Maximizing Battery Storage Profits via High-Frequency Intraday Trading
238 comments
·June 12, 2025amluto
ZeroGravitas
Not sure if it's discussed in the paper but apparently in Australia there have already been recorded instances of batteries charging with negative price electricity and then selling back that electricity at a still negative but closer to zero price and so profiting.
When I first heard it, it seemed wild that they couldn't hold on for the price to go back above zero, but I guess if we're talking high frequency trading it makes more sense. They might have bought and sold many times while the price is different levels of negative before switching to charging up in preparation for the later price rises.
And the round trip inefficiency helps too.
petertodd
That's not as ridiculous as it sounds!
As you know, negative electricity prices mean that someone is willing to pay you to dispose of electricity they need to generate for some reason. For example, a conventional steam-turbine-based electricity plant might prefer to just keep running for a brief period of time when demand is low, rather than subject their equipment to a power cycle, which increases their maintenance costs. There's other, dumber, examples based on stupid contracts and badly designed solar... but this example is a reasonable one that exists for good engineering reasons.
The battery provider in this circumstance is profiting from their ability to accept power when demand to dispose of electricity is particularly high. When that need goes down, they can reasonably profit by dumping that energy on someone else who is also able to dispose of the electricity. But at a lower cost. E.g. imagine an big industrial refrigerated storage facility that can consume some excess energy by supercooling their refrigerators. But they can't consume unlimited excess energy, because at some point their warehouse just gets too cold, and they don't have unlimited refrigeration capacity anyway.
So in this simplified example, the battery storage service is getting paid a lot of money to quickly absorb a lot of energy, which they then dump more slowly to the refrigerated warehouse (and similar providers) as the surplus diminishes, in anticipation of another surplus in the near future.
eru
> That's not as ridiculous as it sounds!
I'm not sure: why doesn't someone 'just' put up a few resistive heaters and fans to benefit from negative prices?
kurthr
If it was so profitable, why wouldn't the electricity utility do it themselves? Certainly, they have the scale, infrastructure, and pricing power to do it.
Oh, that's right. This is supposed to be wealth transfer.
foobarian
> and then selling back that electricity at a still negative but closer to zero price and so profiting.
How is it not better to discharge the batteries instead? I guess if you don't have that hardware option integrated into the platform maybe, but otherwise...
adiabatichottub
I don't know why it rankles me to think that generated power should be fed into a dump load just to make the storage owners extra money. Even though it's inefficient at the system level, it shouldn't be harmful releasing energy that would have been eventually dissipated as heat anyways. And yet it still just feel wasteful to me.
I had to go search my bookshelf for this one:
"There has been an increasing awareness among engineers of the last two decades that machines can perform a useful purpose in many applications, even though their characteristics do not conform to the orthodox standards of goodness. The main objective of the engineer is to make money -- to exploit economically the physical properties of materials. Economic considerations, however, do not stop at the first cost of an article, nor at the running cost, but extend to everything connected with that article in the situation in which it is to be used."
nhecker
My shallow understanding is that utilities and grid operators need to manage the supply/load ratio carefully to keep the grid's operating frequency in a very narrow band, centered around 50 or 60 Hertz. If supply outstrips demand, and assuming supply can't react [quickly enough], the operating frequency starts to rise as all the rotating masses connected to the grid gain momentum from the additional power. If the operating frequency increases too much outside of design parameters that could end badly.
So one solution is to incite demand (with negative rates) for folks to ramp up their use of electricity (into e.g., a dump load resistor bank), bringing demand back in line with supply, and bringing the operating frequency back under control.
I hate the waste, agreed. But it would be irresponsible of the operator to bank that extra supply energy into the momentum of spinning things owned by the consumers just so they could pull it out later by intentionally under-supplying. E.g., an aquarium's big water pumps designed to spin only so fast or produce so much pressure might not like being operated at 110% the rated speed at random times of the day.
related links:
https://fnetpublic.utk.edu/frequencygauge.html (you can watch the grid frequency fluctuate in real-time, here!)
