Guest Post by Willis Eschenbach
I grew up on a remote cattle ranch in the middle of miles of forest in the northern Sierra Nevada mountains of California. We had our own hydroelectric power plant. It was built by my father and my brother-in-law. They put a two-foot high dam across the creek (blue line), and diverted the water into a mile of ditch that they dug from there to a lake that they built by the house.
Figure 1. Renewable energy, circa 1952
Then they built a penstock and dropped part of the water back to a powerhouse by the creek. Inside the powerhouse was a Pelton Wheel that drove an alternator. Poles carried the power (4,000 volt, 10 kilowatts) to the ranchhouse. That was the only power for the ranch, and there was only us to keep it running. That was my introduction to renewable energy.
When I was a kid, our grade school took a field trip and toured Shasta Dam, in Northern California. I was astounded by it. I loved the idea that it was just a bigger version of our little powerplant.
Figure 2. Shasta Dam, Northern California. Note the five large penstocks at the lower left leading to the powerhouse. MORE PHOTOS
These days, of course, it is almost impossible to build a small dam in the US, much less something on the scale of Shasta Dam. People raise hundreds of objections, any project is stalled before it starts. This has always seemed extremely foolish to me, since hydroelectric power is proven, 24-hour, baseline power. Despite that, there’s a whole branch of the environmental movement that considers dams as forces of evil.
Which is why I laughed out loud when I saw the latest numbers on the CDM. The CDM is the “Clean Development Mechanism” of the Kyoto Protocol. The CDM is the foundation of the carbon emission credit system in use in Europe. Companies which emit more CO2 than the regulations allow can purchase credits. The companies pay the money to sponsor an emissions-reducing project in a developing country, so in theory everything balances out.
There’s a New York Times article on the CDM here. This is the part that I found to be hilarious (emphasis mine):
Since it began operating in 2006, the board has validated 2,918 projects, 40 percent of them in China, according to the U.N. Environment Program’s database at the Risoe Center, in Denmark, which tracks every project in the C.D.M. pipeline. The center’s data show that 1,668 projects are in hydroelectric power and 1,060 of those are in China.
So the effect of the Kyoto Protocol is that it is OK for the West to burn fossil fuels, as long as the West is also subsidizing hydroelectric dam construction in China …
Does anyone but me find that truly and bizarrely hilarious? I’m sure the Chinese are busting up laughing, and saying “Give us 20 Kyoto protocols, this is great, we’ll let you well-meaning Western fools build all the hydroelectric plants China can hold” …
polistra says:
October 14, 2010 at 3:08 pm
While that is somewhat true for conventional hydro, there is still a huge resource of mini, micron, and nano hydro. In addition, we are just starting to build turbines to run off the energy of the flowing river. So no, the day of new hydro is far from over.
Finally, there are a number of good sites which are not economical because of transmission costs. Obviously, this may change in the future, as new transmission technologies come online and people move closer to the sites.
Ike, I wish you were right, but the number of players for whom “environmentalism” is about “power and money”, is small, if influential. It would lack all influence, however were it not for the fellow travellers for whom it’s all about punishing western civilisation for being so successful and benign.
Just as long as you know you’re joking, good one.
Sorry Tenuc, but you are mistaken. “Freely moving tons of water around” is largely a conversion to and from kinetic and potential energy. When the water piles up at high tide, the system energy is potential energy, and when it is rapidly flowing in or out, it is kinetic energy. Only the frictional losses (viscosity, flow against rocks, etc.) represent lost energy. Increasing the frictional losses, which is what tidal power does, drains additional energy from the system. This is very basic physics: increase frictional forces and you increase energy loss. But besides, if you were correct, then the only energy that could be removed would be the energy currently being lost by the tides, which is only half the 1970s energy usage of mankind. That would make it a largely useless idea anyway.
This article:
http://www.science20.com/chatter_box/pushing_moon_away_victorian_machinery quotes a figure of 3 Terawatts natural tidal frictional losses per year, and gives the USA’s 2002 usage as 3.3 Terawatts.
Then this is your lucky day! You get a chance to actually prove it for yourself, which is the most valuable kind of knowledge you can have, by doing the calculations, just as I did. All you need is something on the level of grade 9 maths to solve the relevant equations.
