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If you are interested in this, you really should go watch the Tesla battery day presentation.
A few of their techniques will MASSIVELY reduce the cost per kwh of battery storage. They already have around $100/kwh tech and they are looking at reducing it to ~$50/kwh. Their big issue today is scaling. It's not that the batteries aren't cheap, it's that they simply can't make enough of them (they are scarce).
Tesla is way ahead of the curve when it comes to battery manufacturing, they have to be for their EVs. They are about to amp that up even further.
Grid batteries have slightly different requirements compared to EV batteries. Weight/volume doesn't matter. Charge speed isn't a priority. Discharge speed isn't awfully important either. Round trip efficiency and cycle life are even more important. Temperature ranges aren't as wide.
Overall, I think these differences will lead to separate production facilities and differing designs.
According to Tesla battery day they are going to use the same production line to produce three different batteries, varying the cathode. Iron Phosphate for low-cost or full-discharge use cases, Nickel Manganese for mainstream and Nickel for high performance.
Counterintuitively it seems that "make it up with volume" is winning; rather than all sorts of different battery designs (with associated fixed costs of manufacture), they're just going to turn out a billion 18650 cells.
> Counterintuitively it seems that "make it up with volume" is winning;
The 18650 is a form factor, not the chemistry.
Tesla uses the 18650 in the Model S and X but uses a 21700 form factor for the Model 3, Powerwall and Powerpack. They announced during their Battery Day event the transition to the 4680 form factor.
The Powerwall and Powerpack uses a Lithium NMC chemistry which is different from the Lithium NCA chemistry used in their automobiles.
* Clarification
> Grid batteries have slightly different requirements compared to EV batteries. Weight/volume doesn't matter. Charge speed isn't a priority. [...]
I have the impression that Tesla tweaks the chemistry depending on the application. The cells used for power wall and grid storage might be slightly different to take advantage of those differences.
While weight/volume isn't important itself, reducing the weight/volume per kWh will also tend to reduce the cost per kWh since you're using less materials.
There are storage solutions that go further in taking advantage of the points you mention, such as flow batteries, but in that case I think it can be expensive to get high power output. The article mentions that price per kW is also important. With batteries you automatically get more watts the more watt-hours you add, which is useful in many cases.
They do, the Powerwall and Powerpack use a Lithium NMC chemistry as opposed to Lithium NCA used in their automobiles.
>Discharge speed isn't awfully important either
"On December 14, the Loy Yang coal power plant — one of the largest in Australia — suddenly went offline. In an instant, the grid shed 560 MW of electricity, enough to power 170,000 homes. 600 miles away, the Hornsdale Power Reserve battery system, as the Tesla system is officially known, kicked in within 140 milliseconds. It reacted so quickly, in fact, that the local grid operator was unable to measure the response time accurately. "
https://cleantechnica.com/2017/12/27/tesla-grid-storage-batt...
The article mentioned that the battery was only able to supply 16MW to the grid. By all means a significant amount, but nowhere near the required 560MW needed to stabilize the grid.
This is where hydro-based power plants excel, they're able to adjust the power output as quickly as gravity can push the water down the pipes. They're able to ramp up from almost no output to full capacity in minutes. Gas-turbines are also able to do this.
"Minutes" is not "140 miliseconds".
But it's well worth reading
https://www.ofgem.gov.uk/system/files/docs/2019/09/eso_techn...
on an actual UK grid trip event to see what kind of things can happen; start at "summary of event" on p4. Note the three paragraphs starting with "However" as subsequent stability systems also failed.
> This made the cumulative loss of generation 1,691MW
(!)
> All of the available “backup” power had already been deployed
That UK grid trip event was going to happen one day. The "Vector shift protection" and "Rate of Change of Frequency" in embedded generation (Home solar etc.) means that if it senses anything "funny", it'll shut off.
Which in turn means if anything else goes wrong with the grid and there isn't enough generation, then all home solar countrywide cuts out, making the problem 10x worse.
Lesson learned: "I detected something weird, lets turn off" is not a good algorithm for everyone to use on a system requiring high uptime!
It was obvious from the start really...
That's switching speed, not discharge speed. Discharge speed is how many amps a battery can put out.
The amount of power for charging or discharging is not the same thing as the latency to start sending power.
A Tesla car rapidly accelerating is over a megawatt. This installation is far more cells than 560 cars worth. That means each individual cell can afford to discharge slower.
> Temperature ranges aren't as wide.
I thought people were mounting these out in the garage.
For me that would be an 80° delta between the highest summer highs and the lowest winter low. The delta in places like Wyoming would be a lot more.
