How Energy Storage Systems Could Replace Natural Gas Power Plants

[thackney]

How Energy Storage Systems Could Replace Natural Gas Power Plants
https://www.fool.com/investing/2018/01/25/why-energy-storage-systems-could-replace-natural-g.aspx

Energy storage has gotten so cheap that it's now replacing natural gas peaker plants around the world.

One of the reasons natural gas has grown to become the largest energy source for electricity in the U.S. is that it's a very flexible energy source. It can provide baseload power for the grid, and peaker plants can provide short-duration energy that fills gaps when renewables aren't producing energy or demand is unusually high.

A lot of times the value of the peaker plants is generated in only a few hours per year. In Southern California, peak summer hours require gas power plants to provide supply when the rest of the grid is overloaded, which leads to higher power prices and makes the economics of these power points work. But energy storage systems can provide similar value to the grid at peak hours while providing additional services 365 days per year. As the cost of storage comes down, it could make natural gas peaker plants obsolete, causing another major shift in energy as we know it.

When Tesla built a 20 megawatt/80 megawatt-hour (MWh) energy storage system in Southern California early last year, it was a critical turning point for the industry. Not only was energy storage going to be the supplier power at peak times for the grid, replacing off-line natural gas facilities, but the project was deployed in a matter of months.

Tesla's highly publicized 129 MWh project in South Australia was built in less than 100 days and has already proven it can add value to the grid. A day before it was scheduled to be turned on, the energy storage system was called upon to provide 59 MW of power on an extremely hot day. Over time, it'll help stabilize the grid at times of peak demand, reducing the need for peaker plants.

Tesla isn't the only one in the energy storage game...

[IsailedawayfromFR]

The title is misleading when it says that Energy Storage Systems could replace NG Power Plants.

The article clearly indicates those NG Power Plants that could be replaced are not base load plants, but peaker NG plants only.

And a lot of those NG peaker plants are only required if the base load generating plants are from renewables, which do not run nearly as long as coal, nuclear or NG base load plants and require backup power from another source, which is typically natural gas.

In other words, in those cases, there would be no need for battery storage plants to replace NG peaker plants as there would be no NG peaker plants there in the first place, save for the romance of installing renewables.

 

[thackney]

The title is misleading when it says that Energy Storage Systems could replace NG Power Plants.

The article clearly indicates those NG Power Plants that could be replaced are not base load plants, but peaker NG plants only.

Yep, you gotta read more than the title.  The article is clear it is talking about peaker units.

And a lot of those NG peaker plants are only required if the base load generating plants are from renewables, which do not run nearly as long as coal, nuclear or NG base load plants and require backup power from another source, which is typically natural gas.

Nope, essentially all those peakers were already built for meeting system peak for a few hours.  The ability to run and also back up non-dispatchable sources like wind and solar are just bonus dollars for units already built for another purpose.

In other words, in those cases, there would be no need for battery storage plants to replace NG peaker plants as there would be no NG peaker plants there in the first place, save for the romance of installing renewables.

False.

[InHeavenThereIsNoBeer]

The title is misleading when it says that Energy Storage Systems could replace NG Power Plants.

The article clearly indicates those NG Power Plants that could be replaced are not base load plants, but peaker NG plants only.

And a lot of those NG peaker plants are only required if the base load generating plants are from renewables, which do not run nearly as long as coal, nuclear or NG base load plants and require backup power from another source, which is typically natural gas.

In other words, in those cases, there would be no need for battery storage plants to replace NG peaker plants as there would be no NG peaker plants there in the first place, save for the romance of installing renewables.

Wouldn't these peaker plants also compensate for fluctuations on the demand side?

[thackney]

Wouldn't these peaker plants also compensate for fluctuations on the demand side?

The battery systems are capable of responding much faster, milliseconds versus perhaps a minute or so.

[Bigun]

The battery systems are capable of responding much faster, milliseconds versus perhaps a minute or so.

I'm glad I'm not the schmuck who gets to maintain that battery bank.

[thackney]

I'm glad I'm not the schmuck who gets to maintain that battery bank.

Yeah, I remember a couple decades ago commissioning a UPS system at a power plant we built in the desert.  Lead-acid batteries about 30 inches tall, 12~14 inches square.  180 of them connected up and powered in room half as big as it should have been.  Too small walk spaces...  I would go in there keeping my elbows on my ribs, careful not to lean on anything.  It was not a room to drop a tool in the wrong place.  The amount of stored energy in there gave me the willies, and I like working with voltages and amps measured in the thousands.

