Safely Storing Electricity

Pumped storage is generally recognized as the most practical and cheapest method of storing any significant quantity of grid electricity but the hazards of pumped storage sometimes go unrecognized. As Ontario’s power system proceeds down its current path of unbalanced reliance on inflexible generation sources we will see back-to-back shortages and surpluses of generation. There will be increasing pressure to develop storage to mitigate problems created by imprudent generation development.
Particularly those advocating more storage development for the Ontario power grid might benefit from studying the 2005 disaster at AmerenUE’s Taum Sauk Lake Hydroelectric Plant located about 140 kilometers south of St. Louis, Missouri.

At about 5 am on December 14, 2005, a breach in the dam impounding the 20 hectare elevated reservoir occurred after an automated system malfunctioned and pumped too much water into the reservoir. A backup system that should have caught the problem also apparently failed. With no overflow spillway to take the water, the water started to breach the dam. The ensuing erosion ripped a gap in the dam and 4 million m³ of water escaped in twelve minutes. Since this occurred during the winter, when the downhill campgrounds were fortunately closed, no deaths resulted although there were serious injuries to some local residents and massive property damage in the path of the flood that scoured the old growth forest to bedrock.
Any future pumped storage development in Ontario, particularly if constructed near people, should be required to be built to high safety standards, such as those employed in the replacement of the original Taum Sauk dam. The new dam is entirely constructed to roller-compacted concrete and includes a spillway, and improved monitoring systems.
Proposed plans for new Ontario facilities should be carefully reviewed by a public Environmental Assessment where affected people, particularly those living downstream, downhill and in close proximity, have due process rights for fulsome access to information and a review of their concerns by a qualified, independent authority required to issue decisions with reasons. As the Taum Sauk failure experience teaches us, any review process should also consider the safety of temporary visitors to the site and its environs.
Northland Power has proposed construction of a pumped storage facility near the town of Marmora in eastern Ontario. Northland proposes to develop an existing mine pit, formerly used to extract ore for steel smelting. The plan is to use the pit as the lower reservoir. To create the upper reservoir, Northland proposes to reshape the existing waste rock now piled around the pit, a technology similar to the original Taum Sauk pumped storage facility. The upper reservoir would be located uphill from the town.


  1. Tom,

    Thanks for noticing and commenting on the Northland Power pumped storage proposal in Marmora.

    There is a lot more to the story than just the “minimum required to do the job, (unless we can find a cheaper way to do it)” proposal for the reservoir construction. Our municipal government is spending thousands of tax dollars advertising and lobbying for a private company. Local government and our MPP continue to refer to the project as ‘renewable, which it obviously is not. Any system that draws more power from the grid than it produces, as the proposed pumped storage would, is a net consumer not a producer. The green energy act and other related acts clearly define “renewable sources of energy”, pumped storage does not qualify.

    The proposed pumped storage scheme could, at best, be justified as a load balancing/correcting service but even that function is questionable as it would take some minutes to bring the generator(s) up to speed and phase match before it could be placed on line. Load correction is normally accomplished with generators already connected to the grid running at speed and phase matched under no or minimal load and therefore able to instantly react to changing conditions.

    Apparently there is not any mechanism in place to license or connect the type of generation system proposed by Northland, our municipal tax dollars and my MPP’s time is being wasted chasing after a FIT contract for a facility that will never qualify.

    The Generator room would be cut into “solid?” rock at the lower level of the pit, the generators then fed though a pen stock from the reservoir approximately 600 Ft. above (at ground level)with the generator outflow (tail race) running into the bottom of the pit. Head pressure is a function of the difference between the upper and lower water levels. As the reservoir empties and the reservoir fills the head pressure will decrease and as the level of water in the pit increases the back pressure against the outflow will increase. Northland claims “up to 400MW for 4 hours” generating capability. As head pressure decreases and back pressure increases the 400MW capability would rapidly decrease.The simplistic assumption that reservoir capacity divided by required flow rate at a fixed head pressure will determine generator output will not work in this situation. Northland seems to think they are going to show profit from this. If they don’t generate as much power as advertised where is the profit coming from? Something just doesn’t seem right here.