MostlyStable
The grid connected thermostats, where the energy provider has (some amount of) control over when you heat/cool your house are pretty unpopular (I know people who have had their AC turned off during heat waves and were not very pleased). But this seems like an application of that that people would like? And most people would probably even be happy with just dramatically reduced/free heating/cooling and not actually needing to get paid. And of course it has the added benefit of actually using the energy in a useful manner, rather than just wasting it.
colechristensen
>I don't know why it rankles me to think that generated power should be fed into a dump load just to make the storage owners extra money. Even though it's inefficient at the system level, it shouldn't be harmful releasing energy that would have been eventually dissipated as heat anyways. And yet it still just feel wasteful to me.
This is one of those efficient market things where you need to manage the market in order that wasteful things happen sometimes... but that waste is an opportunity.
If you and your competitor are both in the business of dumping energy into heat, you're going to compete with each other for access to that money.
Then one of you is going to try to find a way to make _more_ money with that energy and find something quickly scalable with not-too-high idle overhead costs to do with that energy besides just flowing through a resistor.
Negative prices are a sign of an inefficient market or just the lag time between a changing landscape of resources and someone to utilize them.
If there's a free resource someone's going to figure out how to use it, just let it hang out for a while and the problem fixes itself.
Especially with solar energy, this is just going to be a thing. There's a certain balance where overprovisioning is cheaper than storage and so you just do that. Then you wait for industry (or consumers) to figure out how to take advantage of the intermittent cheap energy.
eru
> Then one of you is going to try to find a way to make _more_ money with that energy and find something quickly scalable with not-too-high idle overhead costs to do with that energy besides just flowing through a resistor.
Yes, exactly.
Which reminds me of the occasional story about how one native group or another was so in tune with nature, because they used every part of the (insert important animal here).
Modern economies obviously use all parts of the animal, for exactly the reason you outline.
> Especially with solar energy, this is just going to be a thing. There's a certain balance where overprovisioning is cheaper than storage and so you just do that. Then you wait for industry (or consumers) to figure out how to take advantage of the intermittent cheap energy.
Yes, though you also need to make sure that regulations don't get in the way. Or at least not too badly.
One example I can think of is forcing utilities to charge people by net-metering, forcing the utility to implicitly pay the same price for electricity as they charge. We don't do that for eg used car salesmen.
hwillis
> Surely the power electronics or even just the control algorithms in a BESS could be slightly modified to consume power, get warm, and not transfer any current to or from the battery cells, effectively taking advantage of the BESS’s heat sink to sink excess power and sell that service.
Unless you specifically design for it (specifically, with a dummy load), the efficiency of the system is inversely proportional to its ability to do this. You need a secondary system.
The power system can connect the battery terminal to in or to out, so if you switch both on at once you effectively bypass the battery. It's called shoot-through current and is generally considered a destructive process. If you can switch on and off fast enough you could limit it to a non-destructive level, but in practice most systems will not switch fast enough. They are designed to operate with the battery load, which is at minimum ~10x higher resistance than the transistor itself. In practice it is often 100s of times higher.
That's where the efficiency comes into it. If a power system is 98% efficient (pretty normal- this does not include power lost to heat in the battery itself), that means the electronics can only burn 1/50th as much power as normally passes through the system. Worse, when you put the switch into shorted position it will try to pass 50x its rated current. You need to switch much faster -certainly more than 50x faster- and that will probably put it outside its operating region.
It is relatively easy to just have a large resistor, but it is not very well suited to use battery power systems. Batteries are very low impedance, and the power system exists to transform to a lower voltage and higher current. Resistors are cheaper when they are higher voltage, so the power system is a hacky kludge.
The overall solution is just more batteries. Oversupply is a transient problem and always will be.
ACCount36
> Unless you specifically design for it (specifically, with a dummy load), the efficiency of the system is inversely proportional to its ability to do this. You need a secondary system.
Many multicell BMS already have this kind of "power shedding" capability. They use it for cell balancing - to equalize voltage between cells with slightly different characteristics. This is desirable despite the power waste, because it reduces wear, increases charging efficiency and allows battery packs to last longer.
Some battery packs are also designed to be able to dump enough power into heat to be able to keep the batteries warm during extreme cold.
ranma42
The amount of power you can dump for balancing is just a fraction of the charge/discharge power (because it only needs to offset differences in self-discharge rate). So you still need a proper dummy load when you want to dump more.
Similarly, the heatsinking capacity of the battery is designed for charging/discharging losses (say 5% of charge/discharge power).
jordz
I work in the industry making hardware and software for large scale commercial and grid scale storage.