Big fixed installations (think multi megawatt industrial sites) have far more batteries compared to surface area. That means it makes sense to simply wrap the batteries in insulation and use heaters to keep them warm over the winter. Sure, you use a little power to do that, but you gain back far more performance.
For $50 worth of electricity, you can keep something the size of a refrigerator 40 degrees F warmer than the outdoor air all year if you can surround it with an insulating box 2 inches thick.
In a car, the volume to surface area ratio is worse, and you can't guarantee it won't be left in the cold for months without a grid connection, so you need to ensure the chemistry can work cold.
I'm more familiar with Alaska and had a 130ËšF delta between the high and low air temp. The garages I'm familiar with were always insulated and contained the furnace. Even if the garage was unheated, the excess heat from the furnace and insulation would keep the inside above freezing. Also, the insulation and lack of windows would keep the garage cool in the summer.
Presumably that’s less range than in a car driving around in Wyoming?
Yes. In fact the thinking is that increasingly grid batteries will be sodium-ion, because weight is not that big of a deal. Additionally, we have enormous quantities of sodium available, which is why it's predicted to be significantly cheaper in a decade.
> Charge speed isn't a priority. Discharge speed isn't awfully important either.
Not yet, but if power production becomes more volatile (more wind/solar and ???) without associated demand response, how quickly you can charge and discharge starts impacting your duty cycle (“inventory turns per hour”).
I don't think that's necessarily the case for sufficiently large installations unless the cells are _really_ slow. For any grid-scale battery you're going to have many thousands of individual cells linked together. Even if each cell is individually only capable of relatively small charge/discharge rates, it shouldn't matter at the scale of the whole installation for normal supply/demand scenarios. I would only expect brown-out situations if something bad happens to the grid (like PG&E decides to shut down power distribution elsewhere because of fire risk...)
I think there's some applications for high discharge cells. The local car ferry is electrifying, and they're planning on charging at every docking. On my side, our grid power is somewhat fragile, and they're adding redundant wiring between substations (it will be a loop instead of a tree), and a battery bank at the substation nearest the ferry dock, to ease the peak demand.
I think there will always be a trade-off where charge/discharge rates need to be comparable to the durations of peaks and troughs in supply/demand or else capacity must be over-provisioned. If peaks/troughs last N hours and you have K times the minimum capacity needed, then each cell needs to charge/discharge in N/K hours.
If you’re a public utility, sure.
But a faster recharge lets you do more of your buying the absolute trough. And faster discharge lets you capture more of any spike (but that’s less valuable methinks).
Kinda like being able to charge your Tesla with a bigger circuit at home so you don’t have to charge as much during peak hours.
More wind and solar tends to decrease volatility on the short term, while increasing the diurnal and seasonal variation.
A big market for grid batteries then becomes "frequency stabilisation services": they are paid not for actual turnover, but for being there and able to respond to demand within an AC cycle.
Are they allowing off-grid people to buy their batteries yet? The last time I tried to talk to them, they refused to discuss anything that was not grid-tied. In the mean time, I've been looking into LifePO4 batteries as they appear to be a little safer.
Unfortunately, it looks like the their home power division is taking a back seat to their car division. I really hope that changes when they get more battery capacity.
That said, the sad truth is they may abandon it in favor of doing utility storage solutions :(. I'd really love to do a solar + power wall setup for my own home.
If you don't go through tesla, you might be able to get a powerwall supplier to install it for an off grid solution. However, I hear powerwalls are in short supply (and for good reason, they are the cheapest storage solution on the market).
> Unfortunately, it looks like the their home power division is taking a back seat to their car division.
This is not accurate. Tesla's stationary storage unit is seeing unprecedented demand outstripping their supply of cells [1], and they are prioritizing deployment in geographies where they have partnerships (South Australia [2] and Vermont's Green Mountain Power territory [3], both of which are deploying distributed storage as large virtual batteries [VPPs]). Off-grid applications simply aren't a priority at this time (and there are other vendors for such applications, such as Enphase, SunPower, and Generac, who are offering stationary storage for off grid), as grid tie batteries offer more value both to electrical consumers and the electrical grid.
[1]
https://www.utilitydive.com/news/tremendous-demand-for-stati...
[2]
https://reneweconomy.com.au/tesla-vpp-expands-to-add-virtual...
[3]
https://pv-magazine-usa.com/2020/05/26/green-mountain-powers...
EDIT @boulos: That wasn't my interpretation, but if that's the case, I hope my citations are still helpful.
