A Massive Battery that Can Store Solar and Wind Energy
bloomberg.com
bloomberg.com
Since 1/10 Austria and Germany are not in the same energy zone anymore, the pricing zone was split up. This was done because too much renewable power feeding in at near zero cost in Germany was flooding the markets and pushing too much strain on the grid. Heavily needed power lines weren't built because people were protesting.
So the first week has passed were the zones are actually split up and we can see that energy prices are way higher in Austria than in Germany, see [1]. Sure, a more definite answer would need to look at a longer time span. The highest difference actually was on 3/10, where baseload in Germany was 18.29 €/MWh compared to 60.40€/MWh. And peakload on 3/10 was 17.13 €/MWh in Germany compared to 65.83 €/Mwh in Austria. Solar generation on 3/10 in Germany was 12.5 GW!
So far good for Germany, since they anyway subsidize solar and wind heavily and now have the low prices more or less for them self (not totally because cross border capacities, [4])
I haven't looked so far in the costs of the auxiliary energy, really curious how they develop. Germany has in total probably around 385 MW in battery storage already [3] and lots of battery storage projected for 2019.
[1] https://www.epexspot.com/en/market-data/dayaheadauction [2] https://www.eex-transparency.com/homepage/power/germany/prod... [3] https://www.powerengineeringint.com/articles/2018/03/battery... [4] https://www.entsoe.eu/data/map/
My idea on this was to use the batteries of the new electric cars to store energy and take it for the peaks. This would need cooperation with the carparks of the big companies to provide free battery loading during the day vs sucking off peak voltages in the morning and at noon. In the late afternoon the battery must be full, what happens in the morning and at noon is for the grid. This solves the electric car problem, and the grid problem with not enough north-south lines.
One of the biggest difficulties is going to be dealing with the economics of battery degradation. You can limit the pull on any given battery to somewhat lessen the impact, but doing so also limits V2G's impact on the grid. Presumably, utilities would pay for battery usage. If so, how does that affect the economics: I can't say either way, but I'd expect the marginal cost of 'renting' EV batteries to be greater than just buying your own for dedicated storage.
0. http://iopscience.iop.org/article/10.1088/1748-9326/aabe97/m...
http://electricmountain.co.uk/Dinorwig-Power-Station
It has three main roles on the national grid:
1. Near instant response for peak demand fluctuations (e.g. half time during major sports events). 2. Bootstrapping generator for rebooting the national grid should we ever need to. 3. Grid frequency regulation (keeping that AC at 50Hz)
There are a number of projects in progress to look at consumer side Demand Side Regulation (DSR) to provide the latter two grid services without having to carve out mountains or build massive battery farm like Tesla.
Electric mountain is primarily designed to handle the shortist term electrical demands ie putting kettles on (massive demand spike) during tv breaks for the most popular TV programmes. Fortunately the video recorder and subsequent personal recording technology and internet streaming on-demand helps to lesson the demand on Electric Mountain which is why we may never see another one built in the UK. However our demand for technology is driving up the need for more Nuclear and to a lessor extent coal fired power stations, but the ARM cpu is helping to play its part in reducing energy requirements as will parallel processing to mitigate the need for super fast AMD64 cpu's.
Base line demands are met (in order of scaling up or down to meet demand) is nuclear, then coal, gas, hydro including electric mountain. Electric mountain pumps the water back up when surplus electricity is available during the night.
During the week in Feb 2018 when the Beast from the East hit the UK, the realtime gas price on the energy market went off the scale. As more evidence and awareness stacks up that we are going into what is dubbed the Eddy Minimum (a grand solar minimum last seen some 500years ago), so people will take more steps to have a certain level of redundancy built into their homes (where possible LPG/OIL tanks on their property) in order to help mitigate extreme weather events.
Currently if everyone were to live a US lifestyle we would need 4 planet Earths, a UK lifestyle 2.5 planet Earths and so on.
Demand may be getting more stable, but supply is going in the other direction! There is a need for energy storage as the UK grid moves to more renewable and intermittent energy sources, predominantly wind.