When I was in Alaska, the Fairbanks area utility installed a massive battery system that would carry the grid if they had a sudden trip and was short on power before the next generator could be brought online.  That was impressive but could only operate at full load for 15 minutes, and not very often.

Now they are building units that are 100 MegaWatts and 400 MegaWatthours.  Most people cannot comprehend the amount of energy stored in there.

[Bigun]

Yeah, I remember a couple decades ago commissioning a UPS system at a power plant we built in the desert.  Lead-acid batteries about 30 inches tall, 12~14 inches square.  180 of them connected up and powered in room half as big as it should have been.  Too small walk spaces...  I would go in there keeping my elbows on my ribs, careful not to lean on anything.  It was not a room to drop a tool in the wrong place.  The amount of stored energy in there gave me the willies, and I like working with voltages and amps measured in the thousands.

When I was in Alaska, the Fairbanks area utility installed a massive battery system that would carry the grid if they had a sudden trip and was short on power before the next generator could be brought online.  That was impressive but could only operate at full load for 15 minutes, and not very often.

Now they are building units that are 100 MegaWatts and 400 MegaWatthours.  Most people cannot comprehend the amount of energy stored in there.

The inverters must be something to behold.

[thackney]

The inverters must be something to behold.

That technology has matured a while ago.  The High Voltage DC Transmission Line Projects often operated at 500,000 Volts and 5,000 Amps for years.  The substations for these lines and massive inverters and rectifiers.

https://www.siemens.com/press/pool/de/feature/2013/energy/2013-08-x-win/factsheet-hvdc-e.pdf

[IsailedawayfromFR]

Nope, essentially all those peakers were already built for meeting system peak for a few hours.  The ability to run and also back up non-dispatchable sources like wind and solar are just bonus dollars for units already built for another purpose.

Then I need something cleared up.

You seem to be suggesting  that the runtime generating abilities(note, not saying that evil word efficiency) of a wind or solar base load system equates to that of a coal, nuclear or NG Plant.  In other words, they do not need any more more backup or peak power needs than those other plants.

Did I read that wrong?

[thackney]

Then I need something cleared up.

You seem to be suggesting  that the runtime generating abilities(note, not saying that evil word efficiency) of a wind or solar base load system equates to that of a coal, nuclear or NG Plant.  In other words, they do not need any more more backup or peak power needs than those other plants.

Did I read that wrong?

Wind and Solar are not base load generation; they do not run all the time.  Also, unlike peakers, they are not dispatchable, meaning they cannot really be scheduled to be on and off as the market may desire.

They sell power when they make it and they don't sell power when they don't make it.  They are not equal to coal, nuclear or nat gas.

[thackney]

Then I need something cleared up.

Keep in mind, we run large interconnected grids, not small isolated systems.



The Wholesale Market is governed by the System Operator.  Power is bought and sold through the system.  The systems need to be capable of generating plants tripping offline regardless is it is through a mechanical or electrical fault, or a reduction of predicted wind or solar.

Every single day, units come on and off line, usually scheduled, sometimes not.  Spinning reserve and standby reserve need to be in place to keep the grid within tolerance limits.

Pricing varies for different types of generation.  A peaker gets paid a lot more per kWH than a base load unit; but they don't get it for very long.

The System also gets balanced with different levels of interruptable load.  I did work for a Natural Gas Storage unit.  We were on large electric compressors.  But our targets for loading the reservoir were by the month.  We could easily handle being interrupted with no notice for hours at a time.  So we got power at a really cheap rate.  Hospitals pay high rates for dual-redundancy feeds that do not interrupt even in major faults.

Lots of different pieces to balance.  In general the load and generation cycle is predictable, but the system is designed to handle upsets, to a limit. 

[IsailedawayfromFR]

Wind and Solar are not base load generation; they do not run all the time.  Also, unlike peakers, they are not dispatchable, meaning they cannot really be scheduled to be on and off as the market may desire.

They sell power when they make it and they don't sell power when they don't make it.  They are not equal to coal, nuclear or nat gas.

Ok, I see my lack of semantics come into play. 

