This Device Could Provide a Third of America's Power | Hacker News Reader

This Device Could Provide a Third of America's Power

bloomberg.com

56 pointselectic44 comments

David MacKay's "Sustainable Energy - without the hot air" [1] does a good job of putting energy sources like this in perspective. Wave energy is indeed challenged by issues with mechanical parts; however, the reality is that there isn't much wave energy their to begin with. As MacKay puts it, "sun makes wind and wind makes waves" [2]. Waves are just diluted sunshine. Sandia National Labs does a good job of putting this into perspective, assessing solar electricity with a theoretical potential of 89,000 TW and ocean wave with 34 TW [3].

We could try to make the case that, despite the small potential, wave power is convenient to extract. We do this for hydropower, for example. However, where there are waves, there is wind. On cost and reliability, I don't see wave power ever being able to beat out offshore wind.

1. http://www.withouthotair.com/

2. http://www.withouthotair.com/c12/page_73.shtml

3. http://www.sandia.gov/~jytsao/Solar%20FAQs.pdf

Wind generators and some aspects of solar cells use rare earth metals. The big advance of this particular company is not using rare earth magnets.

Not sure that is true, the large generators don't use permanent magnets. Old school generators used a small DC motor with permanent magnets to power the field windings. However I think the generators in large wind turbines use an inverter to proved power to the field windings. (So that they can account for small mismatches between the line frequency and shaft speed)

If we were to do this on a large scale, how would it impact the waves we are seeing? Might that impact coastal wildlife? Might it even impact currents and weather patterns?

Some of the impacts are covered here: https://en.wikipedia.org/w/index.php?title=Wave_power&sectio...

If done on the scale suggested in the article, it would be catastrophic; article infers that the whole ocean should be used as a source of engery, which is madness.

It would, but you are really asking if the impact would be noticeable. A single hurricane can be releasing ~1/2 global electric generation, which at least suggests that installing a bunch and observing the effects will be a safe enough strategy.

Are they saying it could provide a third of America's power (I'm guessing current electricity consumption) from America's coastal waters, or from the whole of the world's oceans?

The former, including your guess. They clearly say so in the video.

Wow. I literally didn't notice there was a video. Everything clickable just looks like an ad to me now

During the video they said 1/3 of America's energy requirements from America's coasts.

We don't need super-solutions/magic bullets for electric generation. Tidal could fill in where its best suited, such as Newfoundland. Imagine if we had:

20% Nuclear (been this for decades)

25% Natural Gas (27% now)

23% Wind (4% now)

22% Solar (1/2% now)

5% Tidal (none now)

5% Hydro (6%-7% for decades)

and no coal at all. (35%-50% for decades)

We kitesurf in a river mouth, the river is tidal. Behind the beach are a couple of pools that are huge, these get filled and emptied by the tide twice a day. The volume of water that slooshes out is amazing. Staggering. We love to kite there cos we convert the energy into speed.

I am personally excited about tidal as it is almost completely predictable. The wind may die down and clouds may block the sun, but the tide always comes in on schedule.

How do these things stay on station? I live near the Gulf of Maine. When we have an ocean storm, the lobster buoys and sometimes the navigation buoys end up on the beach and have to be put back where they go. Other times they end just lost in the ocean.

Sometimes divers have to go find the lobster pots. Pots that can't be pulled are very wasteful.

Putting these generator things back might be quite costly. It will certainly create jobs for commercial divers.

How do they keep the cables (surface to that big old tire thingy hanging in the water) from getting tangled or broken in storms? That U. Maine wave tank should be able to help them figure it out; its purpose is storm simulation.

How do they get their power to a shore-based distribution point?

This is a magnetostrictive generator. It's not "no moving parts", it's flexures instead of rotational joints. Historically, magnetostriction was a weak effect, but some new materials have improved the efficiency.[1] Still, operating at the ocean surface is usually a high-maintenance headache.

A no-moving-parts solution would be taking power from an ocean current by using it as the working fluid in a magnetohydrodynamic generator. That's a totally submerged system. The concept has been used in reverse to drive a ship, so this can work in seawater.[2] But it requires superconducting magnets, and all the cryogenics which go with that. If we ever get room temperature superconductors, this might be useful.

[1] http://revolution-green.com/magnetic-energy-harvesting-using... [2] https://en.wikipedia.org/wiki/Yamato_1

Here's a more detailed article about the device from The Economist: http://www.economist.com/news/science-and-technology/2167761...

The UK's Witt Energy device can be used in marine and wave power applications - and can harness kinetic motion in all six degrees - using pendulums. See https://news.ycombinator.com/item?id=11514839

Those devices are impressive and they probably work, but as the video correctly stated, the maintenance of those devices are the problem and makes them cost prohibitive. Typically, devices with moving parts have a shorter shelf-life, because of the hostile ocean environment.

Magnetostriction is news now? See: https://en.wikipedia.org/wiki/Magnetostriction

They're doing it without high price rare earth magnets.

...could provide a third of America's present power requirements.

U.S. energy demand has actually fairly steady. It was slightly lower in 2014 vs 2008. http://www.indexmundi.com/g/g.aspx?c=us&v=81

A wide range of things have been getting more energy efficient TV, lighting, computers, heating cooling, insulation, etc.

