[X] My Assistant

[crabbsaline]

I'm not sure when the countdown page went up, but looks like the first peek will come on July 20:

Tesla Motors Homepage

Random thoughts:

• I wonder how similar the batteries are to those used on the MERs.
• I wonder what the replacement costs of the batteries will be.
• I wonder what the best disposal of the batteries will be.
• I wonder when they will reach a price range that I can purchase one.

As a related matter, check out the competition:

Wrightspeed Homepage

I'm glad that Doug has this chat section. This seems far enough from the subject matter of UMSF that I worried about posting it. Five degrees of separation on this topic, I suppose...UMSF : Launch Vehicles : Falcon : Elon Musk : Tesla Motors.

[Guest_DonPMitchell_*]

If you factor in the efficiency of generating and distributing electricity from power plants, is it more efficient to have an electric car, or to power a car directly by gasoline?

[Guest_Richard Trigaux_*]

If you factor in the efficiency of generating and distributing electricity from power plants, is it more efficient to have an electric car, or to power a car directly by gasoline?

That depends on the energy source.

From oil, we gain the much better efficiency from power plants, and we lose the efficiency of the power lines and batteries. The balance must be positive I think. On environment, power plants pollute much less than car engines, and the better energetic efficiency also saves carbon dioxyd emissions.

But electricity can be produced from clean energies or dirty energies (such as nuclear). In these cases, it is more difficult to compare the overal efficiency (as we cannot do a car which would work with hydro power, for instance) but, I think, analyses show that, with any clean energy, electric cars make us win in both economic, environment, social or energetic sides.

[helvick]

That depends on the energy source.

From oil, we gain the much better efficiency from power plants, and we lose the efficiency of the power lines and batteries. The balance must be positive I think. On environment, power plants pollute much less than car engines, and the better energetic efficiency also saves carbon dioxyd emissions.

We do but it's not as clear cut as we might think. An oil fired station running on petrol (gasoline) would be very efficient but they burn crude (or very lightly refined crude) and their overall energy conversion efficiency is not much better than a car's engine.

The energy conversion efficiency of a standard oil fired power station is around 38%. The power transmission and distribution losses in delivering that power to consumers are around 9.5% in the US, best case 5% elsewhere. The conversion efficiency of the best electric storage and delivery mechanisms (conversion to energy store, reconversion and transmission to the motors and efficiency of the motors) is around 80%. Say 90% just to be safe. Overall energy delivery efficiency of an electric car using oil generated electricity is around 31%. Best case that would be around 37% for an advanced Oil Generator running at 44%.

Current petrol (gasoline) car engines have around a 30-40% energy conversion efficiency range while diesel versions hit 44% at the really high end. Transmission (gearing, oil drag, bearing friction etc) losses chew up around 10-20% depending on the car. So we have an efficiency range of 24-39% for normal internal combustion engine vehicles. Overall they are not that different and a good Internal Combustion engine could match a good electric only system if you wanted to build it.

The above calculation is a bit misleading though because when you fractionate crude oil you get only about 45% of the volume of petrol(gasoline) from the base fuel but you can basically burn the whole lot in an oil fired generating station. Still there is nothing stopping you burning the remaining 55% in a generator if you want so it's unfair to ding the internal combustion totally for that.

Things get more tricky when you compare the relative cost of generating power. The numbers have changed a bit over the past few years but from a few years back the relative cost of various electricity generation sources was:
Nuclear 0.33
Coal 0.33
Gas 0.82
Oil 1.00
(based on 2001 data in the US)
Since Oil and Gas have recently surged in price their relative cost has approximately trebled since then.

So an electric car powered by coal or nuclear generated electricity probably is arguably 8 or 9 times more cost efficient overall than a petrol(gasoline)\diesel internal combustion unit but you need to be clear about the fact that if the electricity is generated by oil (or gas) then that's not the case at all.

Coal and Nuclear power both have serious problems and alternative sources are still mostly more expensive than anything including oil at $75 per barrel..