Cool New Idea in Wind Turbines
Here’s a new idea in the quest to reduce or remove the variability of wind energy: an integrated water reservoir, making use of the huge watertight tower. This creates a (small) pumped hydro energy storage solution without the elevation change. Obviously, we need to replace the evaporating water, but this does appear potentially cost-effective nonetheless. Good thinking, IMO.
I doubt that using water towers for pumped storage would be practical. The amount of water that would need to be stored would make water towers too expensive. However, pumped storage is very practical when geography coöperates.
Because of the huge water requirements to have sufficient storage, huge reservoirs would be required. That problem can be solved in mountainous areas where reservoirs can be created with dams. And, because the wind can be insufficient for weeks at a time, the reservoirs would have to be huge.
The amount of energy storage necessary to get reliable power from intermittent sources is often hugely underestimated.
This doesn’t seem to make any sense so I looked at the cite and I am still at a loss. The 4 wind turbines are sited on the top of a mountain. There is a pipe running between each of the tanks and a pumped hydro station in the valley.
That seems like an awful lot of piping that is just going to increase resistance losses. The piping between turbines likely adds nothing to the system. The wind turbines are not being used to pump water, just provide electricity.
I can’t see in this design anything different than a pumped hydro station using tanks on a mountain top and a series of separate wind turbines.
So why not just site one large tank at the top of the mountain and have the shortest possible pipe to the hydro station in the valley.
Perhaps something is missing from the description.
Re Frank’s point. The scale of storage needed depends what you are trying to do. If you want a stand alone system based only on wind and pumped hydro, yes it does need to be huge. If you want merely to facilitate integration of a larger wind farm than might otherwise be practical, a few hours of storage can be very useful as a buffer to help keep the grid stable.
I have thought for a long time that pumped storage should be integrated into the mountain tops in West Virginia where they are removing the mountain top to get at the coal. The debris from removing the mountain top is already thrown down the side of the mountain. The main complaint in this is that the debris pollutes the water supply in the valleys below that the populations relies on. Use that debris to make a holding pool at the bottom. Leave the mountain top as a bowl for holding water when the coal is removed. Ring the top of the mountain around the bowl with turbines which puts them up there where the wind is. Run a pipe down the side of the mountain to a pump/generator at the bottom. They are doing at least half the work just getting at the coal anyway. Why not take maximum advantage of it?
Brian I read today of exactly this process being contemplated for a hydro storage facility in Scotland or Canada, sorry I can’t recall the cite.
I was a bit disappointed as it seemed that they were removing and selling the coal as a way “to help defray the cost of the facility.” It was a reminder that although I look at the article with an eye on the clean and renewable aspect someone remains concerned about the bottom line.
Very dangerous – coal slurry heaps and water make a very unstable mix which can fail suddenly and catastrophically. In the UK we have just remembered the 50th anniversary of the Aberfan disaster in Wales when 144 people including 116 children in the local school lost their lives to a landslide of coal waste, which to start with, was piled far too high, but which became deadly due to the presence of a spring below the slurry heap.
I would say the difference here is that these holding pools will already be at a low elevation, will not be built up for 50 years and cement could be used to insure a viable and stable structure in accordance with proper building techniques. The debris would be aggregate in the concrete.
New methods to Expand the use of Wind and store energy for peak load times during the late afternoons etc.
The water concept has merit in areas with the water or Mtn tops for a pumped hydro situation. But as others state has high cost and the usage of water etc. Don’t like the linkage with coal .
Perhaps a better one is what Siemens Corp is doing field testing in Germany right now. They are building large tanks with Molten Salt similar to solar CSP plants and they will store heat for later usage and mate it to a turbine to make peak load electricity.
The field demos should be done in 2 years or so.
This is very doable and should be economically competitive and demonstrate another generation method that expands the usage of wind power. Another Nail in the Coffin for Big Base load plants take your pick no need for those big coal or nukes like in days past.
Other technologies like compressed air storage and this water concept all are limited to specific geographical locations.
Molten Salt looks promising in comparison.
The answer Indeed is Blowing with the Wind
If efficiency is even a very remote consideration, I do not see how converting either electrical power or motion into heat then later converting the stored heat into electricity as practical.
