This special interest group is for professionals to connect and discuss all types of carbon-free power alternatives, including nuclear, renewable, tidal and more.

WARNING: SIGN-IN

You need to be a member of Energy Central to access some features and content. Please or register to continue.

Post

Texas wind and solar power resources shine this summer

image credit: Adobe Stock

The heat came early this summer in Texas.  On Monday, July 13, 2020, during hour 17, the ERCOT (Electric Reliability Council of Texas) market peaked at 74.3 Gigawatts (GW), only 0.2 GW below the all-time ERCOT peak set last summer (2019) on August 12, but a full 3.3 GW above the all-time July peak also set last summer.  During July 2020, ERCOT issued only two Operating Condition Notices (OCNs), one for extreme hot weather with forecast temperatures above 103 degrees Fahrenheit (F), and one warning that tropical storm Hanna might make landfall.  During the month, there were only seven advisories for Physical Responsive Capability (PRCs) < 3,000 MW – an indicator of falling reserve margin.  In comparison, during August 2019, ERCOT issued six OCNs, nine advisory PRCs, one watch for supply dipping below 2,500 MW, and two energy emergency alert level 1’s (EEA1) for reserves dipping below 2,300 MW.  During the EEA1 events, market prices for electricity reached the market cap of $9,000/MWh on several occasions.

ERCOT is one of the largest organized markets in America -the market covers approximately 90% of the largest energy-producing state in the country.  There are more than 26 million customers across the region and more than 46,500 miles of high-voltage transmission.  

Electric Reliability Council of Texas (ERCOT) map

 

Wind and solar were big summer 2020 suppliers

Wind and solar were more significant contributors to load during this summer’s peak compared to last summer.  During July 13 (2020), wind and solar provided 25.4% of the electricity through the day and 18.7% during the peak hour between 4:00 PM and 5:00 PM CT.  In contrast, consider that during last summer’s peak on August 12 (2019), wind and solar provided 17.7% through the day and only 12.9% during the peak hour.

ERCOT Electricity generation, load (MWh) and average real-time LMP ($/MWh)

Summer Peak, July 13, 2020

 

Summer Peak, August 12, 2019

 

There was considerably more thermal power needed to meet the 2019 peak, and it came at a relatively high price.  During the 2019 peak hour, the average real-time (RT) locational marginal prices (LMPs) was $4,159/MWh, while prices during this summer’s peak hour averaged only $25.20/MWh.  The big difference could be attributed to several factors, including adequate surplus capacity at the time of the peak, fewer transmission constraints, and fewer unscheduled plant outages.  Additionally, the availability of more wind and solar power contributed to the low LMPs as the high temperatures across Texas came with windier and sunnier conditions.  Looking closer at this summer’s peak hour compared to last summer’s peak hour, it is apparent that wind and solar resources were more extensive and more consistent power contributors.  

Power prices remain low despite high loads

An analysis prepared by Hitachi ABB Power Grids’ Velocity Suite research team reveals 45 hours where the system load topped 72 GW so far this summer.  In contrast, there were only 31 hours topping 72 GW during the summer of 2019.  On only one occasion did the average RT LMP price top $1,000/MWh in 2020, while there were eight occasions during the summer of 2019 when average LMP prices in ERCOT topped $1,000/MWh.  The average LMP price during the 72+ GW hours this summer was only $145/MWh, while the average for all 72+ GW hours in 2019 was nearly eight times higher at $1,145/MWh.

ERCOT occurrences of hours with > 72-GW loads (MWh) and avg. RT LMP ($/MWh), comparing 2019 (in blue) with 2020 (in orange) 

 

Wind and solar on the rise in Texas

To put in perspective how rapidly both wind and solar power have grown in Texas, consider that wind and solar have increased from virtually zero capacity two decades ago to roughly 34 GW today.  Most of this growth (88.7%) has been from wind farm installations.  In 2020, about 1.4 GW of new wind and 1.1 GW of new solar has already been energized through August.

Texas wind and solar operating capacity by year, MW

 

Wind provided 82.7 million MWh of energy production from Texas power plants in 2019 – up 9.7% from 2018, and up more than 84.4% since 2015.  Solar is beginning to contribute as well, having grown from near zero production in 2015 to 4.3 million MWh in 2019.  During 2019, wind and solar represented 18% of the state’s power production – as recently as 2015, the two renewable resources accounted for just 10% of the state’s annual power production.  