    All of these issues (and more) have been pointed out to Northland power, the Municipal government and our MPP (both previous and the newly elected) yet the proposal is still being pushed by all the previously mentioned parties, which really begs the question, “why”?

    Thanks again for noticing our little local power scam.

    • If the Ontario government spills enough ratepayer dollars on this project, it could get built, notwithstanding its high costs. I wouldn’t assume that because the project does not fit within FIT that therefore nothing will happen. Economic efficiency is a foreign concept to McGuinty but changing the rules to make the latest fad fly is not.

      Using costly electricity storage to solve a problem caused by costly wind power is a special kind of insanity.

  2. I fully agree with the article and both Fred and Tom. We have a special problem in Marmora that goes along with that special kind of insanity, the “shirt bus” mentality that comes with a lack of foresight, no transparency and absolutely no personal responsibility.

    The tailings piles are not solid structures and therefore any earthquake of even mildly significant size, say a 5.0 to 6.0 within a radius of 150 miles could result in the collapse of the entire proposed upper reservoir. If it occurred anytime other than working hours, it could easily result in the deaths of more than 1000 people and hundreds of millions of dollars in property damage.

    During the mild 5.4 earthquake near the Ottawa River in 2009, some residents noticed that the tailing piles began to shed in minor landslides. Just imagine what the “tailing support structure” would do if it suddenly lost integrity with the weight of over 100 million cubic feet of water. Now imagine what would happen to possibly sleeping residents with all that water potentially rushing towards the town.

    There are two faults that produce or can produce earthquakes close enough to Marmora to cause a more than a serious catastrophe. One near the Ottawa River and the other near Darlington and Pickering. I have no idea what Ontario Hydro was thinking when they put two nuclear generating stations near one of the faults, but if it is any indication of methodologies, money trumps public safety every time. Just look at Fukishima, now we all not only have radioactive particles from Chernobyl in our bodies and the food chain, but we also have particles from Fukishima. And why, greed always trumps public safety.

    Using the Aecon pit via Northland Power in Marmora as a facilitator for pumped storage is dangerous. It is a project driven by greed rather than prudence. It flies in the face of common sense and it can only rationally be surmised that in order for this project to go forward that there are a lot of people on the payroll, both politicians and town council members whose limits of concern towards the safety of the town and its people, stops at their bank accounts. You may think that is a pretty bold statement, but I have seen it before, here and in other real countries (since after all, Canada is still a colony). Do I know what I am talking about, I’d like to think so since I have designed some critical sections of a few Ontario Hydro projects and have been performing engineering from both the private and public sector both her and overseas for more than 35 years.

    I do know without a doubt, that I will be moving any and all of my family out of Marmora before that reservoir is filled should this project go forward. I don’t want to be here if, no sorry I should say when, it the reservoir fails.

      • Yes, as far as I know the pit is owned by Aecon. They have also been doing the roadwork between Norwood and Havelock, I’ve seen their signs there anyway. Slowest bunch of wankers I’ve seen in a long time, talk about dragging a program out. If I were to take a video, I could drop the frame rate to 0.1 fr/sec and I might see some motion. If I was in the government I would have fired that lot ages ago. On the pumped storage, the battle continues, I expect I will have to organize a public meeting for “real time” very pointed questions and answers with Northland (if they would even show up, otherwise I can destroy their arguments without having to listen to BS). This pumped storage is one of those nasty greed driven situations (way too many of them thee days) that needs to be “torpedoed” in the harbour before the ship sails.

        One of the fallacies concerning this pumped storage project promoted by Northland is that this type of financial skimming program involves renewable energy. IN ITS PRESENT OR PROPOSED FORM IT DOES NOT INVOLVE ANY RENEWABLE ENERGY and any statement to the contrary is a lie. There is no way that this pumped storage system can either create its own energy or only use energy from “green” programs as the pool of energy comes from the power lines to pump water up the “hill.” An accounting entry saying the used energy is green does not make it true or a fact. This pumped storage program uses both the renewable apathy and the lack of research by the general population to work. I could use stronger words. The project is simply a skimming methodology that allows Northland power to make money by legally cheating electricity providers under the guise of legitimacy.

