How much loss of energy between power plant and house? 2

[curtis74]

I'm trying to put together an intelligent argument against the use of household-charged electric vehicles based on several factors including the inefficiency with which electricity is delivered to the home. According to DOE reports, nearly 70% of the US electrical production is still coming from fossil fuels, so that little tidbit combined with how much of that energy actually reaches your house might make a rather persuasive argument.

Can someone help me out with a reference or website that might help me find out how much of the juice produced at the plant makes it to the average home?

 

[dpc]

I think you are barking up the wrong tree. Transmission losses in the electrical system are quite low. Because high voltages are used, resistive losses are greatly minimized.

Don't forget to factor in the energy it takes to haul the gasoline to the gas station.

I suspect recharging an electric car and running it via an electric motor powered by batteries is much more efficient than burning gasoline in the engine.

The power plants burning fossil fuel are more efficient than an IC engine, also.

 

[magoo2]

You're probably looking at 7 to 10% as a typical range of system "transmission" losses for the U.S. This range includes losses in the distribution system as well as the transmission system.

 

[curtis74]

Thanks for the replies. I know that they start out at really high voltage, but then they're stepped down in at least two steps. Doesn't it lose a bunch?

Fossil-fuel power production according to the EPA and DOE is only about 1/3 efficient; that is to say, only 1/3 of the stored energy in the fuel gets translated to electrical energy. That's very similar to a hydrocarbon-burning vehicle engine. I have to think that 1/3 efficiency at the plant, minus 7-10% in transmission, minus a bunch wasted charging the batteries in the car, minus the notable inefficiencies getting the power from the battery to the motors then to the ground still seems like such a waste comparatively. Thoughts?

 

[ScottyUK]

The better CCGT generating stations have over 50% thermal efficiency. Your car isn't going to beat that.


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If we learn from our mistakes I'm getting a great education!

 

[DonPhillips]

The power utility has an incentive to reduce the losses to maximize its profit. Although the world is full of compromises, I cannot imagine utilities have not looked at cost effective ways to minimize transmission losses.


Don Phillips

http://worthingtonengineering.com

 

[jfpe]

I remember seeing a paper on this topic published by the Society of Automotive Engineers a few years a go. They looked at the "well to wheels" efficiency of a number of drive trains. I believe they found the gasoline/electric hybrid was the most efficient, followed by the battery electric vehicle.
John

 

[curtis74]

Ok, 'nuf said. Thanks for the numbers.

 

[dpc]

Regarding transformers - most efficient energy conversion device in existence. Efficiencies well over 99% so not much is lost there.

Car engines are much less efficient than even a conventional fossil-fueled steam plant. All that hot coolant flowing through the radiator is basically waste heat.

 

[itsmoked]

I think IC cars are about 7-10% efficient.

Even with all the losses a battery car comes out ahead in the carbon game.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[cranky108]

Effecency is one thing, what about the cost of the fuel. Or the deversity of the fuel mix that creates the lower cost.

Or what about the lower maintenance of the components, other than the batteries. Not to say anything about the long life of the elements of the power grid, and the reliability.

Very few IC engines can get close to four or five 9's for reliability.

 

[rmw]

You are missing one other important factor and that is time of day considerations. There are certain times of day that the power companies have trouble meeting demand and don't need the added load of charging electric vehicles but that said, there are other times when the charging of electric vehicles would be very beneficial to them such as in the middle of the night when their demand is very low and they have trouble keeping units on line.

I have held and stated in these fora that when the power companies can send a signal via a multiplexer to a charger at the consumer's house to operate it in the middle of the night (or whenever they want to) when they need load in order to keep the units on line and operating at optimum efficiency and give a discount on the cost of the power sold at that time, the electric car will become a reality. Being the sluggish monolithic dinosaurs that the electric utilities are, I don't expect it in my lifetime, however.

Your answer came from jfpe. Google his words "well to wheel" and you will find what you need to know. It has been studied exhaustively and documented well. There are lots of losses getting that gallon of fuel to the fueling station.

rmw

 

[davidbeach]

rmw, look for AMI (Advanced Metering Infrastructure) to make a tremendous change over the next few years. The utility I work for will have two-way communications with all residential meters within the next few years.