Pumped hydro stations like Dinorwig can help lessen the need for fossil-fueled thermal power plants to provide spinning reserve / frequency maintenance. So can batteries.
Whether we will see any more pumped hydro built in the UK probably comes down to cost and environmental concerns, when considered relative to other storage technologies like batteries and electric vehicles with V2G.
Maybe staggering the schedules of TV programs to even this out would be a great idea. After all, now that most people get their tv signal via digital cable rather than over the air, this should be a lot easier to implement. Even +-5 minutes might smooth out those spikes quite a bit.
spoiler: not remotely possible to scale large enough for total world needs.
"If we drained one meter from every upper lake, we would get 54 billion kWh of energy: about a sixth of the target capacity. If performed over seven days, the flow would be 375,000 cubic meters per second, or 125 times the normal flow over the falls."
"We would need 10,000 Raccoon Mountains to meet my baseline energy capacity"
This article was about storing off-peak green energy for peak usage. We're talking only about an hour or two of usage? Not 7 days. Those number may pencil out very well.
Yeah, not with those assumptions.
Storing enough energy for 7-days worth of zero-sun and zero-wind is going to be basically impossible across all known energy storage technologies. We'll likely have to run peaker plants during such an extended outage.
But we're not even trying to solve the 7-days worth of energy problem. We're starting with: lets save 3-hours worth of energy, so that the 6pm sun can be used for air-conditioning until 9pm or so.
Which we're not at yet (see the "Duck Curve" or "Nessie curve").
Besides, being able to store energy for 1 or 2 hours is still SUPER useful. Wind is strongest at night, while Solar is strongest during noon. Having energy at dawn (sun isn't strong yet) or twilight (sun is setting, but the wind hasn't picked up yet) is going to be a huge portion of our future energy strategy.
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A huge part of the problem can be solved behaviorally and economically. We can change the price of electricity based on how easy it is to produce. 12:00 noon (highest sun power) can be cheaper, and 3am power (max wind energy) can also be cheaper.
Night-time energy can be used to power electric cars. 12:00 noon power can be used for factory work and other high-energy tasks (Air Conditioning, Washing Machines).
We all can change our behavior to reduce our energy demand between 5pm and 8pm, to reduce the Nessie curve / duck curve. And we can use economics to set the price higher to encourage others to follow our lead.
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Throw down a bit of nuclear, and keep a few natural gas peaker plants active for emergencies, and I think we've got a strong future for energy.
At the end of the day: Pumped Hydro is the ONLY GW-hr solution to this energy storage question. CAES is hundreds-of-MW-hrs, while Lithium Ion is also only hundreds-of MW-hrs.
That's just how the cookie crumbles: we don't have any other technology to store GW-hrs of energy.
Storage is still a poor solution to this problem it’s much cheaper to have excess renuables.
Would there be much improvement if you could tweak the orientation to match the seasons? E.g. tilt them down toward the horizon during the winter?
It's certainly a huge complication to have motorized panels that move all the time to track the sun. But maybe it wouldn't be that much of a hassle to go out there and manually reorient them (just in 1 axis) a few times a year?
I mean, its not my argument. But... something like the Dust Bowl of the 1930s or even a large volcanic eruption (like the 1980s Mount St. Helen eruption) would block out the sun in a local area for multiple days.
But my point being: such disasters are beyond our storage capabilities by several magnitudes. Most energy storage projects are at best, aiming for a few hours of energy storage.
Many (ie: Flywheels, typical Batteries, etc. etc.) are aiming for minutes, or even just seconds of grid-energy storage. This idea of days-long or even a week-long energy storage is just devoid from reality.
Of course, which is why variable minute-by-minute pricing of electricity can serve as a "battery". The air conditioner, for example, can cool the house to the lowest comfortable temperature while power is cheap, which will then act as a zero-cost "battery" when the electricity gets more expensive in the evening.
I'd certainly do that.
In fact, if I was designing a house under such a regime, I'd design it to incorporate lots of thermal mass within the envelope of the house to make it more effective.
