Wind and Geothermal Energy Generation

[Wise Young]

It is quite an interesting idea. Collect the winds on our highways, convert the energy to hydrogen fuel cannisters that the cars can use, or use the energy to run a train alongside the freeway

I was at a meeting recently and spoke to a very impressive guy who is the head of a major biotech company but is also organizing a geothermal energy company. They are using these special drilling devices that can take water pipes 3000 feet or deeper into the crust of the earth in a circular loop. Equipped with appropriate valves, water pumped into the pipe will be turned into steam which can run generators to supply free energy. He suggested that the cost of such a device that would supply electricity for a 20,000 person community is about $15 million. Wow, I said. That is only $750 dollar per person. Just one year's utility bills for 20,000 people at $100/person would be $20 million. That is like free energy, a no-brainer. Here is a nice 14.1 Mb pdf file that outlines the future of geothermal energy http://geothermal.inel.gov/publicati...mal_energy.pdf for people to read.

Wise.

http://www.ecogeek.org/content/view/524/

Stand near a busy roadway and you'll be buffeted by gusts of wind as cars pass by. The majority of energy used in highway transportation goes to move huge volumes of air out of the way of our vehicles, not moving the vehicles themselves. So why not harness that energy and make it something useful?

That was the thought of Mark Oberholzer, who proposes installing small vertical-axis wind turbines inside 'Jersey barrier' highway dividers to drive electrical generation. "Opposing streams of traffic create really incredible potential in terms of a guaranteed wind source," Oberholzer says.

[alhavel]

Wise, you come up with the greatest things, or, knows of someones tinking in the same manner, but. Living in the tri-state area all my life, you can't help noticing the addiction for cars and trucks to the divider. So, does it still pay off? Anyone trying to change a tire, or secure luggage will agree, that this is a tremndous amount of energy, especialy on roadways that have been sound proofed with walls on all sides. Hell, just the electricity alone could probly call for an end to the dreaded Jersey Toll Booths. Good thinking,

[alhavel]

So,,,,,, The higher the rate of speed, especialy above the speed limit, you should be actualy entitled to an energy credit, vs. an enforcment fund contribution?

[rfbdorf]

It is far more efficient to design cars that do not push so much air around in the first place (less drag, less cross-sectional area), than to push the air around and collect a fraction of that energy. Additionally, a huge amount of enery can be saved by travelling slower - the energy used to move the air around increases by the square of the speed. If you travel at 70 mph rather than 50 mph, you're increasing your speed by only 40%, while throwing away nearly 100% more energy.
Of course all that is the same as improving the passenger miles per gallon of fuel used. One novel idea is to string cars together so only the first one has to push the air aside. Hmm, maybe you could run this train of cars on rails so you don't need rubber tires or a wide highway. Less people would crash into each other, too. Or maybe just carry a bunch of people on the highway in a single large car - you could call that an omnibus.
- Richard

[rfbdorf]

As to geothermal energy, the city of Klamath Falls in Oregon has been using that for many years. Of course, it helps that the city is built on top of hot springs.
- Richard

[Wise Young]

Originally Posted by alhavel

Wise, you come up with the greatest things, or, knows of someones tinking in the same manner, but. Living in the tri-state area all my life, you can't help noticing the addiction for cars and trucks to the divider. So, does it still pay off? Anyone trying to change a tire, or secure luggage will agree, that this is a tremndous amount of energy, especialy on roadways that have been sound proofed with walls on all sides. Hell, just the electricity alone could probly call for an end to the dreaded Jersey Toll Booths. Good thinking,

Alhavel,

There is so much wasted energy. Even travelling at the speed limit, cars and trucks are moving significant amounts of air. As rfbdorf pointed out in his post, travelling even 10-15 mph below the speed limit can save a considerable amount of energy and can reduce gasoline usage by 25% or more. This suggests that about 25% of energy used for travelling on freeways is due to moving air. The New Jersey Turnpike is possibly the most heavily travelled highway in America (Source). I don't know how many cars travel on the Turnpike everyday but let us assume that it is 10 million cars each using a gallon of gasoline during their travel on the turnpike. 25% of the 10 million gallons of gasoline is 2.5 million gallons of gas! Please note that there could easily be 100 million cars per day travelling on the New Jersey Turnpike per day and the number would be tenfold higher. So, even if 10% of that energy can be captured from the wind, that would be a lot of energy.