 

[rmw]

David,

That is encouraging.

So would that give the ability to start/stop a charging device at will as I have suggested? And, would it give the ability to offer 'time of day' tariffs? Is there any hope of the utilities getting in on this thing? They could put the electric car on the map if they got on board with the concept IMHO.

rmw

 

[davidbeach]

Yep, all of that and more.

 

[cranky108]

I would assume that a rado signel could be used simular to the way utilities use to turn on distribution capacitors.

The technology is there, but so far the demand isen't.

As far as being sluggish monolithic dinosaurs, utilities are very economic and much slower to rise prices compaired to many other industries. And again utilities are in a very long life cycle business which happens to be very capitial intensive (The last part is the barrier to new competion, which is why utilities are very regulated by goverment).

 

[tlrols]

I think you should stop trying to form an opinion before you get the facts. Internal combustion enegines (the Otto cycle type) are terribly inefficient--the better motors might get perhaps 20% efficiency (with turbos, etc). Diesels do better due to the higher compression ratio and greater heating value of the fuel. NO utility scale power plant has efficiencies this low! Hydro power is very efficient (over 80%), thermal power plants are in the high 30 percent range, combined cycle power plants are usually above 50%.
Why is electricity relatively inexpensive (compared to gasoline)? Think about it. In 1920 a kw-hr cost 22 cents, today it might be 12 cents in a high priced market. Yep, we know how to make electricity in an efficient manner. The blended efficiency of a utility with a good mix of generation types is going to be near the 50% mark. Heck, just a few days ago the Mid-Columiba was "selling" electricity for -$1 per MW-hr...that is right, people were paying other people to take their electricity. Now, that doesn't happen that often, but when was the last time someone paid you to take gasoline, hmmm, let me think, oh, that's right, never!

As other have noted, the losses in transmission vary from perhaps as low as 3% to perhaps 7%. Various utility tariffs typically have them at no more than 5%. Distribution losses might add a few percent to this, but no more than this.

Your attempt to show that electric cars are NOT efficient is doomed to failure--it simply isn't true at all! You need to spend some time looking at unit conversions and convert kw-hr (of electricity) and BTU (of gasoline) to a common basis and compare the "mileage" on a cost basis. What you will find is that an eletric car gets "gasoline cost per gallon" of about ~$1 per gallon. In other words, electric cars simply crush gasoline fueled automobiles--the actual figures depend on electricity costs, type of electric car, etc. The drive motor on an electric car is over 85% efficient.

The reason electric cars haven't hit it big is due to a the limited range that present battery technology offers and the fact that oil has historically been quite inexpensive. For a short commute electric automobiles are quite effective--the problem is that big automotive companies have yet to make the neccessary tooling switches to make them in large numbers. GM's EV-1's were basically hand made. With gasoline at the $5 a gallon mark you should expect to see more conversions of internal combustion engines to electric motors occuring--simple economics will drive this. You can recover the $5k to $7K that the conversion will cost you quite quickly.

Bottomline: Electric cars are much more efficient than internal combustion motor powered automobiles--the free market clearly demonstrates this through the common unit of $$$$.

 

[QBplanner]

I am so surprised that in this forum, almost every body agrees that Electc. car is more ..... than Gaslin.. car...
But Ignore one important factor:
I don't know the other places, but in North Amerca, almost all major transmission facilities was built back to 40 years ago. One thing will happen is that after another 10-20 years, you will hate to pay your elect. bill when you see it.

The company I work proposed 5 Billlion reinforcement last year onlu on some cosmatic changes on our T/D system. I would expect after 10 to 20 years when we really start to upgrade all our 230/500kV system due to the aging and/or increasing transfer issues it may go up to 50 Billion. At that time, you will have a second thought of what your guys just said.

 

[dpc]

QBPlanner,

Transmission lines don't get less efficient as they get older.

Most of the grid improvements will be required regardless of electric cars or not.

The main point of discussion was efficiency, not cost.

 

[cranky108]

Hey here's an idea, lets send a wireless signel to allow electric cars charge only when the wind is blowing.
That would be a good way to balance out the effects of wind farms.