Isn’t 4 hours of battery storage much too low? How is that considered “reliable”? What am I missing?
Grid demand is also significantly higher in the daytime so that 4h of battery allows you to very closely match users demands over 24 hours or ramp up during peak demand and fall back on other sources at night.
Furthermore, cost of storage is falling even faster than wind or solar ever did. Wait until next year, and you get lots more storage for your money.
Finally, batteries are good for very short-term storage -- their round-trip efficiency and fast response are unbeatable -- but they cost more than alternatives. For storage that you don't need to draw down every night, something you can fill cheap tanks with is better even if round-trip efficiency is low. Something you can also sell when your local tanks are full, and buy if they seem likely to go dry, is better yet.
So, expect to see a lot of anhydrous ammonia long-term storage. Also, hydrogen, and liquid nitrogen. And, lots of tropical sites synthesizing for export to higher latitudes in winter, and lots of higher-latitude cities importing it, via ship, in place of LNG and oil.
It is kind of surprising to see the batteries set up in Morocco, not in UK. That might be politics. Typically, storage is best sited near point-of-use. Maybe part of the deal is Morocco gets to use a share of the energy.
This is wishful thinking. These are very much research projects at present.
> Also, hydrogen, and liquid nitrogen.
Hydrogen makes no sense as energy storage. The energy costs of compression (and liquefaction, if you do that), and the risks, are just silly. Liquifying and regasifiying nitrogen are energy-expensive too.
It'd be better to combine hydrogen with air-captured carbon to make medium-chain hydrocarbons. We can store those at room temperature and pressure safely for season-long periods of time, as demonstrated by hundreds of millions of motor vehicles and tens of thousands of fuel depots.
Leaks of liquid hydrocarbons are much less likely to kill people than leaks of ammonia.
Hydrogen storage will be mostly underground, at low pressure. So, no compression or liquification needed. But, for transport it will be liquified and shipped just like LNG is today.
Liquifying nitrogen is extremely mature technology. A 100MW LN2 storage plant is under construction in Chile. Little hint, again: [ ... ]
"Re-gasifying" liquid nitrogen needs only ambient air, which (little hint) is all well above the boiling point of nitrogen.
If you think liquifying hydrogen takes a lot of energy, wait until you find out how much you need to synthesize hydrocarbons. Little hint: you will need a lot of hydrogen stockpiled. And, a lot of carbon with all the oxygen picked off.
Plenty of experimental GW scale nuclear reactors have been built, just look at the history of CANDU design for an example. That’s just the scale this stuff operates at, you need real world data to demonstrate it’s actually cost effective at scale and actually building stuff still requires actual R&D. Further, you don’t want to just build one you want multiple examples to see what costs look like when people building the thing have relevant experience.
Nuclear reactors have very difficult engineering problems unknown in most other technologies. For a nuke, you might actually need to build a GW-scale pilot plant to discover the failure modes that show up there. Not so, most things. A bigger dam just needs more turbines. A bigger wind farm just needs more wind turbines. A bigger solar farm just needs more panels. A bigger ammonia plant just needs more catalyzer units. You can start it running after the first one, and add more at leisure.
That is a thing that makes renewables + storage so much more attractive than nukes: You are guaranteed no unpleasant surprises, and no existential disasters. That it is also radically cheaper, and starts working immediately, is icing on a very nice cake.
Scale always brings new problems. The difference between hosting a website from your personal internet connection and building TickTock’s infrastructure isn’t simply writing a bigger check to someone.
How many people know how to build X. Where do you get the raw materials or parts etc, all to often the answer is you build a factory or a mine. Many basic assumptions break down with scale. You don’t use even close to the same equipment to connect your houses solar panels to the grid as you would a 1GW solar farm.
As to location. All the equipment you need for moving solar power around the grid like long distance power lines is exactly the same equipment you need for moving battery power at that location around the grid. Even better batteries charged with solar power get to avoid DC>AC inefficiency selling solar to the grid and AC>DC inefficiency charging the batteries. They get to skip out on equipment like redundant DC>AC inverters etc. You are even moving power through cooler power lines that therefore have less resistance.
And, storage adjacent to the point of use is less at risk of being wholly unavailable, e.g. if there is a problem with the cable. So, you need good reasons to put it somewhere else. That is not to say there cannot be such reasons, but what they are is of interest.
Storage closer to consumers has a huge number of issues being more expensive to manage, harder to scale, less efficient, etc etc. It sounds vastly more useful than it is because you end up increasing failure modes and make failing safe much harder.
In fact, as this particular transmission line will be feeding into the UK national grid, its normal role will be backup for offshore wind.
That somebody else at the end of a different transmission line might want access to the battery would be a good reason to site it where those lines meet. Another might be that you need to minimize fluctuations on power going through your transmission line. But whatever the reasons, they certainly will not be trivial, and might be revelatory. Trivially dismissing the question adds no light.