Electricity can efficiently converted into heat and recovered where heat is the desired form of energy, such as for process heat or heating buildings. Motion can also efficiently be converted into heat and stored. But converting heat energy into anything else has a very high efficiency loss. The efficiency is unlikely even to approach 50%.
The most efficient way to convert heat into electricity is with a heat engine, probably a turbine (which is what Siemens is said to be using), driving a generator. But the efficiency with which heat can be converted into motion would depend on the temperature of the stored heat. The higher the temperature, the higher the efficiency. With a bit of google searching, the formula for the maximum possible efficiency can easily be found, but in practice, that maximum possible efficiency would never be attained. The maximum possible efficiency would be with a Carnot engine which, unfortunately, is impossible to make.
So yes, the concept is doable, if you don’t mind recovering about 30% of the stored energy and wasting about 70% of it. And it seems highly unlikely that Siemens has found a way to circumvent the laws of physics.
Frank Isentropic PHES uses heat to store electricity. It is projected to be as efficient as pumped hydro, about 70%. The cost is not presently not clear. https://www.youtube.com/watch?v=sIxt6nMf-IQ Perhaps your estimate of the energy losses with heat storage might need to be tweaked a bit.
Here is a pilot project trying to create a grid level demonstrator plant https://ec.europa.eu/inea/sites/inea/files/smallbone-swan-centre-phes.pdf
Breath,
It is still unclear that Isentropic PHES will actually meet the expectations of the developer. In looking around, one finds that there is considerable skepticism from multiple sources.
My major objection to assuming that intermittent power sources have a major rôle to play in migrating from fossil fuels is that there are entirely too many undemonstrated assumptions. I greatly fear that the extreme reliance being placed on intermittent sources of power will considerably delay our migrating to an energy system which will work thereby resulting in additional global warming to the detriment of civilization as we know it. Then, when it is found that intermittent sources of power cannot do the job, those who supported intermittent sources of power will say, “Well, we thought it would work. We honestly did. How could we have known that it was not up to the task?”.
Frank, I am aware of your reservations regarding “unproven” technologies. This is why I took the initiative to try and locate a test of PHES technology. From the cite above you can see that a grid level test project is planned. I expect that it is looking for funding.
What does this mean? While the literature is not clear it seems that calculations have been made and theoretical estimates of efficiency have been demonstrated.
A grid demonstration project should further prove any estimates and assumptions were accurate or simply wild guesses. Such a project should further clarify economic expenditures and allow more accurate estimates for a facility with larger capacity. While the results could vary I would consider this a fairly narrow list of expectations for a demonstration project. I would be interested in viewing any cite that was critical of the technology that you could pass along.
At this point, I could interject that I wish there were many more demonstration projects available. So in this I share your disappointment.
But let me compare this to another project I have enjoyed reading about: the updraft solar tower. If you are not familiar it is essentially a greenhouse below tilted to a central chimney. The hot air from the greenhouse is guided through wind turbines to a higher and cooler elevation. There was a reasonably successful pilot project constructed in Spain decades ago. It proved relatively inefficient, but due to thermal storage could produce power 24/7 and had potentially additional revenue streams. A full scale project would be so massive no one wants to build one. An Australian promoter of the technology seems at times to be a bit of a gold digging scammer. I doubt it will go anywhere until the latest patents expire.
Now another interjection. Are you simply copy and pasting the last half of your above comment, because it seems as if you keep saying the exact thing.
So here are two different types of projects that both involve energy storage. Between the two PHES seems to be guided by a wider group, with appropriate background, researchers (vs entrepreneurs) and associated with a university giving me more confidence it its potential. If you are going to paint both of these and all other storage technologies with the same (lacking confidence) wide brush, I would have to say at the very least, you don’t seem to be much of a painter.
Frank you make good points re heat conversion losses and low efficiency. Well taken but misapplied due to changing load market conditions as well as declining generation costs for wind which are NOW The CHEAPEST Form of Generation in the US. Period end of story.
Even if the net efficiency is 30 to 35 % it is a winner to use the excess wind electricity from a wind turbine and store it into Molten salt and then use that heat to run a steam turbine ( most likely some hybrid mated to the other one).
Siemens will figure this out and we can wait for the end results to see if they economics work out.
Then during the day from Noon to * PM during peak hours they make needed electricity and turn off expensive peakers. Save Gas which will only increase in price going forward.