There are several challenges with this, safety, thermal runaway, and life cycle of the asset which has a limited amount of cycles.
Also the architecture of the system for the AC inverters and the DC side can come from very different places in the supply chain and aren’t as vertically integrated leaving you in a position where you can’t actually make this work without compromising something in the supply chain. That being said we are talking about a LOT of energy in these systems and to dissipate that much heat you’d need a load bank.
andoma
Our house have geothermal heating (heatpump conncted to 160m drilled hole, pretty common in Scandinavia). The heatpump supports having a coolant loop for cooling the house in the summer. Thus the heat pump pretty much exchanges heat from the house to the well (heating it up ever so slightly). It would certainly be possible to insert a resistive dummy load on that loop and just store that heat in the bedrock as well.
frabert
This! Or, if you don't have geothermal heating but have an electric water heater, maybe temporarily increase the temperature it goes to: maybe it's normally set to go to 65C, then when you detect that you have negative prices and your batteries are full and your water already hot, maybe heat the water to 70C and store that little bit of extra energy as heat! If you have thermostatic valves in your bathrooms, you won't even notice the difference except by the fact that your water heater now can apparently hold a little bit more water than usual :)
holri
I have a heat pump for hot water and calculated this with an offered floating energy tariff. It is not economical because the high net tariffs are not floating but fixed per kwH and negative / very low prices are seldom here and only for a short period of time available.
cogman10
Assuming regular negatives (more than once a day) you could also tie the heating to the grid prices with maybe an hour buffer around your high water usage times to make sure you are up to temp.
Modern water heaters will keep temp for a shockingly long period of time.
_trampeltier
I know a country, the national train company turns lots of outside lights on (daytime), if the price is negative.
cyri
Yes that is the SBB in Switzerland but they do not turn the lights, instead they turn on the heaters for the track switches. Not sure if that is all rumours.
_Algernon_
Great for the local insect population.
matthewdgreen
Wouldn't that discharge the battery and hence contribute to battery wear, by wasting a charge cycle?
triceratops
If you have free energy the obvious thing to use it for is carbon capture.
rtkwe
The big problem there is you have these intensely capital expensive capture plants sitting idle around 75% of the time. Also the processes may not gracefully start and stop though maybe you could smooth that out by building a huge battery bank along with the CC plant to effectively run a full duty cycle with 'free' energy. That bumps the capital costs up again though so the economics get tricky.
rcxdude
Yeah. Anything that's designed to use nearly-free or negative-priced energy from the grid needs to be cheap to build and easy to start and stop (The former being one of the main issues with the 'bitcoin mining as grid management' idea).
ZeroGravitas
The real low hanging fruit is energy use you were going to do earlier/later anyway but where timing isn't important.
Heating water, cooling water, pumping water, charging batteries, running power hungry machines.
It's half century old tech and usually the only thing missing is a financial incentive to do so.
bee_rider
I wonder if desalination would be another good use. But, yeah, it is probably just a matter of how fast the processes can absorb extra power.
positr0n
The problem is desalination plants cost billions. You're not going to make money building one then running it the 1% of the time the price of electricity is negative.
cogman10
District heating and cooling would be an excellent sink for the power.
Water needs a lot of energy to cool or heat, concentrated at a district, you could easily absorb a lot of energy at negative prices.
ic_fly2
I have programmed batteries / algos to do this in some European markets. This is being done right now.
The yield you could make from batteries in the UK dropped from double digits to 2% in 8months once some hedge funds figured out how to build and bid (or commission companies like my employer) batteries in the UK short term reserve market.
There are a few firms in northern Jutland and London specialised in this sort of trading.
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baq
At least the grid is better off and it’s not all approximately zero sum…
friendzis
That's a very bold statement.