@boulos is correct. That was my bad writing :)
I don't know which has a higher priority for tesla, utility or car manufacturing. It looks like both have a higher priority than the home battery distribution (hence the ever increasing price of the powerwall without increasing capacity).
Powerwall remains the best choice in the market for home energy storage, if you can get one.
Isn’t the person you’re responding to saying exactly that? Tesla is prioritizing utility storage over home storage (and your links provide helpful evidence).
I wonder if logistics plays any role in this? Between miles traveled and not being able to use any mains power tools.
Current and last generation cordless power tools can be pretty sweet, and the ads always show professionals using them (don't you want to play dress-up like the real adults?), but I'm never clear how deep that market penetration is.
For the batteries, that's pretty terrestrial, so cords aren't that big of a problem, unless there's no power grid. I could see the solar guys being largely cordless though. I don't want to die because I tripped over your power/pneumatic lines.
(also how much of this would be solved if Tesla started using their own truck for construction?)
Agreed.
I learned about Wright's Law via Munro Live's (or someone adjacent) coverage of battery day. It's akin to Moore's Law for manufacturing, production. Paraphrasing, unit cost goes down predictably as production ramps up.
Per Munro, Tesla's projections for cost reduction nicely follows Wright's Law and is entirely reasonable.
> Their big issue today is scaling.
Brian from Real Engineering did a video on this subject recently (referencing the Tesla's battery day presentation):
https://www.youtube.com/watch?v=1Xwxe0wU4b8
At $50/kwh you could battery back up a _large_ house for ~48 hours for about $5000.
I find it interesting that such rapidly falling cost actually slow down adoption. My parents will have to renew their houses roof next year and obviously, adding solar with a battery would make sense. However, while doing so would technically be cheaper than buying power from the grid, it would be even cheaper to do it in two (or four, or six ...) years to come as batteries will be even cheaper then. So they probably will not buy them now.
If your parents are in the US and their utility net metering arrangement is favorable [1], they should consider buying rooftop solar next year if they have an interest and their finances allow, as the federal tax credit is slowly phasing out (26% of the total cost is a credit this year, next year it declines to 22%, and there is no credit after 2021). They should confirm with their installer that their inverter is storage ready, which enables them to add a battery in the future when costs decline further, while capturing available incentives and cheaper power today. I'm making some assumptions, but I highly encourage getting three quotes from installers through
, a quote from Tesla [2] (usually cheapest but you might have to aggressively project manage them), and compare systems to their historical electrical consumption. Feel free to bring quotes to
for community review and feedback.
[1]
https://www.solarpowerworldonline.com/2020/03/which-states-o...
[2]
https://www.tesla.com/energy/design
They are not, though similar schemes apply here, but I appreciate your effort for writing it down. Nevertheless, four percent of tax credit are not much if technology prices decrease by 30% or more. That does not mean that we totally reject the idea but its not like a decision of type 'the best time to plant a tree was twenty years ago, the second best time is now'.
Why would a credit be going away?
That's how the legislation was written. One might put forth that those writing it and voting for it thought that constraint to be reasonable (to bootstrap renewables until their cost was low enough to stand on their own without subsidies). Alternatively, one might also consider that the phase out was too soon considering the challenges we face from climate change (and that Congress might consider not only re-upping the credit, but also expanding it back to 30% of total system cost).
This happens to be why economists tend to fear deflation far more than inflation.
I fancied myself a future game designer when I was starting out, so I spent a lot of time while playing games trying to figure out how they ticked, what made them work or unravel over time, especially in multiplayer.
Deflation in a game economy is a sure way to ruin things for everyone. Soon every new character is running around with the third-best hat on, and the fourth best sword. With such a compressed distance between typical and exceptional, everyone becomes muted. What's there to hope for? Why do I even bother to try, when good enough takes no effort at all?
There were several points where my decision to play a game came down to my read of the game economy. If they had no coherent solution to the deflation problem, thanks but no thanks.
I don't know how directly these motivators translate to the real world, but people are people and I can see things getting pretty bad.
Mostly economists fear inflation because people have obligations specified in nominal terms, like salaries and mortgage payments, that they might end up not being able to pay if currency increases in value too much.
And probably why most modern economists happen to be clowns, only fit for a circus and properly to be laughed at.
In the post WW2 era the world has seen next to zero sustained deflation in any major economies, including in Japan (the supposed capital example of deflation for the past quarter century).
As always with the world being overwhelmingly ruled by Keynesian economics, inflation is the destroyer of worlds, not deflation. While economists hold up the false bogeyman of deflation, inflation is actively and persistently destroying economic value, from the US to Europe to Asia. If I were a conspiracy theory type, I'd have to believe they were using the deflation scarecrow on purpose to distract from the way their Keynesian model inevitably destroys everything it touches.
