Friday, August 04, 2006

Let's Go EV

Or not...

Oh dear. Where to begin? Okay, first we are comparing brand new, cutting edge, designed for efficiency, small, niche vehicles to the 8.8 year old average US automobile (23mpg) in this efficiency comparison. Second, don't fall for the lie of omission in comparing electricity to chemical fuels. Only 31% of the energy used to make grid electricity actually gets to the customer. When that electricity is used to charge a battery this can be 60% but never less than 20% losses. So, getting useful work out of an EV is about 25% efficient. the claims of 0.3-0.5 kW-h/mile is 1000-1700 BTU/mile. For conventional vehilces 1.58 kW-h/mile is 5,400 BTU/mile or 23 mpg as calculated but the equivalency ignores passenger loads. While there is no definitive information it is highly likely that EV useage resembles the average occupancy of the commute segment of road users; 1.2 passengers while the US average is 1.57 passengers.

You see where I'm going with this, EVs are not anywhere near as efficient (yet) as their proponents claim. Within the next few years as solar comes down in price and/or increases in efficiency and as technology improves maybe but not yet. Oh, and it is important to note that a huge portion of the claimed transportation efficiency derived from EV designs can be applied to IC primary movers; low cD, narrow tires, limited capacity, range, advanced materials energy recovery, etc.

In short, every bit of advancement helps but there's no magic bullet here swithing to electricity from hydrocarbons.

Californians use 414.4 gallons of gas per capita per year (8th lowest in the US). 14.5 billion gallons. How much electricty is that? 530,982,417,478.593 kW-Hours. California can generate at present 46,000 Megawatts. We'd need and additional 61,000 Megawatts of energy to make it into the battery. Let's not mince words, we'd need 3 times as many power plants as we have now. Too hard to grasp? How about 28 new Diablo nuclear power plants (2x9.5 million mW-H reactors). Actually more like 40 Diabos. [insert lame ; "better the Diablo you know" joke here] And what would that cost? Nukes cost about $2000 per kilowatt to build. $122 Billion dollars. How much does that gas we Californians guzzle cost? $47 billion. Surprised? Gets better. Anyone here doubt that an order for 40 nukes could garner a volume discount? Yeah, like half price. A 50 cent per gallon surtax would pay the capital construction costs in 7 years. And what would the electricity cost? Remember we don't have any capital costs to amortize. 1.5-3 cents likely. We pay 14 cents now.

We could do it and it would make sense but we won't do it because of a combination of boiled frog syndrome and the cognitive dissonance of the eco-warriors.


Anonymous said...

You mean McDonalds doesn't generate enough waste oil to power biodiesel cars for everyone?

Mike D. said...

don't be too hard on the environmentalists. i consider myself one to a large degree, but i've made a complete 180 degree turn on the nuclear issue. the reality is we need a lot of power, and if you want to do it in a way that doesn't emit a lot of co2, then nuclear is really the only option that we can do w/ our current level of technology. we couldn't erect enough windmills to do this, and solar is nowhere near being ready to take this on, and we've already dammed every possible river.

a lot of environmentalists are starting to come around on nuclear due to the realities of the situation. we can push conservation as hard as we want (and should continue to do so, mostly w/ promoting more energy efficient products that still perform at levels that people expect, and also through pushing for better constructed buildings that need less heating/cooling), but the reality is that we need power, and nuclear could provide us w/ it.

Rob Dawg said...

I don't consider "cognitive dissonance" to be overly harsh on the eco-warrior subclass of all environmentalists. My frequent complaint illustrating the point is that blocking the completion of the 710 freeway in Pasadena has caused an additional 7 tons of pollution daily for decades. Another is the call for population control but advocacy for unfettered immigration.

When you get right down to it nuclear power removes the material from the environment and uses it up. There's less radioactivity after being used as fuel.

Anonymous said...

All good points. Here's a couple more on the technology side:

The current cost of high-quality lithium rechargeable batteries is roughly 1$/Wh, not including the management system. Depending on what range is desired and the type of vehicle (hybrid, pure battery), the battery cost alone varies from ~$8K-$40K. You may get as few as 500 cycles out of the pack too, depending on the environment (temp) and usage patterns. The batteries are more or less safe now, but the car itself runs at a considerable voltage, and certainly could represent a hazard. Still, plug-in (parallel) hybrids could help reduce our dependency on oil, although as you point out, they would do nothing to solve the energy problem.