Huge part of the reason why negative prices exist in the first place is separation of generation and transmission. With pay-as-clear model negligible-variable-costs generators (i.e. renewables) can bid at zero and pump more into the grid than the local segment can drain, requiring artificial balancing sinks. However, the cost of artificial sinks fall on the grid as transmission costs and are not reflected in the wholesale market.
dschaurecker
Are/where you already trading at a second to sub-second level on the continuous intraday markets? How did you backtest your strategies then, if so? Or is backtesting, e.g. for parametric extensions of the optimization, not yet quite relevant?
azernik
Sometimes the efficient market happens to you (and that's good)
Horffupolde
That’s yield over what base?
jillesvangurp
Battery production rates are creeping up to multiple twh/year now. This is accumulating to a lot of battery sitting around in vehicles, domestic storage, grid storage, etc. Mostly the goal of these batteries of course isn't supporting the grid but some other use case. But if it's plugged in, it could potentially be available for selling power. Right now, most EVs can't contribute power. But that's something that is starting to change. Small experiments with thousands or tens of thousands of vehicles have already been done and seem to work fine. Now imagine tens of millions of vehicles being part of the grid. That's a serious amount of stand by power for absorbing excess power or dispatching power when needed.
Another interesting aspect is that as grid demand fluctuates, a lot of cables are under utilized at least some of the time. Which means there is plenty of capacity for charging batteries provided there is excess generation and cable capacity. A lot of that power currently gets discarded instead. Batteries allow better use of this excess power. And having a lot of local battery means that cable capacity can be freed up as well when needed and then recharged when demand reduces.
And then finally battery prices are coming down. With sodium ion cell production ramping up in several places, things could get quite a bit cheaper. These don't depend on scarce metals or materials. And they last quite long as well (relative to NMC).
giantg2
"Right now, most EVs can't contribute power"
Nor should they. People don't want to be cycling their batteries and reducing their life. This use case would be better served by batteries that are designed for that purpose instead of being designed to be light for a vehicle.
schiffern
EV can grid cooperate without adding charge/discharge cycles. You just intelligently schedule the charging.
This is how most Time-of-Use metering already works. The driver sets a minimum battery percentage to charge immediately (eg 40% range, enough to reach the local hospital), and then schedule a time when the car should be fully charged (eg 80% by 7AM). The software just Does The Right Thing, using the same prediction and bidding algorithms as stationary batteries.
The search term is "V1G" (a cheeky reference to unidirectional V2G).
SirFredman
Indeed. I live in The Netherlands and use the Jedlix app to schedule charging, which works in this way. The grid operator can use this to selectively create or shed load in a specific area, which helps to stabilize the grid. Really nifty.
inetknght
> People don't want to be cycling their batteries and reducing their life.
More battery cycles just costs money. For the right price, I'd do it.
But more than that: I don't want to be stranded without power in my vehicle because someone in the electric grid made poor power management decisions and decided to offload that decision to consumers.
eldaisfish
as with anything, it's not just money. Losing battery capacity in an EV is a hassle. A hassle because you charge more frequently, a hassle because you will eventually need a battery change, and so on. What is the price of all that hassle?
That said, most EV incentive programs use around 10% (often less) of an EV battery capacity so the actual effects are barely noticeable.
usefulcat
In general I agree with that, but I think it really would depend on the price. For at least some people it would surely be worthwhile for the right price.
giantg2
If the price is high enough, EVs still lose out since you can make more profit creating battery farms with cheaper batteries that are cheaper to replace. You can't make it expensive enough to cover the replacement of a Tesla battery without making it attractive enough for someone else to use ea more efficient model.
wjnc
Future: Cycle the power when profitable, replace the batteries when depleted enough? Batteries in cars are many times the domestic demand of a given home, at least in temperate climates.
tomas789
They are almost the same batteries. Different form factor but same thing. They are rolled from the same lines.
giantg2
Grid level batteries use many different forms. You even have stuff like pumped hydro and controlled drop concrete. Even if the battery cells are exactly the same, the replacement cost is much higher in a vehicle due to the configuration.
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HankB99
> A lot of that power currently gets discarded instead.
How is power discarded? I would expect peaking generation to be cut back or perhaps even base load plants can reduce output. (AFAIK "base load" means they are expected to be kept operating continuously whereas "peaking" is designed to start up when needed and shut down when not.)
jillesvangurp
wind mills are weather vaned (i.e. not broken, but deliberately turned off), solar panels excess energy is curtailed (prevented from going into the grid) and usually transformed into heat on the panels or in inverters.
As for baseload. It's one of those waffly terms that's rarely specified in GW that is needed. Which as it turns out is far less than we used to have given that much of it was replaced with wind and solar over the last decade or so. The real question is how low can we go with this stuff before we need some more solutions. Some would say all the way but the consensus is that the last 5-10% might get very hard and costly.