All you have to do is ask an economist, fearing their great fake bogeyman of deflation, for several prominent examples of deflation in the Venezuela or Zimbabwe outcome model of inflationary destruction. Watch as they panic and run for cover. Given how much they all supposedly fear deflation, you'd think there are dozens of recent prominent examples of deflation damaging economies as inflation has harmed the US since ~1970, or how inflation has rocked countries like Argentina.
Take Japan as the long held up example of the great modern economist fear re deflation. They all think Japan has been suffering from persistent deflation for roughly 25 years give or take. Why are consumer prices in Japan so high after decades of persistent deflation? Why is real estate still so expensive in all of their major cities? It's because they didn't actually suffer decades of persistent deflation, other than some modest stagnation-caused pricing pressure from weak consumer demand.
What Japan has actually suffered from is the opposite: they spent their brains out on infrastructure to exceptionally mediocre returns, mis-allocating capital they loaded up on debt to an epic degree, the cost and allocation of which robbed their economy of free capital to invest toward growth, leading to a heat death stagnation. Modern economists, being witch doctors as they are, then proceeded to confuse all of that with ... deflation, because the alternative is to admit that their Keynesian model failed spectacularly in Japan (and it's still failing). In reality Japan massively inflated via very large rounds of deficit spending, debased the Yen aggressively and it all failed. To this day, the modern economics profession refuses to acknowledge the failure of their model in Japan, instead proclaiming that somehow Japan failed to spend enough, they needed to inflate even more aggressively (and say goodbye to the Japanese standard of living accordingly, as that approach has wiped out 1/3 of their standard of living in just the past decade).
Next up, modern economists proclaim the US is suffering from deflation, as the US spends its brains out, leading to increasing stagnation of growth (already underway the past decade plus) as more and more free capital is allocated to servicing giant debt costs and is locked up in low yield trash debt, depriving the economy of the capital it needs to grow. Their cure: spend more, inflate more, debase the USD more. The end result: Japan.
> In the post WW2 era the world has seen next to zero sustained deflation in any major economies
That doesn't prove that economists are fools to fear it, it just proves that policy makers, particularly at central banks, have been listening to them and acting to prevent it.
I thought Li-Ion was roughly 1000 charge-discharge cycles? Once per day, that’s three years, so you I buy the batteries now and when you replace them in a few years the new ones will be even better value?
Or am I making a bad assumption by thinking they’ll have one cycle per day?
1000 cycle lifetime would mainly be if you were doing full charges and discharges (10-90% charge/discharge or worse).
This is from mid 2018, but you can see that model s/x batteries were hitting about 90% capacity after 250,000km which is verrryy roughly 700-800 charge cycles.
https://electrek.co/wp-content/uploads/sites/3/2018/04/scree...
Grid storage batteries are going to be charged and discharged at more reasonable rates than cars. Tesla's superchargers run at 50-250kW and discharging is going to be above 1MW at times, which is not kind to batteries.
I think you can expect quality grid storage setups to last 2000-3000 cycles at this time depending on their environment.
Keep in mind that these cycle lifetimes are to 80% life, so if you're willing to go down to 50% capacity you can expect longer lifetimes, probably closing in on 15-20 years of use.
I am glad to be wrong; this makes batteries an even better idea than I already thought!
The 1000 number is the bad assumption. Grid attached storage is usually designed to cycle once per day for more than a decade.
I'd say house batteries are about ÂŁ500/$750 per kw in UK now. Plus tax and installation... So cheaper than they were but still waiting for big price drops to feed through really.
LCOE of batteries is 10x the LCOE of generation from my understanding.
Taking the mid points of the ranges from Lazard's latest:
https://www.lazard.com/perspective/lcoe2020
Solar is about $35/MWh, and storage, including the energy to charge the battery, is about $190/MWh. So the multiple is now about 5x.
This ratio is key for determining the balance between overprovisioning generation capacity versus storage. When excess generation capacity is cheaper, we will lean harder into that and use less storage, and when storage is cheap we will use more of that and have less excess power.
Given the prices listed in the article, that sounds like it was true for the dates listed, but both (PV) generation and (Tesla) batteries are cheaper now than they were in 2018, and I calculate Tesla batteries cost less than 7.5x even for the best generation.
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https://www.carbonbrief.org/solar-is-now-cheapest-electricit...
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https://www.theverge.com/2020/9/22/21450916/tesla-battery-pa...
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