Natural gas is still the mainstay for ERCOT’s generation mix, accounting for 53.2% (256.8 million MWh) in 2019 and contributing 56.8% of the power during the July 13 peak hour in 2020.  Furthermore, during both the 2019 and 2020 peak summer hours, thermal and nuclear power combined provided 86.7% and 81.0% of total supply, respectively.

Texas electricity production by fuel, MWh

 

ERCOT interconnection queue dominated by cleantech

According to ERCOT’s most recent (July) Monthly Operational Overview, published on August 17, 2020, the region’s interconnection queue is flooded with wind, solar, and energy storage projects – 615 projects (121.4 GW) as of July 31, 2020.  Utility-scale solar tops the queue at 75.3 GW, followed by wind at 25.5 GW, and battery storage at 14.5 GW.

Green future bright despite lower price incentives  

Customers benefit greatly by lower market power prices, but with ERCOT’s “energy-only” market, higher price signals are necessary to support future capacity development.  But even with that backdrop, the rapid and tremendous investment in solar, wind, and battery storage augmented by natural gas generation support an even ‘greener’ future for the Texas grid.

Kent Knutson's picture

Thank Kent for the Post!

Energy Central contributors share their experience and insights for the benefit of other Members (like you). Please show them your appreciation by leaving a comment, 'liking' this post, or following this Member.

Discussions

Matt Chester's picture
Matt Chester on Sep 17, 2020 9:42 pm GMT

It's compelling to see Texas renewables thrive under harsh summer conditions, especially with the backdrop of a lot of the issues California had this summer amid heat waves. Do you think the Texas grid demonstrates that it's not simply renewable penetration that created issues in California, but rather other factors? How can CA (and other states) learn from these successes in TX?

Bob Meinetz's picture
Bob Meinetz on Sep 19, 2020 11:38 pm GMT

Kent, why is Texas fossil fuel consumption higher in 2019 than it was twenty years earlier?

I thought the purpose of renewable energy was to reduce carbon emissions. Together with a methane (natural gas) leakage rate of up to 3%, there is no evidence total CO2e emissions aren't worse than they were in 1999.

That's going backwards. And in Texas, more and more it seems,  that's exactly the point.

Matt Chester's picture
Matt Chester on Sep 21, 2020 11:08 am GMT

Together with a methane (natural gas) leakage rate of up to 3%, there is no evidence total CO2e emissions aren't worse than they were in 1999.

Are you saying that the evidence confirms that CO2e emissions are worse than in 1999, or are you simply suggesting the numbers that we track are muddied and untrustworthy? If the former, can you link to a good assessment to read about that? And if the latter, do you have a suggestion for what the numbers should be? 

Bob Meinetz's picture
Bob Meinetz on Sep 21, 2020 4:19 pm GMT

What are the numbers you track, Matt? The numbers I track estimate 2-3% of methane ("natural gas") is leaked, and that methane is 25-86 times more potent then CO2 as a greenhouse gas - making methane significantly worse than coal as a contributor to climate change. By the way, neither number is in dispute; oil companies claim they're working hard to minimize leakage, but they're obviously not working hard enough.

What's the total environmental impact of natural gas vs. coal to generate the same amount of electricity? Let's use an average for both figures to make the following assumptions:

2.5% of methane is leaked
Methane is 68x worse than CO2
The 97.5% of methane burned to generate electricity emits .6 times as much CO2 per unit of energy as coal

Leakage impact + combustion impact = Total emissions impact of methane relative to coal:

(2.5% x 68)  + (97.5% x .6) = 170 + 58.5 = 228.5%

The total climate change impact of using natural gas to generate electricity is 128.5% worse than coal. Make all of the yellow bars in the graph more than twice as long as they are now, and we can assume we're generating considerably more CO2e emissions now than we were twenty years ago.

Natural gas proponents point out (correctly) that mining coal releases methane into the atmosphere too, and mining releases hazardous chemicals (arsenic, mercury, PM2.5 hydrocarbon particulates). Then again, we're not counting the impact of flaring natural gas.

I'm saying existing evidence suggests that when leaked methane is included, CO2e emissions are considerably worse than in 1999. If someone disagrees? Fine - include leakage, and prove that they're not.

