Is that it's their rural landowners that benefit the most from wind and solar farms. It's not East Coast Liberals that own all that land in West Texas - it's their voters.

Can't imagine how difficult it would be to try to raise cattle in West Texas. But some company wants to pay you monthly for either windmills or solar panels on your land?

The article only tells us how much power the batteries can deliver and leave out how long they can deliver it for.

I wrote about the limitations, compared to a generation source.
https://www.democraticunderground.com/1127170924

Anyway, from my education and work background, I am quite well aware of the difference between power and energy. I am always on the lookout for how much energy a battery project is capable of storing, not just its power rating. Both are important.

the energy stored. The usefulness of a battery is directly proportional to the energy stored.

that energy at a one watt trickle, it would be utterly worthless.

of chemicals to store the same amount of energy. The battery is made up of cells and if a certain number of cells of particular chemistry and size is needed to obtain a power level than twice that number would be required to hold twice the energy but only the same size inverter would be required to provide the power.
Again, the energy stored in batteries s proportional to the cost and also to their usefulness.Batteries do not store power, they store energy.

THE POWER CAPACITY IS JUST AS IMPORTANT..

From what I've seen looking at Lithium-ion utility scale batteries, the only ones I've seen in articles that give both the power and energy capacities is that they are all (that I've seen) designed to deliver 4 hours at their maximum capacity, or more hours at reduced capacity. Perhaps that's just an industry design standard, but that's all I've seen. One can just as accurately say their cost is proportional to their power rating.

When a power plant trips offline, the amount of MW that can be quickly ramped up is the more important factor to stabilizing the system. Usually we're talking seconds or minutes. That the batteries can deliver 4 hours of this is moot for system disturbances like these. Whereas for long wind/solar droughts, then both are important.

When a power plant trips offline, it can't be put back on in minutes or probably hours. All the motors and heating systems draw several times running power on startup. The heating elements because resistance goes down when temperature goes down and motors because they draw more current (in the armature) at slower speeds.

be put online in 10-15 minutes. And of course battery storage can, and is ramped up as well, until the supply / load is brought into balance.

EDITED TO ADD FOR CLARITY - the subject line and the above line is in response to this quote: "When a power plant trips offline, it can't be put back on in minutes or probably hours.". I agree that is the case for most generating plants, especially the large ones. But other resources can pick up in seconds or minutes.. /END EDIT

Battery packs serve many functions, including helping to regulate the control area's generation/load balance on a second-by-second basis (Automatic Generation Control, AGC).

"battery back up is not for minute long outages". That's simply not true. Battery storage is useful and used for many purposes, including that.

Another common role is for the battery packs that I've seen are ones attached to a solar project. System load in late afternoon and early evening can be as high or nearly as high as the day's peak, but solar output is diminishing and vanishing. The 4 hours at max capacity (or a few more hours with ramping up and down) is a good fit. Here both the power capacity and energy storage capability are about equally useful to preventing having to start up other generation to cover the few hours solar deficit during system high load periods.

That failure lasted 3 days and had nothing to do with lack of a battery back up. I hope Texas is making a real effort to solve the generation problems that caused that failure rather than spending lots of money on battery backups. Note that the power from batteries decreases when they are cold.

It would be astronomically infeasibly expensive to build batteries to back up a system that simply does not have enough generation that either can be ramped up or put online, and has no ties to other grids that can provide the power, e.g. the Texas system.

As I mentioned in #6 I wrote about the limitations, compared to a generation source, and in particular about the Texas situation:

https://www.democraticunderground.com/1127170924
I wouldn't say the batteries are just useful for a "local" outage. They can help the grid as a whole recover from a plant tripping offline until there's time to get other generation going. (Hopefully there will be other generation offline that can be started and put online -- or already online whose output can be ramped up -- that's usually the case, but might not be the case in Texas during peak conditions).

and this remark about batteries compared to generating plants:

And 4 hours (if these are 4 hour batteries) is not a lot of storage (whereas Prairie Island generates its capacity 24/7/365 with more than 90% capacity factor).

NNadir has written about how, to cover something like the German Dunkleflaute of November - December 2022,

"The 266.4 M Poweralls required for the 30 days in Germany would be 31.6 times the world production of cobalt in 2021." (the 30 days is 11/15 - 12/14/22) https://www.democraticunderground.com/1127158224

I'm not a battery fanatic. That said, they can help with some system issues that I've covered in this thread, and if one has a battery pack on the system, it can and should be utilized.

I'd guess that the utilities that added a battery pack to extend the ability of a solar system to cover high system loads near and after sundown (#12 above) did an economic and performance analysis of that vs. other solutions (like building more gas turbine units). It's possible that the analysts and decision makers were a bunch of ring-a-ding-dongs that made their decision based on ideological biases, but I think that's unlikely.

As for batteries losing a lot of their capability in the cold, I live in Minnesota so I'm well aware of that.

would require a years worth of cobalt. So Powerall batteries do specify the energy stored, at least the ones not sold to Texas.

They also specify the kVA (apparent power, kilo volt amperes) and the real power rating (kW).

An energy storage system is not very useful unless it can deliver its stored energy at a rate that meets at least the important household requirements. (As well as having enough stored energy to keep going as long as needed).

https://digitalassets.tesla.com/tesla-contents/image/upload/powerwall-2-ac-datasheet-en-na_001

because it is not. You need more chemical to store more energy. That means you need more battery to store more energy. The concept isn't difficult.

Last edited Wed Dec 13, 2023, 10:20 PM - Edit history (2)

ITS ENERGY STORAGE CAPABILITY ARE BOTH IMPORTANT. I'm an electrical engineer just like you. I have operational planning experience where a large part of the job is making sure there are enough capacity to meet the load on an hour by hour basis in the most economic manner while meeting reliability requirements. And a masters degree in power systems. I was also involved with area regulation control where load must be met on a second-by-second basis (Automatic Generation Control) or corrective action taken automatically (usually).

EDITED TO ADD (855p CT): I finally looked at the video more closely

At 2:58 they show a table titled "Wind power generation 2022" and the first line on the table is "Texas 114,787 megawatts",
2nd line: "Iowa 45,761 megawatts"

That of course is wrong. Those should be megawatt hours (MWh), not megawatts. Is that what you are talking about? If so, I am appalled and at the same time not surprised at all to see stuff like this in media reports, since I see confusion between MW and MWh all the time.

As I'm sure you know, most journalists fall well short of the upper rungs of technical literacy.

2nd EDIT TO ADD - FWIW, the video didn't mention batteries or any other storage technology or functionality.

NREL: The Four Phases of Storage Deployment: A Framework for the Expanding Role of Storage in the U.S. Power System

I'm pretty sure the fossil fuel companies have done the math and know that wind and solar power are entirely dependent on fossil fuels for their economic viability and will only prolong our use of fossil fuels.

If that was not the case solar and wind power would probably be illegal in Texas.