What I noticed when looking at this stuff is 'green building' codes are really about green washing natural gas and expensive toxic high R value insulation. Last thing I saw before I stopped researching was an article where and industry shill was crowing that they'd closed the loophole that allowed builders and home owners to use solar energy to offset insulation requirements.
The loophole was centered around, instead of spending $50,000 to install thick foam insulation with it's attendant issues with mold. Install $20k worth of solar panels, a heat pump and thermal mass inside the house.
which doesn't support mold. I've been very pleased with it. My house is shaded by large trees, so solar would never pencil out.
I'm just kinda sad that my idea of concrete "batteries" with variable pricing never gets any traction. People just can't seem to get past the notion that consumer electricity rates must be constant 24/7 despite enormous expense to make that happen.
Time of Use pricing exists in Portland. But it hasn't been done right. Even the utility itself admits: Time of Use is best if you use most of your electricity late at night or on weekends. If not, you will not benefit from this plan.
So, unless you want to charge an EV at night, or have "concrete batteries", variable pricing here is dumb.
When I discussed the perverse pricing with someone here whose job is literally to promote EVs, that person agreed, saying more or less: "Yeah, I looked into this for myself. I might be able to save $5/month and I might have to pay an extra $35/month."
Current fixed price electricity here is 7.2 ¢ per kWh. (plus other charges such as distribution cost).
Switch to time of use and pay 14.6 ¢ per kWh between 6 AM and 3 PM, and again between 8 PM and 10 PM.
At the peak between 3 PM and 8 PM pay 20 ¢ per kWh.
The cheap rate is 4.2 ¢ per kWh, between 10 PM and 6 AM weekdays, and all day on Sunday.
Hmmm ... let me see. I can pay 7.2 ¢ all the time ... or I can pay 14.6 ¢ or 20.0 ¢ most of the time ... and get cheap prices when my demand is lowest.
Fixed price is a no-brainer decision for most people. They don't give a fuck about the "enormous expense to make that happen"; most people will choose the plan that costs them less per month.
https://www.portlandgeneral.com/residential/power-choices/ti...
Thank you for pointing that out so I don't have to. He's tossing an insane requirement in there and hoping you don't notice. So instead of needing storage to shift about 20-30% of power needs on a daily basis he claims an absolute requirement of 700% of daily usage. Making any solution 20-30 times more costly.
Consider the alternative, as we have snow days. We could have 'energy days' where non-essential demand gets cut off and we fire up some combined cycle plants.
Also I'm not wading through his website again but last time I looked he was studiously ignoring thermal storage. Running that calculation is pretty easy. But he doesn't. Because it's doable even with his deranged 7 day requirement.
The Bloomergites certainly have the chops to unravel and explain this corner of utility economics. Wish they'd do it! The smart-grid future holds all kinds of energy flows into and out of storage. Storage can be characterized in a bunch of ways.
* Total energy capacity (mWh)
* Peak discharge rate (mW)
* Rampup time for discharge. Rampup is most of the content of this article. The 100mW Tesla-built Hornsdale Power Reserve in South Australia has a subsecond rampup time, which makes its energy very valuable for short periods of time.
* Local efficiency (mWh discharged / mWh ingested)
* System efficiency (mWh at source / mWh at sink, counting transmission loss. The lines up to a mountain dam and back down have losses).
* Money efficiency. Taxes, fees, etc.
* Peak ingestion rate (mW)
* Rampup time for ingestion
* Capital cost (please include externalities like decommissioning and disposal costs)
* Expected lifetime (pump storage lifetime is very long)
* Operating cost
The future smart grid needs a finely tuned balance of capacity, rate, and rampup time to succeed.
Electrical grid operators are already really experienced with the process of building substations, basically get a square or rectangular plot of land, level it, put down concrete pads for transformers and switch gear, cover the rest of it in gravel, erect fence with barbed wire around the perimeter. Now do the same but add more concrete pads for big, 20'/40' container sized batteries.
Don't forget NIMBY.
About 56 years ago the utility for New York City wanted to build a pumped storage plant about 30 miles north. It was vigorously opposed and eventually defeated.