Matt Chester's picture
Matt Chester on Sep 21, 2020 9:02 pm GMT

I don't disagree with you, Bob. What's interesting is how much of the research out there seems to mirror back of the envelope here in terms of "well if we assume X, and make a best guess for Y, and look at this time period vs. that period then the answer is so and so." I asked not to attack your point at all, but just because I was curious to see if you had come across an authoritative study more conclusive than the ones I have that come up with similar-ish numbers as yours. In the end, the assumptions appear to move the sliding scale from 'well it's still a little better than coal' to 'well actually it's somewhat worse than coal,' which is to say there's no real 'win' scenario for the gas numbers. 

Bob Meinetz's picture
Bob Meinetz on Sep 22, 2020 8:58 pm GMT

You're right, Matt, and I wouldn't even go there if so many weren't hanging on to the idea "gas generates half the emissions of coal."

When the margin of error is so big for escaped gas, it's a bit like trying to determine the social impact of carbon. You can game those inputs to show virtually any output you like.

Robin Duquette's picture
Robin Duquette on Sep 21, 2020 5:32 pm GMT

While this is good news for emissions, economically, it hurts renewable reinvestment economics. Indeed, the average day-ahead revenue associated with the on-shore wind over the last 12 months is less than $20/MWh and even below $10/MWh for wind generation in Panhandle.

Joe Deely's picture
Joe Deely on Sep 21, 2020 7:11 pm GMT

Robin,

Do these same numbers - $20/MWh and $10/MWh - apply to NG and coal?

Robin Duquette's picture
Robin Duquette on Sep 22, 2020 1:06 am GMT

Joe,

Because gas-fired plants can run only when their margin is positive, their average revenue should be higher than wind power. For instance, for the same period, a CCGT located in ERCOT West has an average revenue of $30/MWh versus $17/MWh for wind. However, the CCGT has a variable cost of $10.50/MWh (gas from Waha is cheap!), leading to a net revenue of $19.50/MWh.

I don't have the numbers for coal-fired plants but their average revenue should be higher than wind power too.

Joe Deely's picture
Joe Deely on Sep 23, 2020 3:53 pm GMT

Thanks - if I were to assume that coal average revenue was the same as CCGT and costs substantially higher then that would imply that most if not all coal plants in TX are barely breaking even... sound about right?

Also, wondering of you have looked into implications of 5-10GW of storage being added in TX...

Robin Duquette's picture
Robin Duquette on Sep 23, 2020 7:40 pm GMT

Coal price (i.e., PRB) is actually cheap (about $0.65/mmBtu) but transportation can make it more expensive than natural gas. The issue with coal plants is there are less flexible and, thus, can have lower average revenue price than their CCGT counterparts.

Batteries of 2h duration appear to be profitable in ERCOT today if they are actively offered in the day-ahead capacity market. However, longer duration requires a lower price in $/kWh to be profitable. If Tesla is right on getting to $100/kWh in 3 years, we should definitely expect more batteries to be installed. You can check this dashboard (under ERCOT) for an assessment of a battery versus a CCGT based on the last 52 weeks.

Joe Deely's picture
Joe Deely on Sep 24, 2020 12:23 am GMT

Batteries of 2h duration appear to be profitable in ERCOT today if they are actively offered in the day-ahead capacity market. However, longer duration requires a lower price in $/kWh to be profitable

It makes perfect sense to add a battery system today with short duration but engineer it so that it is easy to expand in the future.

This is exactly what LS Power did with their recent 250 MW Gateway storage project.

"We built Gateway as a shorter duration project, but we built it so we had room in the buildings... to expand that capacity when we had customers for that capacity," King said.

Matt Chester's picture
Matt Chester on Sep 24, 2020 10:48 am GMT

Agree in what you're both saying-- a lot of the poo-pooing of grid-scale batteries is more or less 'why bother, they can't replace baseload generation or let us go to 100% intermittent renewables,' but that's putting the cart before the horse. The fact that we can have a market for large-scale energy storage on the grid today (without any subsidies, mind you) is great news for today and signal of even better future to come for energy storage as that market will help foster continued progress in the tech

Gary Hilberg's picture
Gary Hilberg on Sep 24, 2020 5:04 pm GMT

Joe - the challenge for batteries will be how often these events occur, many days there is very little difference in the pricing maybe even less than the losses associated with the AC to DC to AC conversion.  Behind the meter there is potential to reduce the transmission charges by managing a user's peak load (4CP).  There are wholesale ancilliary services, but pricing varies and may not support project financing.  

