the onboard computer in the car control panel. The cost to charge is displayed every morning on the monitor. Add it all up for the last 38,000 miles, and I came out with the cost/mile I gave you. The same thing was done for the price of the gas I burn, and the cost differential stands(like it or not). I am not saying that the EV is the end-all for everyone, but let's take a look at the overall landascape for a minute.
Yes, the current price of entry is high for the EV! The power generating in our area just happens to be natural gas (Edison has done a great job of controlling pollution at the point of generation with natural gas). Granted, not all areas use natural gas! But let's look at more of the costs of driving ICE cars. More than half of the cars on the route I drive are occupied by one person, many of them 5,000 lb. SUV's with one person on board. Look at the cost of trying to control these mobile sources of pollution, many of them not smogged or properly maintained, many of them dripping fluids and blowing oil. Everytime it rains in our area, you are not advised not to go to the beach for a week simply because of 10,000 square miles of polluted pavent petrolium products that poison our coast and damage what lives there. The company bought the car as a way of trying to get the ball rolling on some possible alternatives. I happen to be in a position to drive the vehicle, and it has serve well for the last 38,000 miles! Those who drive an EV for the first time realize that the driving experience is a whole new thing. As other manufacturers pile on with their own EV's, the price of entry will fall, the total cost of ownership will fall, and more people will leave the 5,000 lb. bolt bucket at home for the weekend activities like towing the boat, kids, and toys.
At some point, the electric drive will be doing some heavy lifting. One truck manufacturer is already in prototype stages of testing electric drive. Apparently the instant low-end torque of that drive looks like a very attractive alternative to the straight diesel.
By the way, it sounds like you did not yet go to the Solar City sight. Please do so and I believe you will find that you don't pay for the cost of installation. The value of the power generated by the panels is split up between you, solar city, and the power company. The net result is that you end up with a monthly payment that is a fraction of the normal bill/month you would pay out to the power company without the panels. All of the equipment is maintained and updated by Solar City. I may not have the EV much longer, but the panels will remain, and I will be very happy paying a whole lot less to Edison anyway!
Regarding your 8/20 post, the Forbes article is all wet. Its author makes a big deal about making a proper apples to apples comparison and then he makes the same mistake. He tries to arrive at an end-to-end MPGe comparison, except that the EPA's MPG ratings for ICEs, against which MPGe is based, are tank-to-wheels, not refinery-to-wheels. Ergo an MPGe rating for EVs which is wall plug-to-wheels and not power plant-to-wheels. True, it would be useful to have a comparison closer to well- or mine-to-wheels, and that would help favor gasoline in terms of total energy, but that is not what the EPA MPG ratings do. Moreover, the document the author references to make his point (Fed. CFR) actually uses a longer formula (PEF) to compare energy from oil to that for electric power for propulsion. Yet the Forbes author selectively omitted the full formula, which multiplies the energy equivalence from electric power by a "fuel content" factor of 6.67! One can argue that it's unfair to do that, but you can't selectively pick and choose from your favored authority without explanation. It's not apples to apples.
MPGe notwithstanding, what is important to compare is the cost of energy and the relative amount of greenhouse gases (GHG) produced, as far back in the energy chain as reliably possible, which is the refinery or the power plant (--good mining/drilling energy intensity data is hard to find and compare). I can corroborate that the Nissan LEAF fuel costs equate to ~100MPG at <$3/gal. So EVs win that in a slam dunk. Regarding GHGs, a pure coal-fueled EV would produce the same amount of GHG (plant-to-wheels) as a gas (ICE) powered car that gets something in the mid-30s to mid-40s MPG, depending on the numbers you find to make the calculations. But the electric grid is less than 50% powered by coal and that percentage continues to fall. So EVs are pretty darn competitive w/r/t GHG now and getting cleaner with the grid all the time. By contrast, high MPG gasoline cars will never break free of expensive and GHG-intensive fossil fuels. Major algae biofuel breakthroughs would be needed to change that.
Regarding PV costs and EV payback, @Kevin states that it would probably cost ~$30k for a PV system that will fully charge an EV. I paid about half that for my 2kW PV system BEFORE the 30% fed tax credit and this system produces enough to "fuel" my LEAF ~7k mi./yr including charging losses. Moreover, the price of raw PV panels is now less than half of what it was when I bought mine. When I roll in the price that my utility pays me for my green power into my fuel savings by going EV vs. gasoline, my PV payback time is reduced to ~6-7 years.
Nobody is saying that you can yet buy an EV and save money during the expected life of the vehicle over a comparable ICE car, e.g., Cruze vs. Volt. It's not about everybody always doing what's best only for his or her own pocketbook. That's why there are incentives for early adapters to help drive EV costs down. For now the Nissan LEAF is a low volume car expensively built in Japan. The similar Versa model is a high volume car built in Mexico. Therefore economies of scale have at least something to do with this.
Also, I think @gwf_fly is trying to make a point that I would also make, which is that there are intangible and unaccounted benefits that people usually skip over when considering EVs, though they never fail to skip over EVs' costs and risks. For example, in almost a year and a half and over 14k miles of driving my EV, I have opened its hood only to show friends. Nothing else. It's not just the savings in maintenance costs, though those are significant. It's the hassle, time, and management I no longer have to put into car maintenance. Further, what are the benefits of a near silent and vibration-free car? What value does that add for buyers? Don't they compare in part on that basis and isn't it reasonable that they would pay more for a vehicle that is superior in this respect? Would it surprise you that a Lexus, say, might be considered to be worth $500-$5,000 more than its peers on the basis of its refinement with respect to noise, vibration, and harshness? Well, an EV is considerably smoother and quieter than the best Lexus, approaching the ideal in that regard. It's almost magical-like and rewarding every time you travel! Isn't this worth SOMETHING in the purchase price?! Yet, I never see EVs awarded any value at all for such benefits.
The new 2013 hybrid Ford Fusion has earned the boasting rights to call itself the most fuel-efficient mid-size car in the land. Its EPA score nears the Prius liftback for mpg. You can buy junk car that works flawlessly or something new. It's a reason to buy Ford vehicles, with customers able to choose the fuel-efficient powertrain that best fits their lifestyle.
My LEAF gets about 4.5 mi./kWHr. I drive it about 800 mi./mo. I pay on the high side for electricity at $0.14/kWHr. (including all the fees and taxes) because I live in San Diego. That's about $25 per month for 800 mi.
You can charge at 120 VAC if you have a 15 A circuit that is available at night. It just takes 2.5x longer to charge. That still gieves you a full charge overnight.
Here's another data point. The LEAF I own averages 5.2 mi/kWhr. If I were to convert to an equivalent mpg - it would be 185 mi/gallon. Compared to an ICE getting 25 mpg, my fuel cost is 1/12. I pay around 9c/kWhr with time of use metering.
The EPA rating for the LEAF is correct and I have no beef with that since the testing technique is standard. The penalty for poor driving technique is very high in a very efficient machine, not so for an inefficient gasoline engine where only roughly 20% of the energy of the fuel is converted to traction. At the same time, there is potential to extract high efficiency with an EV as well. I have a 60 mile round trip commute and I charge only to 80% (to reduce battery degradation). I come home with around 15 mile range left. That clearly beats the EPA rated measurement (73 miles) which also assumes charging to 100%. Also, the 24kWhr capacity is not all useable (to protect the battery). Once EVs with 150 mile EPA ranges are available, there should be no range anxiety for most.
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