Renewable Energy Is The Future

[Hersbird]

Originally Posted by aerohead

I watched a 24-part lecture series on energy from 'Great Courses',and the PhD doing the series said that most locals,which are sited to take advantage of hydro are already tapped.
And presently,as mountain glaciers melt away,Earth is losing more and more streams,rivers,and reservoirs for hydro.You ought to look at Hoover Dam right now from the air.It will break your heart.

Actually very few already damed reservoirs have hydro generators on the outlets. That would be a start. Then take something like the Mississippi and add dams and generators every 50 miles. Not to create a reservoir but just to tap that moving water. Move the barge traffic onto rails.

[redpoint5]

Originally Posted by Hersbird

Actually very few already damed reservoirs have hydro generators on the outlets. That would be a start. Then take something like the Mississippi and add dams and generators every 50 miles. Not to create a reservoir but just to tap that moving water. Move the barge traffic onto rails.

aerohead's point wasn't that there isn't room for growth in hyrdo power, only that it's relatively insignificant.

Specifically, this isn't true:

The potential energy of freshwater returning to the ocean would provide the whole world with a lifestyle of energy usage higher than what the US enjoys.

Hydropower is among the cheapest energy, so there's already huge incentive to tap those resources.



That graph is a bit misleading on its own because it shows electricity generation as a percentage of overall electricity generation. This shows overall generation:

[oil pan 4]

Originally Posted by aerohead

Wow! 1.4-billion Chinese,producing only double what 327-million Americans generate.No way we'll successfully compete against that.

I smell a free pass for communist chinese co2.

Pretty sad and so ironic seeing how most of the world's solar panels are made there.

[Hersbird]

I'm not going to buy hydro power is anywhere near fully tapped when so many rivers are free flowing. Wiki says the IEA report claims there is 75% undeveloped in North America and 82% undeveloped in Asia. So it's already the #1 renewable with less than 25% developed. Africa is basically untouched with 95% undeveloped. These are using current methods, and true using just those methods wouldn't rise to my claim of filling the future world's entire needs, but it could probably cover the current needs.

This is an interesting study on the total potential, but the final conclusion is only maybe 4-5 times "current" capacity is possible.
https://gigaom.com/2011/12/23/how-mu...gy-can-we-get/

[RedDevil]

I've been in the Eifel last summer, close to a large(ish) lake created by a dam.
However, large dams and lakes are pretty much the exception there. The Rur river is dammed every few kilometers downstream with just a few meters drop each time.

It is way cheaper to build a string of tiny dams than to build one big one, while the same amount of water flows over the same drop height. The river remains a river, more or less, and the land loss is minimal. The large lake upstream helps by regulating the flow to negate changes in the weather, so all dams can produce electricity fairly constantly.

[redpoint5]

Originally Posted by Hersbird

I'm not going to buy hydro power is anywhere near fully tapped when so many rivers are free flowing...

This is an interesting study on the total potential, but the final conclusion is only maybe 4-5 times "current" capacity is possible.
https://gigaom.com/2011/12/23/how-mu...gy-can-we-get/

Interesting link. It doesn't conclude that there is enough on the table to cover our energy needs though.

For technical feasibility, these same sources estimate 1.6–2.3 TW globally. Economic feasibility (in today’s economic climate) drops this to 1.0–1.4 TW. Environmental restrictions (in today’s climate) reduce this number further. Thus, having developed 0.4 TW worldwide (using average annual output for proper comparison to studies), the world may be able to expand by a factor of 2–5. This is a large range: a factor of two isn’t that much, while a factor of 5 is a pretty big jump. Where is it, really?

For the U.S., the Idaho National Laboratory estimates a gross potential of 0.3 TW, and a technical potential of 0.17 TW. The latter was determined after a study of 500,000 potential sites, out of which 130,000 made the cut. It is also estimated that existing dams with no hydroelectric capacity could add 0.013 TW (13 GW).

