Unaweep Canyon - hydro plant being proposed

Martin le Rouxwrote:

The Colorado Sun has a pretty good article about the proposal. See https://coloradosun.com/2022/05/22/unaweep-canyon-dam-hydropower-project/. Here are some quotes:   It can’t involve land managed by the Forest Service, which does not allow new utility-scale power plants. 

I wonder why that is.  I suspect they are confusing traditional hydro impacts, which used to be built by damming a valley.  Unlike projects like this which build small ponds below and on top of a large hill.   I have seen a map floating around on the internet that purports to show all the great pumped hydro locations.  It is quite faulty because it focuses on places to build traditional dams, which are not likely to be approved.  So that could be what the Forest Service is thinking of.    And that map fails to show simple locations that just require digging & lining the two ponds, with no huge riparian impact.  

tom donnellywrote:

That article says: " Pumped storage hydro facilities consume more energy than they create when they pump that water uphill. So it’s not a very efficient battery. "

Incorrect.  Large Pumped hydro is about 80% efficient, which is highly efficient.  90% in each direction.  Chemical batteries last less long and require large mines for the chemicals.

"The water would follow about 19 miles of new pipeline and it would take about a year to move 6,900 acre-feet into the reservoirs. About 45 days a year the wells would pump an annual 673 acre-feet to replenish water lost from evaporation on the two reservoirs. "

That amount of evaporation for this 140 acres of reservoir is tiny compared to a giant reservoir like Lake Powell, which is 160,000 acres, in a hotter climate, so it has about 1000 times as much evaporation.  Yet it generates about the same amount of power.  Glen Cyn Dam/Lake Powell generated 3000 KW-hr last year.  A 1 GW pumped hydro project can make 1 GW x 10 hrs/day x 365 days = 3650 GW-hr.  https://www.hcn.org/articles/south-water-powells-looming-power-problem    To stop wasting water with evaporation, focus on the real problem - giant reservoirs.

"It might not have a silt load from runoff but there will be a silt load, just ask any western slope pond owner. So much particulate is blown in with the spring winds that ponds must be pumped out regularly. "

Silt is not a big issue.  The outlet is slightly raised above a small volume used as a silt trap.  The ponds can be vacuumed/dredged like a large swimming pool once every 15 years.

"“This is rural Colorado footing the bill and making the sacrifices for urban consumers. "

Actually rural residents typically have a higher per capita carbon impact than urban residents.  And public land is for everyone, not just certain residents.

Here is a good example pumped hydro project in Washington state.  https://goldendaleenergystorage.com/project.html

You are making a number of incorrect statements.

For one, more energy is required to pump a volume of water up a pipe than is generated when it slides down the same pipe. We don’t live in a frictionless universe.

For another, Glen Canyon Dam generated 3 GWh, not “3,000 KW-hr” last year. (You’re off by a factor of 1,000.) The drawing-board calculations for Xcel’s proposed project come up with an annual “capacity” of 2.78 GWh. Would it ever operate at full capacity? I’m assuming that it will generate electricity only when solar and wind are not, which may be 35-40% of the time, so total annual generation could be around 1 GWh. Said “capacity” is just theory at this point, and could be rounded up to influence shareholders, rate payers, regulators, and the remaining public. As one of those rate payers, I would get to subsidize this project. 

George Bracksieckwrote:

You are making a number of incorrect statements.

For one, more energy is required to pump a volume of water up a pipe than is generated when it slides down the same pipe. We don’t live in a frictionless universe.

For another, Glen Canyon Dam generated 5 GWh last year. The drawing-board calculations for Xcel’s proposed project come up with an annual “capacity” of 2.78 GWh. Would it ever operate at full capacity? I’m assuming that it will generate electricity only when solar and wind are not, which may be 35-40% of the time, so total annual generation could be around 1 GBh. Said “capacity” is just theory at this point, and could be rounded up to influence shareholders, rate payers, regulators, and the remaining public. As one of those rate payers, I would get to subsidize this project. 

This isn't a dam.  It's not flooding a river valley.   It's a liquid battery that is charged from renewable energy and dispatched when renewables aren't available. Battery storage is a requirement if we're going to move off of fossil fuels so we stop cooking the planet. 

To provide storage to power things like hospitals, grocery stores and all the other things that we take for granted requires infrastructure. If we don't want infrastructure it means we live in the dark and drink warm beer. Power just doesn't miraculously happen to appear when you want to flip on the light switch.

The largest battery that we have in Colorado is only 4 MW with a 4 hour dispatch time.  This project would produce 800 MW for 8-10 hours on a nightly basis and doesn't require a shit ton of lithium or other mined materials.

 I would argue aridification and wildfire risks due to climate change are much bigger threats to Unaweep than this project which is trying to mitigate those things.