Require vast investments to add the capacity to handle storage and would be less efficient.
Your proposal is basically to spend 20% to 30% more money, loses and extra 4-7% electricity every charge discharge cycle and gains effectively nothing which is why nobody is doing it.
> how you top up local storage during supply peaks when you haven't got a local surplus.
Peak + filling storage requires extra transmission capacity which costs money to build and energy to use.
> At the end of a different transmission line.
Transmission lines work in either direction and are generally set up as an interconnected mesh. You want redundancy from the solar power plant to customers, but you also want redundancy from batteries to customers.
Ex: “you need to minimize fluctuations on power going through your transmission line.” That sounds reasonable, yes you need to maintain grid frequency etc, but it’s got almost nothing to do with transmission lines. Further there is equipment to deal with various transitory issues that is much cheaper than a giant battery + required equipment to connect those batteries to the electric grid.
So even your pedantic objections are misinformed.
Let’s look at a HVDC list: https://en.wikipedia.org/wiki/List_of_HVDC_projects
VS say: https://cecgis-caenergy.opendata.arcgis.com/datasets/260b451...
Looks like as I said HVDC are rare. It’s ok not to be an expert on something but don’t try to fake it you just look like a fool.
As to the topic, if you want to bring up unrelated and experimental storage technology then don’t pretend to be “shocked” that the topic expands.
:sigh: Well a win is a win.
In other words, the battery would bridge exactly 4 hours of 0% power generation. The moment you have more than 0% power generation but still less than 100%, the battery will last more than 4 hours of wall clock time.
It is usually a mistake to overbuild batteries. The money is better spent on PV panels, wind turbines, and grid tie-ins and, eventually, other storage media.
Also, the "time" of the battery is just a function of storage size and inverter sizing at peak discharge. It's often selected based on how the operator expects it to be used. (For example, Tesla sells megapacks in 2hr/4hr variants [1], and I think a lot of other grid-scale storage works this way. A 2hr megapack replaces some battery bays with more inverters.) While the battery is 4 hour capable, the operator could really intend for this to provide a constant overnight supply, and it could certainly provide that.
Please forgive my naive question. I have exactly zero relevant expertise.
The grid is one of the world's largest real-time reactive machines. Power is generated on the fly as you need it. You could draw a direct path from your home A/C switching on all the way back up the chain to some source needing to push power to meet your demand.
The supply of the grid is a big mix of diverse sources: renewables, natural gas, hydro, nuclear, coal—whatever. Each power source has different pros and cons, and you cannot really over-index on one to have a reliable grid. For example, nuclear is a fantastic and relatively clean source for base load (obviously, when handled responsibly), but not great to provide power that reacts to the shifts of demand through the day. Solar, obviously, doesn't work at night. The grid operator has to build a supply mix that fits the needs of their region. (And that's typically by facilitating energy market with different energy products where generators bid and participate.)
"A week's worth of storage" feels somewhat like an armchair simplification. It roughly sounds on target if we're moving toward the march of nines for real-time zero-carbon power supply, but...that honestly doesn't need to be the target expectation for today. Long term goal, yes. Today's targets really should be to get to 90-95% renewable, since chasing the last 5% will be the hardest and most expensive—and that's probably where we can acceptably use some dirtier backup sources. With the state of the grid today, there's lots and lots of power sources that can be replaced for cheaper and cleaner before we need to chase the long tail of 100% renewable at all hours during every season.
The reality though, is that all of these requirements are modeled, and the operator surely has their install min/maxed for typical use.
At the risk of being off topic, I personally have what energy-wonks could consider a "three hour" system (10kW solar, 15kW/43.5kWh battery, my typical daily energy use is between 25-50kWh, higher if I need to charge the car) and have done two weeks fully off-grid last summer, which included some cloudy weather. (True off-grid: the utility breaker was open to hard disconnect from the grid). While I could probably live full-time off grid in the summer, I definitely feel its better to have my system help clean up the grid where possible. So there's really a lot of flexibility to be had depending on the system's requirements.
It is. The way I've heard it explained by energy experts (or people who were introduced by the media as such) was that storage needs to be on the order of days/weeks, not hours. I'm sure that's something of a crude oversimplification for a lay audience and certainly not a rugged analysis for this particular project.
> With the state of the grid today, there's lots and lots of power sources that can be replaced for cheaper and cleaner before we need to chase the long tail of 100% renewable at all hours during every season.
I'm of the impression that "clean carbon" peaker-plants are fairly inefficient because there's a fair amount of overhead in starting them and consequently they don't actually end up being that much cleaner. :/ Unfortunately, I wish I had more to offer than "this is what I've heard an alleged energy expert say". :(