Why should people who live in pretty rural areas sacrifice their quality of life to help those who live in a crime infested, filty concrete jungle? That's a bit hyperbolic, but that's what NIMBY boils down to.
https://en.wikipedia.org/wiki/Storm_King_Mountain_(New_York)...
[1] https://en.wikipedia.org/wiki/Nant_de_Drance_Hydropower_Plan...
https://en.wikipedia.org/wiki/Carters_Dam
On a side note, the imagery in the article is very good
I was trying to figure out how to design a system that, given 4 hours of full sunlight at the maximum output of the solar charger (300w) or 4 * 300 w = 1200w total daily charging of my deep cycles. If the system is 100% efficient (it isn't), this gives me 50w a hour over a 24 hour period. 1200w / 24 hr = 50w. But my solar panels exceed the ability of the charge controller. How can I use that to my advantage? I have a well and a holding tank. I was trying to figure out a circuit, perhaps an Arduino program/circuit, with voltage/amp sensors and relays to do this: If there is enough sun, charge the battery. If the batteries are full, turn on the well pump into the holding tank (there's a pressure switch to turn it off when the tank is full). And put the holding tank up on the hill -- which should give me 25-30psi (up 45-50ft). Then I was trying to figure out how to optimize my well pump, or use a DC motor. I might look into salvaging a 2hp DC motor from a treadmill and retrofit it onto a pump housing. Anyway I am trying to optimize for extreme budget. 50w an hour isn't a lot, but it is enough to run a few light bulbs and my tiny refrigerator. I might be able to run a RPi and charge some 18650 batteries for flashlights.
I ran into similar problems when I was trying to make my own solar AC this summer. I found the best solution for a budget build is to use used panels. Instead of being able to afford 1 I could get 3. Now I have enough power to charge my battery fully and run the AC.
Thanks
There are times when this is not practical, but when it is it helps to defray operating costs.
Its hard to build up a casual sense for how much water is lost to evaporation in most lakes we have experience with because the lake's level is based on geography (level of the outlet) when there's a source of water coming in to replenish it. It could be a larger factor than we think.
That said, I expect that the efficiency losses in the pumping and generation steps would dwarf evaporation. Any storage system has some losses; the ability to store larger volumes makes up for efficiency disadvantages compared to things like batteries might have.
The water flowing into the top reservoir of these systems from higher up in the mountains should be able to make up for free for the water lost to evaporation. (If there is not sufficient flow to allow that, then you are going to have a hard time keeping a full reservoir there in the first place).
Evaporation should only be a problem when a system does not have free water from a higher source. I'd expect the most common reason for that would be in cold climates where for part of the year the water that would run down and replenish evaporation is stuck as snow or ice up the mountain.
When you pump some water back to the higher reservoir from the lower reservoir it will raise the water level in the higher reservoir, but probably won't raise the evaporation rate significantly, for the evaporation rate is a function of the surface area, and if the walls are steep at the water level the surface area won't change much.
The only evaporation that should be counted against the water you pumped up is the extra evaporation due to that minor change in surface area.
https://qz.com/1355672/stacking-concrete-blocks-is-a-surpris...
The question is whether we can build enough wind or solar power that doesn't just meet our needs when it's outputting well, but overshoots them by like 500% so we can use cheap and inefficient energy storage.
Such a "battery" could very easily keep the house warm or cool at night depending on the season.
What's required to make this work is to vary the cost of electricity to the consumer, which will incentivize such solutions.
A pile of rocks can also work.
It’s interesting as it is a network of a few dams and rivers over a very large area.
Pumped Hydro is actually pretty awful. Compressed air might work for home needs but will never service industrial needs. Let's hope that a better chemical battery based on sodium and carbon is a reality soon (https://phys.org/news/2018-09-high-capacity-sodium-ion-lithi...).
I don't understand that at all. If you're generating more than you're consuming, then you lose 100% of everything you can't store. Which means 0% efficiency past some point!