        There are many other ways of generating electricity and other storage methods which are far safer than having 27 billion gallons of water perched on a faulty rock pile 200 feet in the air behind a few hundred houses and businesses. We can’t forget the additional collateral damage this amount of water would cause surging down the Crowe River and Trent Canal all the way to Trenton, I have revised my damage estimates and expect that during a catastrophic failure loss of life could be upwards of 5000 people and property damage in the multiple billion dollar range. A liability bond might be a nice thing, a bit of insurance, but it doesn’t bring back the dead.

        Another thing to consider is that a pumped storage system such as the one proposed is a perfect terrorist target. Northland’s security will probably be limited to non-existent, it’s in a loose rural setting and the amount of explosives required to bring down the reservoir in say 10 minutes could be obtained easily. As I said above incredible amounts of damage could ensue. Oh, did I mention I worked for the military in national security infrastructure and military strategy? Hmmm, this scenario is just too simple.

        Of course these are only my opinions based on more than 35 years of experience in the field of engineering and research and development.

        • One more quick addition here, it has been brought to my attention that the actual size of the upper reservoir has been changed from what was originally calculated (27 billion gallons) to 4.1 million cubic meters (1.08 billion gallons). his new number is inline with the Taum Sauk reservoir and subsequent disaster. Pictures of the damage caused by the Taum Sauk reservoir breach can be found easily on the internet using conventional search engines. In the next couple of weeks we are going to perform a full volumetric analysis of the quarry, the existing inflow to the quarry from the aquifer (estimated at 770,000 gallons per day), the potential upper reservoir size requirements and any spillage outflow routing as well as Northland’s proposed flooding plane through natural wetlands (using the overflow chutes).

      • Dave is correct Barbara, Aecon does own the Mine site. They apparently acquired it as part of their purchase of another company. It seems to have been a case of having to take the less desirable parts along with the assets they were really after. Although they have been removing aggregate from the tailing piles I think the mine site is more a liability to Aecon than an asset. It is a large and dangerous area, attractive to the curious, adventure seekers and others prone to reckless self endangerment. The owners of such a source of potential lawsuits are required, in self defense, to fence, supervise and carry (probably quite expensive given the high risk)liability insurance.

        Northland power has an agreement to purchase the site from Aecon after they (Northland) have all the approvals, contracts and licenses they require to build, operate and make their opportunistic profits from the site.

        Apparently Aecon will also be the prime contractor for the project. Although we are only seeing the sales pitch from Northland Power I’m sure there is a lot of political pressure for this project to proceed being applied by Aecon. They want to divest themselves of this liability. (Check out Aecon’s web site to see who is on their board of directors, powerful influence and connections indeed.)

        Aecons involvement in the project also causes me to question the municipality’s (and Northland’s ) insistence that the project will create hundreds of jobs (up to 800 in one Northlands statement), with the unstated inference that a lot of those jobs would be filled by local residents. Aecon is a very large company with a large and established workforce that would move to this job as they do for any other. I’m sure, once the construction begins you would be able to find on site, Aecon workers who helped build the 407 toll Hwy., the Dragon boat breakwater in Toronto, worked on road repair and construction projects in the surrounding hundreds of miles and other Aecon construction projects. Of course, a few locals will be hired, temporarily, dollars will flow into the local economy for a few years, Tim’s will sell a lot more coffee, the local building stores will sell the odd can of paint and case of nails when Aecon is in a hurry and doesn’t want to wait for delivery from their preferred suppliers. Some of the workers may move into the area for the duration of construction, some houses will sell, any rental properties will be full, the gas stations will sell more fuel, the local trailer and RV parks, motels and bed and breakfasts will be full, temporarily. This is called a boom, which will be followed a few years later by the inevitable bust when construction is completed. Many will “make hay while the sun is shining” then leave. There will be little or no long term benefit to the community.