Does this account for things beyond electricity such as fossil fuels?

For example, the shift from using gasoline cars to electric cars would reduce the amount of electricity we use, but would increase the amount of gas. This could be a net good, if we assume that the electricity was produced in a cleaner way.

I think you mean increase electricity and reduce gas?

It's good things are getting efficient up to a point however those kind of savings are unsustainable and in the longterm our energy use will continue to grow exponentially, including for environmental management. Thus it doesn't make sense to research power sources that aren't potentially 100s of times greater than our current usage.

"For my future life of luxury I will have to find a lot of gold so I'm not gonna plant potatoes today."

Boring, pointless potatoes.

That's a false analogy since farming potatoes is an existing technology.

You advocated forgoing research in a proven field for research in speculative fields. The analogy is about favoring prospecting over farming. In farming you can calculate an expected yield, in prospecting you don't know what you are going to find.

Every time I see a good article on sustainable energy I tweet it to Elon Musk.

>> "That's 352,670,000,000,000,000,000 gallons just sloshing around out there."

^^ Stopped reading after this sentence.

>> Stopped reading

Stopped caring after seeing that

Your right, trying to exploit in an entire ecosystem for the benefit of a single species is a great idea.

That's literally what every species on the planet is trying to do, as well as they can.

All species self-regulate. If you feel you're able to provide notable research countering this, please do; happy to admit I'm wrong.

https://www.google.com/search?q=species+self-regulation

All species self-regulate.

https://en.wikipedia.org/wiki/St._Matthew_Island#Mammals

Also really fun comic about this: http://www.stuartmcmillen.com/comics_en/st-matthew-island/

happy to admit I'm wrong.

There you go.

Now before you start blaming developed nations about their energy usage, it is good to review the data persented here: http://visualizingeconomics.com/blog/2007/12/09/comparing-po...

Here's an example of notable research, "Why most published research findings are false" - note that it's been cited over 3000 times: https://scholar.google.com/scholar?cluster=15681017780418799...

In my opinion, the event you references is not notable research.

I do not know where you live, so your exposure to the actual wilderness might be limited, but if you had any real exposure, you would know that without big predators (like wolves in the northern part of the world) or hunting, the herbivores would bread to use all the available resources they can get.

Yes, ecosystems (that is, set of different species including plants) self regulate themselves, but species try to maximize their numbers. If their numbers get too big, they starve and by some unlucky coincidences, they my become extinct due to resource exhaustion.

I actually hope that humans would be better in this.

The first page of results* from your own recommended search will provide you an answer: ecosystems self-regulate. Animals starve. It's not quite the same thing as the wise and forward-looking animals of the forest that you appear to be arguing for.

*I realize that my first page might not be your first page - perhaps based on our differing search histories.

Yes, I'm aware of that search result, and for the matter the concept; sometimes being direct is less useful than being indirect.

Expecting all animals to be wise in my opinion is unreasonable, I would hope that some animals are able to be reasonable.

Cyanobacteria is the only animal I am aware of (beyond homosapiens) that has been responsible for a significant extincion event on Earth.

Cyanobacteria was just lucky. Give the deer a change and it would put everything out of this planet including themselves.

Luckily for us, this stupid animal can only flourish under very limited conditions.

This is an excellent example: "the residents of Long Island on Lake Winnipesaukee wanted to eliminate hunting deer so they could enjoy these beautiful animals. A few years later, the deer had eaten all the wild shrubs and trees, and began invading the homeowners' property on the island to sample the flowers and shrubs of the residents.". [0]*

[0] http://www.seacoastonline.com/article/20140407/SPORTS/404070...

* remind you, I am not advocating of killing off all the deer because how else will the big predators get enough of food and how else we can get all the tasty deer meat sausages.

Very possible you'd learn something by reading this: http://www.all-creatures.org/articles/act-c-sh-mythreality.h...

While the link I posted was clearly a propaganda of one side, it consisted at least few facts. This one seems to contain only opinions.

I agree with one of them, killing other species should not be regarded as sport.

Edit: For more balanced opinion: http://www.koryoswrites.com/nonfiction/white-tailed-deer-ove...

Edit2: The site listed above is actually full of fascinating animal behaviour.

Facts in that story are factually wrong: http://www.deerfriendly.com/decline-of-deer-populations

I think that people from Deer Friendly intentionally manipulate with the data visualization. They smooth the graph elsewhere and only show the population plummeting when it satisfies their agenda.

For example the graph here about NY looks more honest [0].

Also I am not fully convinced about their argument related to the sampling methods. [0] seems to be again more honest in this case.

Also they do not mention increasing numbers of feral hogs that hunt the deer fawn as a predatory balancing factor to the possible cause of deer number decline.

This still does not mean that deer do not cause damage to the other species and biodiversity and that they do not increase their numbers over the resource exhaustion which were the the main claims of [1].

Anyway, the deer example was a counter example to the claim that "all species self-regulate".

Even more generally, in their niche they are a fine example of "trying to exploit in an entire ecosystem for the benefit of a single species". They do not live in harmony with diverse range of other species in their habitat.

[0] http://hvfarmscape.org/mammals

[1] http://www.koryoswrites.com/nonfiction/white-tailed-deer-ove...

Reply on news.ycombinator.com