Either way, having some peaker plants on stand by ready to spin up over the course of hours/days while batteries slowly deplete is probably a good short term compromise. Replacing spinning mass (fly wheels) with batteries seems a particularly popular and very cost effective use for batteries.
qeternity
> How is power discarded
It isn’t, not at scale in any traditional sense.
mschuster91
> That's a serious amount of stand by power for absorbing excess power or dispatching power when needed.
... and a serious issue should one of the few large manufacturers or remote-control dispatcher/trader companies get hacked. The outage in Spain a few weeks ago was just a small warning, probably caused by a technical malfunction. But now imagine this being used as a side track in an act of war? The first day of the Russian invasion of Ukraine was accompanied by the hack of Viasat satellites, which led to 5.800 wind turbines shutting down due to a lack of remote control capabilities [1]. Now imagine the large Chinese inverter and power bank controller vendors that often enough just white-label for other brands? That's a whole lot of a different game now.
toast0
> and a serious issue should one of the few large manufacturers or remote-control dispatcher/trader companies get hacked. The outage in Spain a few weeks ago was just a small warning, probably caused by a technical malfunction.
If everyone agrees, you can use grid frequency/phase to coordinate, and not a separate realtime communication system. Grid interactive demand/response is a proven way to manage supply and load.
When your section of the grid is stressed, supply power or abstain from charging; when your section of the grid is abundant, charge.
Coordination is useful too, of course; predictive charging is helpful, and you wouldn't get that only by monitoring the grid; you also want to know somehow that a supply or load is scheduled to be added or removed at time X, or was unexpectedly removed and will not be reconnected for some time. And the system operator would want to know about capacity in many dimensions.
mschuster91
It doesn't work that way. Maybe in the US where everyone seems to do their own shit, particularly in Texas, but here in Europe our grid literally spans the entire continent, from Portugal through into Ukraine's front lines, and from Norway even down towards Africa. It's a three phase grid that is in synchronized phase everywhere. Like, literally everywhere.
Grid frequency cannot be used at scale to coordinate energy production as a result, because the grid elements themselves don't know why the frequency is going down on its own or where the cause is. For that you need to monitor the country or region crossing to see where energy is flowing and aggregate this.
Drop a couple gigawatts from the production side, for example, all at once and the frequency will immediately drop, only not crashing due to the mechanical inertia of the large power plants. Immediately, electricity and physics will lead to current balances redistributing and automated systems will kick in (e.g. gas peaker plants ramp up in a matter of seconds, battery storage kicks in even faster). But when too much capacity gets dropped, the available spare capacity isn't enough and eventually the first lines will trip due to overcurrent or frequency deviation. That is what happened in Spain, made worse by the fact that inverters don't have mechanical inertia and so immediately more inverters dropped out for safety reasons as the frequency sagged too much for their protection circuits. The inverse, adding a couple of gigawatts of consumers, causes the same effect.
That's also why very large consumers such as smelters must contact the local electricity distributor in advance before any load change - dispatch must know precisely when the consumer will drop or add load, so that other plants can be regulated up or down to avoid too much of a sag or hike in frequency.
jillesvangurp
Of course the Ukrainians are now much less dependent on central power generations out of necessity. It turns out that all those big power plants and electricity distribution centers make for nice drone targets. The Russians did far more damage with that than with their satellite hackery. Those 5800 wind turbines came back online and are mostly still operational.
The lesson here is that distributed power is a good thing in war time scenarios but you might want to pay attention to digital security. Central power generation becomes a tempting target.
Now the good news with Chinese stuff is that a war is not imminent and we have the benefit of hindsight and can do something about that.
mschuster91
> Now the good news with Chinese stuff is that a war is not imminent and we have the benefit of hindsight and can do something about that.
We are and we have been at war with China (and Russia and North Korea, fwiw) for many years at this point. The ongoing cyberwarfare from either country is more than enough to warrant this label, the problem is we were and are governed by chickens who refuse to accept the reality we are living in and still think that kowtowing to China's every demand will save our economies.
dachworker
I'm not at all familiar with this whole field, but why would you publish a trading strategy if it has potential? Why not sell it to a hedgefund, at least? Or is this research formally publishing what industry is already doing?
throw-qqqqq
Seemingly profitable strategies are actually published all the time in finance literature.