Not only is it not frictionless, moving power over power lines isnt efficient.

tom donnellywrote:

Those are different due to using traditional dams that have a large impact on a river valley.   Lower impact sites do not dam up an entire valley; they just have 2 manmade deep ponds.

I was referring strictly to the pumped storage/power generation aspect, not it's implementation.

Chris Michalowskiwrote:

This isn't a dam.  It's not flooding a river valley.   It's a liquid battery that is charged from renewable energy and dispatched when renewables aren't available. Battery storage is a requirement if we're going to move off of fossil fuels so we stop cooking the planet. 

To provide storage to power things like hospitals, grocery stores and all the other things that we take for granted requires infrastructure. If we don't want infrastructure it means we live in the dark and drink warm beer. Power just doesn't miraculously happen to appear when you want to flip on the light switch.

The largest battery that we have in Colorado is only 4 MW with a 4 hour dispatch time.  This project would produce 800 MW for 8-10 hours on a nightly basis and doesn't require a shit ton of lithium or other mined materials.

 I would argue aridification and wildfire risks due to climate change are much bigger threats to Unaweep than this project which is trying to mitigate those things.

Tom (incorrectly) made the comparison between generation by Glen Canyon Dam and pumped storage. In that regard, the Bureau of Reclamation website states that annual generation by GCD is 5 GWh. High Country News states that, last year, it was 3 GWh. Tom said “3,000 KW-hr,” which is 1,000 times less than 3 GWh.

I agree that global warming must be arrested immediately and that battery storage is important to augment solar and wind power. I agree that mining, manufacturing, and disposal of the materials required for chemical batteries are toxic. I think also that electricity usage can be reduced by society to a degree much greater than Xcel’s proposed project may generate.

Electricity generated by Hoover Dam/Lake Mead enabled Las Vegas to waste much of it on the Strip. GCD has been a part of the enabling of electricity waste in the Southwest. Most of the electricity generated by Xcel’s proposed project will also be wasted unless society changes its ways. The project could be unnecessary if we consume less electricity — and fossil fuel.

The is also true for water consumption. Denver and other Front Range cities have been diverting water from the Colorado River Basin for many decades. And more diversion is in the works. If those cities stopped wasting water on Kentucky bluegrass, as SoCal has been forced to do in recent years, more diversion would be unnecessary. 

My point comparing this type of pumped hydro to Glen Canyon is correct.  I corrected my typo above, which was obvious if you read the HCN article, which says "Last year, Glen Canyon was down to just 3,000 gigawatt hours."   So it generated about the same amount of power as a pumped hydro making 1 GW x 10 hrs/day  x 365 days per year  =  3650 GW-hr.  (1 GW is a nice round number).  Subtracting some since the pumped hydro won't be run 100%, would make them both roughly 3000 GW-hrs.    Even if the pumped hydro is only used to 25% of capacity, it would generate 1/3 of the recent power of Lake Powell,  Yet Lake Powell has 1000 times as much surface area, so the evaporation is about 1000 times as high, when full, and it's in a hotter climate.  Making its water loss somewhere around 350 times as high per GW-hr generated.  

And the pumped hydro ponds could be partly or mostly covered. governing.com/archive/gov-s…

Also many giant reservoirs like Lake Powell are getting so low in water that they may not be able to generate much power in the future.

Austin Donisanwrote:

Maybe you should spend 5 seconds looking at what the project is instead of making a competely unrelated comment?

Sorry. I was thinking in general terms. I feel the public appetite for any proposals with "hydro" is a non-starter. It doesn't matter how good the proposal is. I think people would be scared to try anything that use's water. Kind of the way I feel nuclear energy has got a bad reputation. People hear the word nuclear and they want nothing to do with it. 

Update - Xcel has pulled their application.

https://coloradosun.com/2022/11/02/xcel-energy-ends-plan-for-unaweep-canyon-hydropower-project/?mc_cid=aa6d8a6b06&mc_eid=f7007f4649

Great news!

Thanks for the update.

ErikaNWwrote:

Update - Xcel has pulled their application.

https://coloradosun.com/2022/11/02/xcel-energy-ends-plan-for-unaweep-canyon-hydropower-project/?mc_cid=aa6d8a6b06&mc_eid=f7007f4649

Because it was a bad idea, not for lack of pushing it forward nevertheless.

I went camping in Unaweep near the ruins in March of '76.

It was the only building in the canyon at the time.

Nobody drove through that night.

As far as I'm concerned Unaweep was ruined decades ago.

Ron Cloudwalkerwrote:

I went camping in Unaweep near the ruins in March of '76.

It was the only building in the canyon at the time.

Nobody drove through that night.

As far as I'm concerned Unaweep was ruined decades ago.

June 2021,

Went climbing all day in Uni. Never saw another party or heard a car drive by.

As far as I’m concerned Unaweep is still a great place. 

Unaweep is an awsome place. I'll never forget the first time I saw it and was amazed there was nobody there. At all.