It was also occurring to me that the momentum of the propellers capturing the wind would tend to create a vortex that will move air out of the way of the cars. In other words, a wind capture device may actually increase the efficiency of the cars travelling on the highway. It would be sort of like a wind tunnel effect or the advantage of riding your bicycle behind another one that is breaking the wind. So, a side benefit of capturing wind for energy along the highways would be significant improvement of the gasoline mileage of cars travelling on the turnpike.

Now, we need to multiply the above two effects by all the freeways and highways in the United States.

Wise.

[Wise Young]

rfbdorf, I love your omnibus idea. Could this be one of the reasons for having multi-trailer trucks?

Most people people don't realize the enormous influence of aerodynamics in their gas mileage. We have had several extensive discussions of this, including one that showed that aerodynamics is a major reason why most open motorcycles will never be able to travel faster than 250 mph.

Small differences in aerodynamic resistance can make a huge difference in energy utilized. An analysis of the racing profiles of Fignon and LeMond in the last stages of the '89 tour de France revealed that LeMond had 22% less drag than Fignon. The difference between the two riders? LeMond rode with a helmet and a Scott clip on an aero bar which allowed him to adopt a more aerodynamically favorable position with his elbows together. Fignon did not use a helmet or a Scott clip but he did have a front wheel disk instead of a wheel with spokes (Source).

In NASCAR races, aerodynamics not only make higher speeds possible but helps with cornering and stability. In order to go 200 mph, a car must have four times the power that it needs to go at 100 mph. The difference in the power required is almost entirely attributable to aerodynamic drag (Source.

Very little change in the profile of car can dramatically alter aerodynamic drag.
As illustrated in the figure, drag can be substantially reduced with only three changes: an air dam, side skirt, and roof rails. Note that when two cars run in line on a straightaway, both cars go faster than either alone. This is because the rear car raises the pressure on the rear of the front car. As pointed out by Dick Trickle, "Let's say I'm going 183 miles an hour by myself at Daytona. Now we get four cars hooked up -- now we've got four motors pushing and pulling the same air. We can run 189, 190..." mph. But interesting, two cars running side by side have to push extra air out and around, rsulting in a loss of speed.

So, there is your omnibus effect.

Wise.

[DA]

http://www.time4.com/time4/microsite...fuel_main.html

[rfbdorf]

Originally Posted by Wise Young

...the advantage of riding your bicycle behind another one that is breaking the wind

If the first rider is breaking wind, I'm out- you'll have to draft someone else to ride second place!
But yes, that's the same principle of decreasing the cross-sectional area.
Nice article, DA.
- Richard

[Wise Young]

Originally Posted by rfbdorf

If the first rider is breaking wind, I'm out- you'll have to draft someone else to ride second place!
But yes, that's the same principle of decreasing the cross-sectional area.
Nice article, DA.
- Richard

I find that quaint English expression, "breaking the wind", to be quite amusing. In Chinese, there is a single character 屁 for bowel gas, pronounced "pi". The combination of the characters 屁股 or pigu literally means fart drum or buttock. The word pi has many connotations, including nonsense. It is a noun and not used as a verb. When you say 放屁 or fangpi, it means to let out a fart. And when you say 屁话 or pì huà, it means fart language or nonsense. I was trying to think of the Chinese equivalent to "break the wind" would be 打风 which literally means is to strike the wind.

Excellent choice of words, to "draft" someone else. Isn't that what the process of slipping behind somebody's wind is called, drafting (Source)? It is interesting that drafting is penalized in triathlons (Source). One can also draft when swimming. A 2003 study (Source) suggests that the best distance for drafting is 50 cm from the toes if behind another swimmer or 50-100 cm behind the hands of another swimmer if 40 cm on side of the swimmer. The person's head would be approximately at the hip level of the leader. The reduction in metabolic rate is over 10%. I wish I had known this when I was swimming competitively in high school.

Wise.