        Another pipe dream claim by some is that the project will be a tourist attraction. I suspect it will attract no more traffic than the Mine site does now. People pull off Hwy 7, look at the water in the big old man dug hole and the pile of rock that came out of it, read the info sign, get back out to the highway, stop at Tim’s for coffee and leave town.
        When the project is completed there will not be much more to see, everything to do with the pumped storage facility is hidden underground (except the 2 spill ways that will be cut through town to the river). There will still be just a hole in the ground with varying amounts of water in it, a big pile of barren rock and a sign to read. I doubt there will be tours into the deep underground generator site, no profit to be made doing that, just another potential liability.

        Marmora will not become a “destination” but will remain a quick stop for people just passing by on their way to real tourist attractions like Niagara, the parliament buildings or Wally World.

        • And now it is my turn for a small correction/update.
          After overlaying a recently released Hatch Engineering drawing onto a satellite picture it became clear that the spillways will not be cut through town. The spillways will dump into a wetland that borders the mine site (and the populated area of the town. The spillway water will then find it’s own way to the river through the naturally occurring lowlands.

  3. Apparently economic efficiency is equally a foreign concept to the PC’s, even with very realistic and well-founded safety concerns for life and property being added to the detrimental cost impact to the citizens of Marmora? News hot off the presses advertising the continuation of this special kind of insanity, is within the Legislative Assembly of Ontario Official Records for 21 February 2012:
    “106. Mr. Smith — Enquiry of the Ministry — Would the Minister of Energy explain why his Ministry has delayed in arriving at a FIT contract for the proposed Marmora Pumped Storage project. February 21, 2012.”

    Gee whiz, I wonder if the OPA is getting as sick of such seemingly endless displays of ignorance, spreading of misinformation and their being bullied, as the citizens of Marmora are? How often do politicians of every stripe at every level of government need to be not only told but offered hard proof that this pumped storage project not only poses a potential safety risk, is not defined as a “Renewable energy” project, is not eligible under FIT contract criteria, nor qualified under either Ministry approach requiring river flow for eligibility as a “Water Power” project?

    Memo to the PMO: You forgot to inform the citizens of Marmora that their individual rights to “security of the person” and remaining threads of “property rights” were the first (and only?) in Canada to have been “balanced” with the wider needs and interests of the provincial and municipal politicians now working for each other…

  4. Tom: Given that Northland Power’s own literature and statements refer to pumped storage “in general” as being comparable to their proposal, would you (or someone else) be able to provide data and analysis regarding this point made by Fred: “As the [upper] reservoir empties and the [lower] reservoir fills the head pressure will decrease and as the level of water in the pit increases the back pressure against the outflow will increase. Northland claims “up to 400MW for 4 hours” generating capability. As head pressure decreases and back pressure increases the 400MW capability would rapidly decrease.”?

    ie: What would be comparative construction and operation costs, generation output efficiency, profitability, etc, between existing pumped storage plants that drop the water used for electricity generation into an existing river or lake and those dropping into an enclosed space like Northlands’ proposed project would?

  5. Tom may have a better answer than I, Kathy, but Fred’s basic point — that the water pressure and electrical power are a direct function of the difference between the upper and lower water levels — is certainly correct. PS facilities that have a river as a lower “reservoir” would have the advantage of a relatively constant lower level, but the disadvantage that the lower level is higher, close to ground level. So for any given upper-reservoir height, dropping water from there into a mineshaft will generate more electricity. Put another way, to generate as much power as the mineshaft proposal, you’d have to build the upper reservoir (much) higher.
    All PS facilities would generate less power as the upper reservoir drains, but the “fade” should be much sharper in this proposal, because you’re losing “head” from both ends simultaneously.
    Most of us consumers already see red flags whenever we see a claim with “up to” in it, and the “up to 400MW for 4 hours” may well be another example of that kind of common puffery. (But I’m saying that without examining the numbers, documents, claims, or facts.) For sure, the MW capacity in the last part of the last hour will be much less than the MW capacity in the first part of the first hour.
    Of course, if this were a business project at the risk of private investors, selling into an open marketplace, all these issues would be covered by “due diligence”. It’s only when we’re talking about secret deals being negotiated behind closed doors with OPM (other people’s money) that we all have to become suspicious bloodhounds. . .