Bob Meinetz's picture
Bob Meinetz on Sep 29, 2020 9:30 pm GMT

"The fact that we can have a market for large-scale energy storage on the grid today (without any subsidies, mind you) is great news for today..."

Matt, ask an engineer, ask a physicist: from an environmental perspective storing grid energy in batteries has never been "great news" and never will be.

Any mode of energy storage on the grid, batteries included, only increases emissions. Not sometimes - all the time. And batteries increase emissions a lot - on average, 250kg (551 lbs) up to 407 kg (897 lbs) per megawatthour:

The “round-trip efficiency” of energy storage — the amount of energy it releases relative to the amount put in — ranges, depending on the technology, from around 40 to 90 percent.

Let’s take, for representative purposes, 80 percent, a relatively optimistic assumption for the efficiency of lithium-ion batteries. For every 1 megawatt-hour put in, 0.80 megawatt-hours comes out.

That means, if it is stored along the way, getting 1 MWh to the customer requires generating 1.25 MWh. The more energy that gets stored, the more generation has to increase to compensate for the round-trip losses.

Batteries have a dirty secret

Now efficiency activists sweat over every kWh they're able to save by replacing incandescent bulbs with LEDs, insulating doorframes, etc, but have no problem wasting 10-60% of an entire service area's energy by storing it in batteries. It would be funny, if it wasn't so effing stupid.

What began as a Hail Mary pass intended to solve the intermittency of solar and wind has only made emissions worse (that's not Bob talking - that's science).

Gary Hilberg's picture
Gary Hilberg on Sep 22, 2020 1:27 pm GMT

Kent - as always great data and analysis, thank you.  In ERCOT our analysis has always been focused on the peak demand periods due to most of generation being flexible and as such barring failures and lack of Demand Side Management the price ramps with peak demand.  Watching ERCOT pricing over the year, we are seeing many more periods of very high pricing away from the peak summer periods.  I don't have the generation data to confirm, but it would seem to me that with a greater amount of non-flexible generation when the wind stops or there is lots of cloud cover, we will have periods of high price due to lack of responsive generation.  Does your data set support this hypothesis?  As a consumer in ERCOT, any user now has the ability to see pricing real time and many have financial reasons to respond, so this increase in DSM is also reducing peak pricing.  

Joe Deely's picture
Joe Deely on Sep 26, 2020 8:44 pm GMT

Joe - the challenge for batteries will be how often these events occur, many days there is very little difference in the pricing maybe even less than the losses associated with the AC to DC to AC conversion.  Behind the meter there is potential to reduce the transmission charges by managing a user's peak load (4CP).  There are wholesale ancilliary services, but pricing varies and may not support project financing. 

Gary,

Does this change as the remaining 19GW of coal are retired? Solar will be killing coal on ERCOT over the next 4-5 years.

Gary Hilberg's picture
Gary Hilberg on Sep 28, 2020 5:26 pm GMT

Joe - I am sure that there will be change, but on the variable generation side, natural gas will compete with Solar, and if coal goes away faster, before renewable can be built, the capacity factor for NG goes up and more NG survives/is built.  I have trouble seeing how we keep all the base load usage online with limited base load generation so we have to have something like nuclear - alway on AND natural gas to come on quickly to backfill renewables.  Once we have the NG plants there (need to be able to backup renewables) - burning a modest amount of NG will be more economic than long term energy storage (of any type) with today's technology and costs.  The emissions profile will not be significant compared to current profile and the costs will be better.  The fixed operational costs associated with NG plants are much lower than coal and remember that we need natural gas for heating in the winter.

Bob Meinetz's picture
Bob Meinetz on Oct 1, 2020 6:54 pm GMT

"Solar will be killing coal on ERCOT over the next 4-5 years."

Solar can generate electricity at night now, Joe? News to me.

Seems like Texans might use electricity at night sometimes, when solar is worthless. When coal might make the difference between Texans having air conditioning, or sweating themselves to sleep. Right?

Joe Deely's picture
Joe Deely on Oct 2, 2020 3:54 am GMT

Bob,

You are correct - solar generation disappears after the sun sets. 