No base load plants are replaced by wind or solar.  OK.

I need a Power Plant Primer(PPP).  From what I understand, there are

Baseload plants - always coal, nuclear or NG (or Hydro?).  Dispatchable power, but almost always turned on.  Never wind or solar.

Peaker plants - usually NG.  Only needed when base loads are insufficient. Dispatchable power, turned off or on when needed. Never wind or solar.

____ plants - could be hydro, wind, solar or something else?  Non-dispatchable power, which I guess means when they run they are used with priority at the expense of something else which is then turned off or reduced, which could be either a base load or a peaker plant.

[thackney]

@IsailedawayfromFR

First look at a daily demand curve:



So in using round numbers, for this day only, Baseload units are going to be supplying 35 Gigawatts.

But today, another 30 Gigawatts are going to eventually be needed.  The won't run most of the time.  There is a lot of swing of power that needs to come up and back down.  But clearly, most of it isn't going to run most of the time.

Weather forecasts give the system operator decent predictions of what they will see as load and what they will see from wind and solar.  The wind may have gusts and moments of lull, but not all over at once.  The pressure systems provide fairly predicable power on an day and hourly basis.

Hydro is actually dispatchable, just not on 0 to 100% capacity.  Typically you have an allowed stream flow that needs to move so much water per day, but can vary perhaps 25% to 75% on a quick basis, while waiting on other units to come up.  Or it can bump up for the peak and pull back for the bottom.  For example, Niagara Falls actually produces more at night, when the tourist attraction of the falls isn't needed as much.

Combined cycle natural gas can produce some power in minutes, but to reach full capacity and high-efficiency may take hours for full heat of the steam.

http://www.powerengineeringint.com/articles/print/volume-16/issue-2/features/flexible-power/the-need-for-flexible-speed-0-100-mw-in-minutes.html

There are different levels of power payments, contracted base load, daily power bids, immediate spot market pricing, etc.  Producers of power modify their output to maximize their payments versus their costs.  Gas Turbine units can quickly back off and use less fuel if they are supplying to a spot market that dropped in price due to more supply or less demand.

The plant I work can have an upset condition.  With no notice at all, we might drop 80 MW of load (very unusual, but it happens)  Some immediate changes in the system can help balance.  For example, load drops, system voltage rises, demand increases to the voltage rise helping to draw more load.  The frequency can have a impact as well but has to balance over time, easiest to ignore that for our purpose.  But somewhere in the system, that 80 MW needs to come off the supply or get wheeled across the system to another area more economic to drop supply.

Does all this help?

Now realize the day night swing is greatly changed throughout the year.



Weather can make quite a difference, a cold snap in the winter can make a near peak demand at night.

[IsailedawayfromFR]

@thackney

Helps a lot.  Knew rather than stumbling around to go to the source.

I know i have a few more questions.  One is how can wind or solar ever be anything but costly since a baseload needs them only at certain times to supplement power on those peaks?  Do they actually cause baseload plants to be cutback as they have some type of priority over whatever baseload or peak system operating?

In other words, are people forced to take renewables?  If not, how could they possibly compete in the open market as they tend to be on the extremes of expensive?

Got others after I get a good rest.

[thackney]

@thackney

Helps a lot.  Knew rather than stumbling around to go to the source.

I know i have a few more questions.  One is how can wind or solar ever be anything but costly since a baseload needs them only at certain times to supplement power on those peaks?  Do they actually cause baseload plants to be cutback as they have some type of priority over whatever baseload or peak system operating?

In other words, are people forced to take renewables?  If not, how could they possibly compete in the open market as they tend to be on the extremes of expensive?

Got others after I get a good rest.

All the power producers from any source bid to provide power.  System Operators make forecasts of what they need for tomorrow.  Immediate Spot Market varies to handle differences between real demand and forecast.

The following may help with the rules from different System Operators, although a bit dated.

http://www.nerc.com/docs/pc/ivgtf/WindinMarketsTableAug09(2-4Task_Force).pdf

[thackney]

@IsailedawayfromFR

The following article helps explain the scheduling of intermittent power.  Combined with the rules in the article above, let me know if that make sense.

https://blogs.scientificamerican.com/plugged-in/renewable-energy-intermittency-explained-challenges-solutions-and-opportunities/

Combining intermittent with utility sized energy storage is going to help.