So here in the U.S., we could expand by a factor of 5 according to this report—ignoring economic and environmental barriers. Such a boost would bring hydro up to 5 percent of our gross energy, or 12 percent if we correct for the heat-engine effect (40 percent of our electricity). I have seen other reports less optimistic about our expansion potential, coming in closer to a doubling of current capacity —likely factoring in economic and environmental considerations, and consistent with the lower end of the range estimated for global potential...my mind is not much eased by the joint facts that it falls far short of our current demand

I learned that the #1, #2, and #4 highest generating dams in the US are all on the Columbia river. Everyone knows about Niagra and Hoover, but the Columbia river alone provides 40% of US hydropower. No wonder why our electricity is so cheap out here.

Don't know why everyone visits Hoover when it produces 1/3 the power as Grand Coulee. I might have to make a trip someday to look at it.

Anyhow, there is no electricity generation method that the extreme environmentalists accept, and since they are very noisy, somehow their complaints get an inordinate amount of media/public attention. They'd be happy to demolish a dam for the sake of fish without realizing that just means we'll be burning more fossil fuels to make up the difference.

I'm a big fan of hyrdo power. Back when HomePower magazine was in its prime, I read about micro hydro generation at home. When internet content got extensive enough, I found formulas online to calculate the generation potential of 2 sources on my parent's property. Sadly, my conclusion was that 75w wasn't worth the effort and change in landscape to implement micro hydro there. That amounts to about $65 in electricity per year.

[NeilBlanchard]

Large hydropower is not sustainable - the northwest US is a great example: the large loss of salmon is KILLING the forests in the river headlands. Without the dams, salmon reached their spawning waters, and when they die, they are eaten - and that was distributing a HUGE amount of nutrients onto the land.

This is no longer happening, and the rivers cannot survive this loss.

Also, the salmon cannot survive either - the hatchery salmon are in no way a replacement for naturally hatched salmon. They simply don't survive as well, and are very different.

The rivers themselves cannot survive - they silt up. The Three Gorges Dam in China in particular is a long term nightmare.

We can think about small / micro scale hydropower, though. If we collect rain on the roof of a building, the water can be used to generate electricity without disrupting the critical water cycle.

And, we need to develop all the different renewable energy sources:

https://thesolutionsproject.org/why-clean-energy/

There are 12 countries that are leaders in renewable energy: https://www.clickenergy.com.au/news-...ewable-energy/

[Hersbird]

The guy I referenced above has some other blogs about how no energy is sustainable at our growth, not even the entire power of the sun. In 2500 years we would need all the energy in the galaxy.

https://dothemath.ucsd.edu/2011/07/g...-scale-energy/

His point is the growth has to stop at some point, just on the physics of it. He then ties that to economic growth in another blog but I'm not convinced the two are 100% tied together.

[redpoint5]

That's my point about nothing in the universe being sustainable. It's a junk word used by hippies to signal superior virtue.

To use the word sustainable properly, you must define what we are attempting to maintain, and for what period of time.

Growth doesn't have to stop, but any particular rate of growth quickly gets out of hand. A decreasing rate of growth can mathematically go on to infinity.

[aerohead]

Originally Posted by Hersbird

Actually very few already damed reservoirs have hydro generators on the outlets. That would be a start. Then take something like the Mississippi and add dams and generators every 50 miles. Not to create a reservoir but just to tap that moving water. Move the barge traffic onto rails.

I believe that a majority of man-made reservoirs lack sufficient gravity potential for the hydraulic head,necessary to power a turbine-generator.Utilities installing pumped-hydro storage are currently forced to locate on top of existing hills/mountains,far above the turbine's elevation to get enough pressure differential across the turbine blades.Any fluid mechanics text would have the formulas for available power,given a specific elevation.It requires 32-feet of water column to develop an atmosphere of pressure (14.6 psi).Many hundreds of feet would be required to overcome a utility-scale generator.Edison used Niagara Falls,at 167-feet.The Oroville Dam is 770-feet.