Engineering is heading towards perpetual motion machines 2

[kacarrol]

Perhaps the writer of this newspaper article missed a key part of the plan to build this facility, but it sounds like they are going to try to get a net energy gain out of a closed loop system:

http://www.intelligencer.ca/ArticleDisplay.aspx?e=3167065

My step dad made a very good point on why they may want to go ahead with this. If they get a "green energy" incentive they may use energy from the grid to lift the water during off peak hours (cheaper electricity prices), then feed some energy back to the grid during on peak hours at the higher "green energy" price therefore netting a profit.

 

[SomptingGuy]

Pumped storage for demand peaks is nothing new and a really good use of disused mines.

The only bit of that article that disappointed me was the name "Hastings". Why can't these people think of new names for places?

- Steve

 

[kacarrol]

I probably should have worded that more clearly, here is the particular paragraph from the article that sounds off:

"The pumped storage facility would generate about 400 megawatts of electricity by allowing water to flow through a turbine system from the reservoir to the open-pit mine, and, vice-versa, use power generated by the down flow to pump the water back up to the reservoir to be reused and recycled through the system."

And they seem to be calling this a "green" project. While I understand that this helps the efficiency of fossil fuel plants etc to help them run at a more constant rate, it's my understanding that storage facilities still work at a loss of 20-25% (they are 75-80% efficient). Maybe I'm missing something about the definition of "green technology"?

 

[TheBlacksmith]

There is definitely a net loss in this system, as neither the pumping or generating is 100% efficient. However, as pointed out, it can allow the existing plants to be more constantly loaded and more efficient and is an excellent way to peak shave within building another fossil fueled plant.

 

[MintJulep]

75 - 80% efficient?

From fundamentals it should be obvious that pumped storage must operate at a negative efficiency.

It sort of makes sense where there is an over supply of electricity produced by big thermal plants that can't be turned on and off at the flick of a switch, or can't be turned down at off-peak times without serious repercussions on efficiency or emissions.

They are "green" because the term has no meaning, and people don't understand how pumped storage works within a larger system.

 

[KENAT]

OK yeah, the line you high light sounds a bit off. Even if they meant net power (shouldn't it be energy?) put into the network what is returned later to pump the water back up then there's still a big efficiency loss they ignore.

Pump store is very useful for peak shaving etc. and as such can help with the overall efficiency and even 'greenness' of the electrical network. While they do tend to pump the water up when there is surplus power, I don't think that's how they'd make their money as such.

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[zelgar]

I wonder if they've considered the following:
Evaporation loss vs Precipitation Recharge
Potential contamination of water due to leachating of minerals in mine

 

[CastMetal]

Is this style of Pumped storage more efficient/economic than above ground reservoirs? I would imagine it is much easier to overcome environmental hurdles by using disused mine shafts but do the technical difficulties incurred by operating underground outweigh the political benefits?

Comprehension is not understanding. Understanding is not wisdom. And it is wisdom that gives us the ability to apply what we know, to our real world situations

 

[zelgar]

Based upon this statement: "Mantenuto explained Northland plans to build a massive water reservoir above the mine utilizing more than 70 million tons of rock already present at the site." they're using an above ground reservoir.

 

[KENAT]

"700-foot deep open-pit Marmora mine"

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[ornerynorsk]

Pesky laws of physics, ruins everything.

These guys must be coming out of the woodwork lately, green flavor of the day, one would suppose. I looked at a project down by Houston a year ago that purports to do nearly the same thing, only using wave action in holding ponds.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[btrueblood]

It looked to me (trying to read between the lines of journalism school dropout lingo) like the pit was to become the lower reservoir, and a second, upper reservoir was to be constructed using on-hand tailings as ballast.

Using tailings for ballast (dam walls) may be a surface-water contamination issue, depending on how well/reliably it gets sealed. Can't really see how the pit being filled with water would be any more of a groundwater contamination issue than it already is.

 

[kacarrol]

I believe this is the old Deloro mine site, and has a particularly nasty background with regards to pollution:

http://news.ontario.ca/ene/en/2010/11/cleaning-up-the-deloro-mine-site-in-marmora.html

 

[GregLocock]

So we've moved on from perpetual motion to contamination. Agenda much?

http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

Cheers

Greg Locock


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[hokie66]

The efficiency of the hydro part is negative, but that doesn't matter. The hydro storage makes the entire generating system more effective. Works a treat when combined with a continuously running nuclear plant.

 

[mendinho]

A similar mixture of wind and water will soon be providing an abundant supply of energy for the 11,000 inhabitants of El Hierro (Canary Islands, Spain). In 2000 Unesco made the island a biosphere reserve. This meant that the wind farm had to meet strict requirements: the site is exposed to the prevailing wind but well out of sight, and all the pipes and buildings were either painted camouflage green or buried.

http://www.storiesproject.eu/docs/El_Hierro_Project_-_Estoril_26.03.2010_G._Piernavieja.pdf

http://notonlybridges.blogspot.com/2009/08/wind-water-power-perfect-match.html

http://NotOnlyBridges.blogspot.com

 

[TheTick]

All well and good so long as UNESCO buys the green paint and pitches in with the shovelling.

 

[photoengineer]

I'm seeing a lot of interest in attaching wind turbines to the output of air conditioning vents to capture otherwise wasted energy.

It's a cool idea, but the idea of harvesting energy from an electric motor is one of the types of a perpetual motion machine.

 

[SnTMan]

Its only PM if you use the wind turbine to run the air conditioner to run the wind turbine to run the...

 

[MortenA]

I actually think that Kacarrol opens a very urgent question. An abondonned mine may still contain a lot of heavy elements, arsenic and other contaminants.

Best regards

Morten