Also the thermal efficiency for most vintage nukes and coal is in the 30 to 35 % level Now. And with coal as they age it goes down . We been living with Mid 30’s efficiency and even into the mid 20’s range as coal plants age for decades.
The lights did not go off!
So the stored wind can allow more aggressive expansion of Abundance of Wind ( free fuel ) – no disposal costs or environmental trade offs like with coal ( coal slurry and ash ponds are toxic) and the 1 to 2 $$$ Billion decommissioning costs for Nukes along with the ongoing radiation waste issue costs are all Avoided.
The Energy Generation Paradigm is changing and we don’t need nor can we afford large under utilized Big Plants.
Having clean energy available at the time it is needed most is the Primary Driver in all the equations. The losses that you point out are tolerable as that is what we live with now. Except we have fuel costs and other costs.
Wind as it now is, reaches 45 % capacity factors on land. Off shore will be slightly higher. However due to the existing base load plants built for a different era meeting declining load at night ; wind sometimes gets crowded off the market. Some times it goes the other way and disrupts coal and nukes operating costs. AKA NY and Illinois – wind hurting high cost nukes.
In Texas and other States they have to Spill the Wind as they say when there is excess generating and load is down. Cost effective storage is a Game Changer !
Wind can store heat at night when load is down and then dispatch much needed energy during the Peak time periods. That is the Driver the difference maker.
Specific Efficiency while important is not as limiting as it once was.
We have free fuel energy w wind and solar and soon wave energy so it makes a big difference in how one would approach design issues going forward.
Frank your efficiency concerns are valid but time of load need is the real driver and using $.025 kwhr cost of new wind to generate heat for storage makes sense when you can take that heat and sell electricity for $ higher daytime wholesale prices $. In Ercot region it runs from $ .09 to .!6 cents or much more .
As the Nation phases out the Production Tax credit for Wind the need to sell during the peak times will drive the issue. They will not have to Spill the Wind as happens now. Time w Tell.
While we want our energy work to “be efficient,” the “inefficiency” of renewable energy is not equal to the inefficiency of fossil fuel plants. For fossil fuel multiple tons of coal or gas are dumped into the plant. Every bit of that tonage gives us pollution. Efficiency tells us how much electricity we get out compared to how much energy was in that fossil fuel. But the pollution is 100% of the chemical product.
When it comes to renewable energy again we have energy entering into the production facility and we get a percentage of useful energy coming out. But we don’t get the pollution aspect from any level of inefficiency.
For renewable energy then we are much more concerned with the capital costs and any pollution associated with construction. In this regard the eventual holy grail may eventually be floating wind turbines which could have a very marginal carbon footprint.
Breath drives home the decision drivers RE Wind has no fuel costs so no pollution waste stream in contrast to fossil fuel.
The lower capital cost that wind features when matched to a steam turbine that creates heat and then runs off that heat when its needed is example of the much talked about future Smart Grid Generation model that the market will evolve towards.
The Grid Integration Efficiency is the real driving factor not the efficiency loss in the system.
Smarter Grid and Cleaner Grid a doable combination
Thank you Breath on Wind for Sharing those two good examples of Hybrid Energy storage R & D very interesting to see where these Boutique hybrid systems end up in the marketplace.
Your post though is not included in the chain of postings. ??
Frank despite the limitations of RE energy systems – though many are working to reduce them RE leads the total new generation ranking Globally with close to 152 GW Deployed in 2015.
The nuclear Genie’s Megawatts are not even close in fact they lag behind Hydro, GAS and even dirty Coal.
Coal though is slipping and will be a minor player within 20 years with the new build pipeline shrinking and drying up. Check out India’s $ 3.2 Billion new Solar Manufacturing program.
Those in the KNOW are making these decisions.
By that time storage technologies and other technologies will have closed the limitation GAPs for RE.
We have High Winds at our Back and are Leading the Way as we Sail Stronger into the Future.
Silent, very often my postings are “held for moderation.” I suspect that this is because of the number of cites.
Breath on wind thanks for clarifying now I get it.
Your Posts are good discourse and reflective and carry weight.
I must begin refraining from Posting due to tome demands. Craig just keeps firing out concepts that interest me.
Hard to speak to these issues with bumper sticker slogans LOL
Thanks & Have good days where ever you may be.