Some also work (usually only for a short amount of time if profitable), most don’t really work at all for various technical reasons (lookahead bias, model doesn’t account for slip/trading costs or assume infinite liquidity or a portfolio too large to realistically rebalance etc.) and some again work, but have unfavorable risk-adjusted return profiles compared to simpler strategies.
yxhuvud
Or in the case of batteries: Requires a whole lot of hardware to be bought to get a reasonable economy of scale.
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dschaurecker
Most real-world optimizations for flexible storage assets currently work across multiple markets, sometimes also with more sophisticated boundary conditions. What we show is that high-frequency trading on the continuous intraday market is relevant, especially when training for more optimal parametrized strategies.
It also seems like a sensible idea to publish details and theories about an idea, not necessarily a finished trading product though ;)
chardz
On top of what others have mentioned, this paper also sidesteps forecasting electricity prices, which is already a very complicated problem (particularly in U.S markets where we have zonal pricing) needed to build profitable battery systems that actually operate on the grid.
I've had a few chats with some folks working on battery startups, and I think the more conventional approach is to forecast prices + run an optimization to find optimal storage decisions. You could measure the system's performance by looking at how well the algorithm does when it has perfect information about prices (obviously, when you have perfect information about prices it is trivial to optimize the battery).
dschaurecker
Our two follow-up papers are addressing exactly this (for Europe)! We are extending our high-frequency continuous intraday approach (CID) with a forecast-based day-ahead bidding stage, and subsequent CID forecast updates.
I'd also be quite interested in strategies for grid-scale BESS trading in the US' real-time markets. Do you know more about it, or could forward me to someone who would be willing to talk about it? ;)
chardz
I'm afraid I'm not too familiar with BESS in particular, and the people I spoke to are probably not too keen on sharing much (which is generally true of those who work in U.S markets). Unfortunately it's all very opaque.
I'd be happy to provide you the names of the firms I spoke to over email, if that would be of use!
loehnsberg
There‘s still a lot of work left to do to go from an academic prototype to live trading: real-time data, market access, SCADA, compliance & legal, security, … Also you must be a physical player that owns the battery and/or right to use it and not just do paper trading.
7thaccount
There is "virtual" (paper) trading in the day ahead markets in the US, but it's just for amounts of energy. You can't make a fake battery for the grid operator to optimize.
Gys
Is the trading strategy making substantial returns (at least a few percent) on the full investment (batteries, electronics, subscriptions)? Otherwise this is only relevant for battery owners that benefit already by other means (using the battery at night for home owners, for example).
h4kor
This isn't a trade "just on paper". You need real hardware integrated into the grid.
Energiekomin
The authors are from universities. Publicly funded.
And its not like they can just do that and get rich. Its particular for/with battery storage systems.
Basically making battery storage systems more interesting for investors to invest into.
thelastgallon
Just use EVs. EVs are primarily energy storage devices, some people get to drive them about 20 - 30 mins/day. The remaining 23 hours, it is a energy storage device. It can absorb excess power when price is negative, and can even supply power back to the grid when prices are high!
rafaelmn
Sounds like deprecating a >10k battery pack on a >30k vehicle and reducing your max range with power cycles to earn pennies.
thelastgallon
Its more than pennies[1]. By several orders of magnitude. Car batteries now last longer the rest of the car lifespan, it will be millions of miles soon.
Tesla Electric customers report making as much as $150 a day https://electrek.co/2023/07/05/tesla-electric-customers-repo...
rafaelmn
Lol at 5$ per kWh.
In my country for home consumers the difference between day/night rates is 10-20c/kWh. With spot pricing I can see it working to cover the post commute power spike - but you're effectively doubling your commute discharge rate and pushing charge levels to suboptimal levels.
Batteries might work but at 80% capacity they are worth significantly less than new - both in terms of utility and resale value.
Maybe if battery range gets extended so far that even at 80% capacity it's an overkill - like 1000mile batteries - I could see myself doing something like this - but at current ranges and charging setups - I'll skip the few dozen euro a month.
two_handfuls
Yes, exactly this has been proposed with "smart car chargers," along with other things you can do if the grid operator has some control over a bunch of grid-connected equipment. It hasn't taken off as far as I know, probably because that means the car battery wears out more.