  6. NormRubin: The potential value of “independent” second (or more) opinion(s) may sometimes be underrated by folks offering such, but less frequently by those seeking such? If so, people local to Marmora other than just me may be grateful for your posted comments. I hope more comment exchanges will be posted here!

  7. I have a question raised by a Toronto Star article that was published last June. An article that seemed to be the reason for the signage around Marmora that was bought and paid for by the town council with our tax dollars. It seems that this article gives the impression that this pumped storage project would be of assistance in the event of a power outage in the province of Ontario, by providing power locally. I’m just not sure how?

    Apparently the generator needs the grid to start. How could it manage to produce power for any amount of time, let alone the five hours as suggested by the following excerpt from a Toronto Star article published June 29, 2011 titled “Mining for Megawatts in Marmora”:
    “And if there’s a massive power failure in Ontario, the reservoir at Marmora, about 50 kilometres east of Peterborough, would provide 400 megawatts of power for five hours to help get the system back up and running.”

    Somewhere along the way some of the people in Marmora seem to feel that this means they will have power when the rest of Ontario is in the dark. The generator apparently needs the grid to start and the power produced is fed directly back to the grid. There is no line directly to the town, as far as I know. How then would Marmora have power? Personally, I think it sounds like another misleading line fed out by Northland Power.

    • The pumped storage proposal for Marmora is not designed to deliver local power, but to send and receive from the province-wide grid. The Toronto Star article is accurately stating this case and should not be taken to mean that the neighbourhood will have the lights on in the event that the province does not.

      In the event of a province-wide blackout, the priority for service will not be local supply. During the 2003 blackout, the top priority of grid operators was to maintain power availability for the nuclear power stations to avoid an outcome that could have been like the Fukushima Daiichi problem. All other loads were far down on the priority list.

      • Although this was most unfortunately not clarified for the confused general public in either the Toronto Star article reference, nor by our local Council nor in any of Northland Power’s public presentations:

        Wouldn’t this “black start” capability of this pumped storage project be entirely dependent on its upper reservoir being already full whenever a province-wide blackout actually hit and took the grid down – since there assumedly would be no way this project’s upper reservoir could possibly be filled to provide this service in a timely fashion without electricity being supplied directly from the “working” provincial grid to this project to pump all that water up?

        IE what capacity would this project have to fulfill this service if a provincial blackout just happened to occur when the upper reservoir was partly, mostly or completely empty and what would the odds be that a blackout would be more likely to occur when the upper reservoir was completely full vs one of those alternative scenarios?

        Is there really general agreement among people “in the know”, with Northland Power’s inferences to the public and press local to Marmora that their upper reservoir would remain full as if on “standby” most of the time, until the system operator signalled them to empty it and start generating needed peak energy?

        People in Marmora who have actually studied every detail of this project intensely suspect they’d be constantly emptying/ refilling that upper reservoir to maximize their profits (along with the threat of overtopping and catastrophic flooding of nearby, lower-elevation homes, as the spring-fed lower reservoir sucks excess water in each time they draw its water levels down?)…who’s right??

        While thinking about that one, how likely does everyone “in the know” think it is that the Ministry of Energy/ the OPA will actually negotiate a longterm PPA with Northland Power, to operate that project as if on perpetual “stand by”, awaiting for the system operator to “signal” them to start generating electricity? Please let those of us here in Marmora know your opinion on the matters in this comment?!

  8. I too have noticed the prevailing “effects” of the local misconception Cindy mentioned. Perhaps folks too often don’t read past the headline and opening statements in articles, or research any further?

    One such article headline “Local mine may soon be powering the lights” (with webpage title displayed actually being “Local mine may soon be turning on the lights”), had an opening line that said: “The Marmora Mine could soon be producing enough power for up to 180 thousand homes.” You can read this here:

    Nobody ever asked or stated whether more than 180,000 homes could be powered by the amount of electricity this proposed plant would use to generate that amount.

    Unfortunately, the fact that more electricity would be used than produced by this proposed facility was “overlooked”. As was the fact that this project is not (as Tom agrees) designed to deliver local power.

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