Look up the formula for the moment of inertia of a sphere (approximating the Earth by a sphere), plug in the Earth’s mass and radius. If that is not accurate enough for you, then represent the Earth by concentric hollow shells and put in the actual measured densities for the Earth at the various appropriate depths. But to see the basic idea and since a precise answer isn’t necessary, that latter step is probably overkill. But one way or another or by looking up the net, get yourself a figure for the Earth’s moment of inertia – call this “I”.
Now you need the formula for rotational kinetic energy:
Krot = 0.5 * I * w * w
where w is the angular speed.
And you need the angular momentum, which is:
L = I * w
Now you need to add up all the rotational kinetic energy. For simplicity ignore the orbital Krot of the Earth around the Moon and only consider the Krot of the Earth’s rotation (calculate as above) and add the Krot of the Moon’s orbital motion around the Earth; for this, use I = m * R * R, where m is the Moon’s mass and R is the Earth-Moon distance.
The total Krot in this sum is the value that is reduced by drawing energy from the tides.
Now for the momentum equations, the angular momentum L = I * w, with the same I and w as above. Add up the angular momenta of the Earth’s rotation and the orbit of the Moon around the Earth. This formula represents a conserved quantity that cannot be changed.
That means that if you change any quantities in the total Krot formula that you now have, you must do so in a way that conserves the result of the total L formula which you also have.
You will find that the way the conservation has to work is as follows: If an amount of energy E is removed from the Krot formula, then it has to be done as follows: 2*E must be removed from the Earth’s rotation component, and E has to be added to the Moon’s orbital component. Nothing else will balance the L equation.
As for the “dooming us all”: there are lots of things we don’t know about the Earth” Why does Earth have continental drift, which is a heat release mechanism, and Venus doesn’t? Venus builds up heat within and occasionally it all bursts forth and churns over the entire crust in one huge volcanic episode; even if Venus had a habitable temperature, that would put paid to life anyway every 500 million years or so. Does the Earth’s continental drift depend on the lubricating effects of the Moon’s tidal squishing? I don’t know if anyone knows. Perhaps we are just a hair’s breadth away from having continental drift suddenly stop? Maybe we are at a TIPPING POINT!!!!!! Do you know? I don’t. The damage from weakening the tides and lengthening the day are largely unknown, so why play with it?
I am concerned about the next glacial, in which, were it not for human emissions of CO2, the CO2 content of the atmosphere would be in danger of falling below the critical value necessary to sustain plant life, thus causing the end to most life on Earth. And to answer your question, I have given you all the formulae you need to get the answer just up above.
Nothing much in this world is truly original, but I have indeed done the calculations for myself as explained above. This sort of thing is a typical student’s exercise in physics courses.
Hydro power is great, provided there is an area for water storage and sufficient head is available to drive the turbine. Mountainous areas provide the best places and should provide sufficient snow melt and rain to maintain the water supply.
Claude Harvey,
What a waste…
Never trying to harvest the energy into individual molecules.
Doing the brain dead robot…follow the leader thing.
Use your head.
Turbines were created for bulk harvest and NOT efficiency.
If I was that stupid, why was I invited before a board of directors of a major hydro-electric company? Why would a secratariat at the UN for energy give me the time of day?
Engineers can ONLY tell if the mechanics are sound and nothing else. The science is beyond their field…says an engineer at a college that advanced technology was shown.
Hello. My name is Albert. I am from Armenia. If somebody wants sponsoring to built hydro power plant I have all documents and license for it. If you interested in my suggestion,please, write on my mail, I`ll answer. Thank you.
Hello. My name is Albert. I am from Armenia. If somebody wants sponsoring to built hydro power plant I have all documents and license for it. If you interested in my suggestion,please, write on my mail, I`ll answer. Thank you. albertpetrosyans@gmail.com
There was an old saying once, “Ignorance of the law is no excuse.” Today, of course, it’s a basic basis for pleading innocent. Anyway, if I wanted to build what you and your family had way back then in the middle ages, you mean I gotta ask someone for permission? And they’ll probably say I can’t? And they don’t have to live next door, but anywhere they wanted to, and they can still say no? Hmuuum….. that does change the color of the grapes doesn’t it? You know folks, history seems to support a complete re-write of every law on the books about every 250-500 years. Of course, the chances for a civil war or two seems to crop up more frequently. I’ll bet it’s the air. Something in the air. Let’s see… 1776…. 1861…
@Rich Borba says:
How about we call the environmentalists what they really are, a religion, and then follow the constitution in making no laws respecting religion.