The "virtual power plants" are the closest thing to this idea that is actually done in practice. That's individuals who own batteries joining some collective that then sells to the grid the ability to reduce demand a bit. Tesla did a pilot program with its Powerwalls iirc.
bee_rider
This seems like building more batteries (just, with extra hardware).
An EV could be good for this sort of thing, but I guess it would have to sit around at less than 100% charge, to have the capacity.
bufferoverflow
We almost never charge our EV to 100%, to not degrade the battery faster.
bee_rider
But, if you are going to offer “absorbing energy from the grid as a service” the capacity you have to offer can only be
<absolute max that you are willing to charge your battery to> - <minimum that you are willing have your battery sitting at>
b0a04gl
> “Our method is able to solve over 24 million optimization problems in less than 90 minutes.”
that line is doing heavy lifting. sounds insane until you look closer they batch out embarrassingly parallel, lowdimensional problems no live latencies, no network I/O, no grid API jitter. just hammering a static dataset in memory. real markets stall, disconnect, price slippage, queue delays. none of that here. so yeah, 24 million looks cool in the abstract, but under the hood it's just cleanroom compute; feels like they optimised the benchmark more than the actual system
loehnsberg
Assuming you add all the annoying details that algo trade execution brings, the algorithm still provides the answer on which position to take within a few microseconds, which is what you want if you trade in a limit order book.
b0a04gl
true, you want microsecond decisions at the core, no doubt ; but that’s only half the game. an ideal action in clean memory isn’t the same once it hits fragmented liquidity, stale quotes, partial fills. if the algo doesn’t account for execution drift or book pressure post-placement, the microsecond edge fades fast. so yeah, fast compute’s necessary but not sufficient without modelling the messy tail end too
saltspork
In Australia 5 minute spot pricing is now accessible to many residential customers via retailers like Amber electric. With volatile pricing and a large home battery subsidy from the re-elected government, batteries can quickly pay for themselves through arbitrage alone.
EMHASS is an interesting tool to perform the optimisation.
philjohn
Yep, been using EMHASS for the last couple of years in the UK.
I have a large array (12.8kWp east/west split) but a low export limit of 5kW. In the winter it's charging overnight at 7p per kWh (Intelligent Octopus Go) and then using that stored energy during the day to avoid importing at peak rates, and in the summer it makes sure to discharge most of the battery before the peak generation hours so that battery charges from power which would otherwise be curtailed (discharge to minimise import on my SolarEdge system, but charge from clipped power would also work).
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jakewins
Similarly in Europe; spot market with a big single pay-as-cleared spot auction for every quarter-hour, and then a continuous auction for the same periods closer to delivery, similar to the normal stock market. Millions of residential devices are traded there right now
dschaurecker
Thank you all for the interest in our paper, it is cool to see that people are interested in the topic!
brilee
For those of you suggesting we use the extra energy for $pet_topic I suggest reading https://www.moderndescartes.com/essays/factobattery/
Tldr: most applications of free energy have capital costs that far outweigh the free energy harvest potential.
buu700
This sounds similar to something I suggested at one point: https://news.ycombinator.com/item?id=38669706
Imagine software that could run on EVs, Powerwall-type batteries, computers/tablets/smartphones, and so on, which would automatically charge and discharge for passive income. Essentially algorithmic trading, but with power instead of stock. You'd just have to configure any necessary time ranges and charge percentages, e.g. maybe your EV needs to be at 25% by 8am and again by 5pm on weekdays in order to make your daily commute.
Maybe some EVs will start to come with built-in crypto miners to burn negatively priced power when the battery is at capacity. Maybe Lyft/Uber and Waymo/Cruise will take advantage of it by increasing and lowering rates based on the price of power (if they don't already).
7thaccount
Sorry to be the bearer of bad news, but this isn't novel and something that's been talked about for a long time. The industry term I've most heard is "prices to devices". You of course need retail to participate more in the wholesale markets, but there are a lot of barriers - some technological, some regulatory. Some companies did this in ERCOT, but there was a big backlash when customers got $20k bills after Winter Storm Uri as they didn't understand what they were signing up for.
The FERC passed Order 2222 which is a bigger step in that direction by forcing the regional wholesale markets to allow aggregators to aggregate up the smaller stuff that is normally considered noise.