Hydrogen you ask (apart from the fact that hydrogen is expensive to make, difficult to distribute, and is an indirect greenhouse gas...)? We'd have to see significant advances in maanufacturing technologies and near nobel-prize-winning catalyst research before fuel cells are cost effective for vehicle use.

Finally, alternative energies like solar and wind can only constitute 10-15% of the overall line power. They are relatively slow to respond to surges; any greater percentage would destabilize the grid. (In small, isolated systems like remote outposts, the percentage can be higher.) Even if their costs are reduced dramatically, it remains to be seen what impact they would actually have.

With such costs, it seems to me that the focus should be on conservation and improving the efficiency of the grid and system designs. Not glitzy enough for academe, though. Not enough of a driving force/resource pool to promote change in the commercial sector.

Anonymous said...

Thanks for breaking this down. This kind of analysis really helps focus thinking about a situation. My only concern is the $2K per KW construction cost on the price of nuclear and of course the assumed operating cost.

I know you made a point about diminishing the amount of radioactive material by using it, but disposal is a major concern and that cost needs to be accounted for in the process, or you get an unaccounted for benefit by externalizing the cost.


sm_landlord said...

"Only 31% of the energy used to make grid electricity actually gets to the customer."

I'm curious as to where you got that number. I have seen claims that the distribution system is as much as 80% efficient - not that I believe that number.

Did I miss it, or did you not include the cost of upgrading the distribution system to deliver all of that new power to the end user? That would have to be a big number, especially as the existing distribution system in California is already overloaded.

Anonymous said...

There is still so many possibilities for improvements in the old gasoline driven car. The Clinton administration made it a priority to improve mileage; the next administration scrapped the program and went on a dream journey with hydrogen :-( EVs make sense only in limited areas where pollution and noise are considered a bigger dawback than normal: on vacation islands, during smog (with the smoke generated hundred miles away instead or nuclear), etc.

Peter T

Anonymous said...

Don't confuse me with facts and figures. I want the government to force everyone to follow a central ecological plan because it makes me feel better. If only the rest of you could see my vision...

Rob Dawg said...


The transmission losses are about 11%. The plants themselves consume another 10%. The energy extracted from the fuel is about 70%. Conversion DC/AC up and down voltage is a few percent turbines are good but still only efficient in the low ninety percent range. Capacity goes unused to handle spikes. It all adds up to 31%. Now if you are Sweden and you use near all hydro you don't care. We won't care either as we increasingly supplement with wind/hydro/solar/tidal.

Here's a discussion of transmission losses:

And here's what our short sightedness has wrought:

And from:

About 12% of energy lost at boiler stage to heat losses

And remember, heat to work is not 100% efficient! So not all of the 88% of heat remaining gets turned into electricity. (Not all the heat from the steam is used to complete capacity in the turbine.) Once the steam is below a certain temperature it isn’t hot enough to force turbine to move and is dumped. Overall efficiency of the system is about 35%.

In reality, we try to capture some of that heat from the steam and put it to good use (not waste the initial energy used to create it).

Hot steam is passed through a condenser to cool it down to a point where it can re-enter the boiler. This does two things: 1. saves water in the boiler-turbine-condenser system, 2. allows us to use the remaining heat in the steam for heating water or steam heat systems.

Losses from boiler still 15%, losses from condenser 50%. Efficiency is still around 35% for generating electricity, but some benefit from “co-generation” of steam for other uses. Other uses of steam must be close by, otherwise heat doesn’t last.

Hydrogen is a twofold problem, the physics and the engineering. The physics needs a better way to make hydrogen. The engineering is just getting around the problem of a hard to handle material with low energy density.

CAFE requirements don't really work anymore. It is impossible to manipulate markets like that. High gas prices are doing what Congress could not and should not be doing.

On the same vein high gas taxes could work over a longer term with a fixed phase in. The problem is that invariably the revenue will be misspent.