But "the round-trip energy efficiency of PSH varies between 70%–80%, with some sources claiming up to 87%."[1]
That's not as good as batteries, which are probably better than 90%, but it doesn't seem bad at all when compared to 0%.
IMO your other arguments are much stronger. Bad to destroy unique geography. Not viable in many places, whether it's because of no water or because of bad geography.
[1] https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...
Whereas even bad batteries have 99% efficiency even counting discharge loss. The problems with those are that they rely on relatively rare metals associated with conflict regions, hence my hopes that we reach a sodium-based battery that will have similar properties to lithium.
Ahhh ... you raise an interesting point which I don't recall reading elsewhere in this discussion (but there may have been new comments posted since my previous pass thru the discussion).
A newly built natural gas plant has an efficiency of perhaps 60%[1]. Recently completed nuclear plants, such as AP1000 based in China, have an efficiency of about 34%.[2]
That's 60% or 34% at the source! There are additional losses from that point forward, whether the energy goes to run pumped hydro or is simply stored in batteries until needed.
[1] https://en.wikipedia.org/wiki/Combined_cycle#Efficiency_of_C... [2] https://en.wikipedia.org/wiki/Sanmen_Nuclear_Power_Station
If the wind's blowing while everyone is asleep it would be wasted anyway if you don't find some way to store it.
Besides, you get free power if your upper reservoir naturally gets a lot of inflow or precipitation :)
Storing electric energy by just raising some mass seems like a pretty good concept - I wonder why It's not adopted further.
https://www.sciencemag.org/news/2016/09/hundreds-new-dams-co...
While dams have failed in the past if built right they can last for centuries.
Also unlike batteries where the majority of the cost sunk is in the batteries themselves with physical storage like this the majority of the cost will be in the construction itself which means that as better pumps and turbines become available you can upgrade your system at a marginal cost.
You compare a hypothetical dam disaster, with nuclears record so far - its clearly worth reconsidering that comparison. Nuclear plants also consume large amounts of water, and other resources so could not be considered carbon neutral by your own measure.
Reservoirs are large lakes, creating them entails ecological disruption but not consumption or degradation in the long term.
And compared to the energy one nuclear plant produces, dams seem to have vastly worse death-per-benefit statistics.
Damming a river can cause ecosystem collapse downstream. That's degradation, as I understand the word. And its definitely long-term.
Potential scenarios are very important in determining probabilistic risk. Simply showing "it hasn't happened yet" is not a valid way to assess risk. This is the reason it costs more to build and keep nuclear plants safe, than it does dams.
No, I’m not.
What actual dam did you mean to refer to there?
"""Its failure in 1975 caused more casualties than any other dam failure in history at an estimated 171,000 deaths and 11 million displaced."""
Though I could also be talking about the 2,209 who died in the 1889 South Fork Dam incident. (“””Blamed locally on poor maintenance by owners; court deemed it an "Act of God". Followed exceptionally heavy rainfall.”””)
Or the 423 in Malpasset dam, France, as recently as 1959.
Or the 238 in Canyon Lake Dam, 1972.
Or the 1,800 to 25,000 (estimates vary) in the 1979 Machchhu dam failure.
It is natural to consider the nature of things - apply equal consideration to nuclear power and your comparison will be more valid.
You wrote "IF it suffers failure..." so the "it" was not the example of failure you gave, "it" was hypothetical . This is why I asked you what "it" was - not so that you could elaborate on what you could have been talking about, I asked to give you a fair chance to realise "it" was yours to define - a hypothetical dam, one defined only by "the nature of things" and a "death toll makes nuclear accidents look like almost nothing"
Wind/Solar can supplement (or even replace it) depending on costs and geographies, but their generation can be very spiky, and you don't get to pick the spikes (or troughs).
Stored-hydro rounds off the trifecta by providing spikes on-demand, but also by absorbing over-production from other sources.
Nuclear looks wonderful in a "spherical cow" calculation, but the reality is that nuclear strongly prefers a constant production, but demand is never constant. Under-production is obviously undesirable, but over-production is no easier to deal with.
So it's not really about which is better - it's balancing the weak points in each system against the strengths of the others.