Dylan16807
> Some companies did this in ERCOT, but there was a big backlash when customers got $20k bills after Winter Storm Uri as they didn't understand what they were signing up for.
It would be a bit weird but you could have your home supply at a fixed-ish rate and your EV on a separate meter riding the raw market.
If you can prevent too much cheating.
infecto
And while not making money, there has been a lot of talk around Virtual Power Plants, that is unifying the larger demand devices to help stabilize the grid in times of peak demand.
7thaccount
Virtual Power Plants (VPPs) are essentially the same thing as the Distributed Energy Resource Aggregators (DERAs) I mentioned above. I guess a VPP is technically a more general term and could also refer to the same concept under different structures like in a micro grid.
The industry has a ton of jargon (literally thousands of acronyms amongst the US regional markets) and in many cases there are 8 terms that mean the exact same thing.
buu700
Interesting, thanks. That doesn't sound like bad news at all.
7thaccount
No I guess not. It can sometimes be a little sad though when you think you've come up with some grand new idea and it's been done.
rtuin
This type of service is becoming increasingly prevalent among European energy suppliers for their residential customers. Beyond providing a revenue stream for consumers this model aggregates distributed energy resources (home batteries, EV's, PV systems) into a one virtual power plant. This enables the storage of surplus energy generated during solar peaks and dispatch back to the grid during periods of high demand. I find it a fascinating domain to work in!
datadrivenangel
I wrote a book on this in 2020 and was already somewhat late to the party, as people were running actual pilot programs a decade earlier!
Also large industrial consumers have been participating in similar approaches for decades. See the crazy clever trading schemes that Enron used to do fraud and drive up prices.
bfayers
I run predbat (https://springfall2008.github.io/batpred/) to achieve something like this with my Home Assistant install to manage my home battery. It can also manage EV charging but I haven't needed to do that yet due to how my tariff works. (Very cheap fixed period overnight).
Energiekomin
Thats what bi-directional charging is for and its already becoming political to force the industry to support this.
And we already have energy provider which provide a tarif for exactly this.
The only idea i hate is the mentioning of crypto. Not only is it waste, it converts the energy in heat which needs to get disipated and potentially wastes even more energy to get this heat away from the current location (ac).
Aeroi
pretty sure nodal energy market trading, duck curve arbitrage is the whole profit play for the tesla power wall/autobidder and the Base Power startup coming out of ERCOT. There is definitely a land rush from energy firms and GIS guys to front run land purchasing near solar buildouts and to build as much grid scale battery storage as possible. The percent swings can be huge. Also a huge rush for this in the Northeast now that the offshore wind contracts have been cancelled.
ccheney
I find Autobidder fascinating, they've been at this for awhile. When I saw this HN post I thought the paper may have come from Tesla themselves.
https://www.tesla.com/support/energy/tesla-software/autobidd...
mellow_observer
A world where individuals are incentivized to use some wasted space to place low maintenance automated trading batteries to make a little money on the side seems like it'd be an interesting solution to the renewable energy storage problem. Put a few units in otherwise useless locations like on roofs or in between highways and make some cash, sounds like a decent investment.
Would there be any expected problems in doing such distributed power storage on a very large scale around the grid that you'd have to account for? Perhaps issues with synchronization, power flow or the possibility of large scale drops in avaialble stored power at times?
soared
Outside of the grid level, maintenance, security, and safety of batteries is important. Many Americans have a garage to securely store their $30k+ car, bike/etc - similar security may be necessary (literally or for the feels) for expensive batteries.
null
fifilura
Or preferably your EV? Requires no extra space or extra investment...
> However, because it is physically not possible to charge and discharge the battery at the same time, such trades have to be prevented.
The authors are observing that, if electricity prices are negative and your battery is not perfectly efficient, then you would like to charge and discharge simultaneously to get paid for wasting energy, but you can’t.
This is a silly limitation. Surely the power electronics or even just the control algorithms in a BESS could be slightly modified to consume power, get warm, and not transfer any current to or from the battery cells, effectively taking advantage of the BESS’s heat sink to sink excess power and sell that service.
More seriously, in a world with occasional negative prices, you would want your battery to be able discharge itself, without exporting power, in a controlled and power-limited manner so as to avoid overheating. And the optimization algorithms should factor this in. I wonder if real grid-scale BESS systems have this capability.