Note: overall generation also declines after the sun sets and temps fall in TX.

I assume you are aware that wind is now a larger source (XLS file from ERCOT) of generation in TX vs coal. However, perhaps you unaware that this wind generation tends to pick up in late afternon and continue throughout the night.

With competition from growing wind - coal generation at night has declined dramatically in TX over the last few years. So, currently coal is a lot like solar, with its generation peaking during the day and declining at night - often to less than 5GW.  

Because of this yoyo generation the CF for the remaining 19 GW of coal in TX has dropped to 45% for the first 7 months of 2020.  This is despite the fact that 4GW of coal were retired in TX in 2018.

Now along comes solar - currently peaking at about 3.5GW midday on ERCOT. By next year at this time it will be 7.0 GW at midday and a year later it will be over 10GW.

Do you see how that works? We have increasing wind at night - meaning coal usage at night will be dropping into low single digits(GW). Then we have increasing solar during the day, meaning that coal usage during the day will drop into the low single  digits(GW). 

Plus, we haven't even begun to talk about what happens when solar capacity in TX moves past 20GW and 10GW of storage is added onto ERCOT.

Goodbye coal.

Hey Kent - we are now at 22 comments. I'm guessing it will go higher.

Bob Meinetz's picture
Bob Meinetz on Oct 2, 2020 1:56 pm GMT


As you can see by the EIA graph above, natural gas consumption increases when coal decreases - the two graphs are mirror images of each other. Gas is replacing coal in Texas, not wind, because wind can't replace coal - gas is dispatchable and wind is not.

That will never change - electricity customers pay for electricity on demand, not at the whims of nature.

Solar in Texas is insignificant, a blip on the radar:

The contribution of batteries is even less significant than solar. What about their potential for the future?

Much attention has been given to battery installations "paired" with solar or wind farms, without any indication whether such installations charge from the DC output of the farms to which they're adjacent, or directly from the grid.  So I emailed EIA and asked them. They replied promptly, indicating they don't know. They have no idea, and economics would suggest batteries would be more profitable charging from the grid, where they can be used anytime for either peak or ancillary services. In that case they're creating even more emissions than they're preventing.

In our many discussions, Joe, you've made it clear immediately addressing climate change isn't that important to you. You seem to feel we can wait and see whether renewables replace coal, or gas, or anything else. We all make our own ethical judgements on energy policy, and arguing about them is pointless. But it's obvious, from any objective interpretation of past data, that solar and wind have been a profound failure at addressing climate change, both in the U.S. and abroad, and will continue to fail for the foreseeable future.

Nuclear has failed at addressing climate change in the U.S., but it's been an unmitigated success in France, Belgium, and Sweden. Because its limitations are not technical, but ones of politics and public perception, I'll continue supporting it as long as my belief in its potential is supported by data. When it's not, I won't.

Joe Deely's picture
Joe Deely on Oct 10, 2020 6:54 pm GMT

Bob,

As usual love when you put things down in writing...

"Solar in Texas is insignificant, a blip on the radar:"

Let's follow along to see how solar does in TX. So far this year, solar is at 5,943 GWh vs 43,741 GWh for coal. So about 1/7 - let's see where things stand next year.

As for your comment on nuclear:

 "but it's been an unmitigated success in France, Belgium, and Sweden. Because its limitations are not technical, but ones of politics and public perception, I'll continue supporting it as long as my belief in its potential is supported by data. When it's not, I won't."

France - has retired two nuclear reactors this year. Production from nuclear in France this year will drop significantly. Luckily the drop in nuclear is being picked by by new wind and solar.

Sweden - retired Ringhals-2 last December and Ringhals-1 is scheduled to retire this year. Wind generation is booming in Sweden and will pass nuclear this decade.Belgium - like France and Sweden nuclear share is declining.

Again, the decline in nuclear generation is being replaced by wind.  Belgium named world’s 4th largest producer of offshore wind energy

 

In none of these countries is nuclear helping to improve climate change - the opposite is happening - nuclear generation is regressing. All 3 countries you mentioned are in fact, great examples that your belief is not supported by data.

Bob Meinetz's picture
Bob Meinetz on Oct 5, 2020 7:56 pm GMT

Joe, the fact is that nuclear already has limited climate change.

France has the lowest per-capita emissions in Europe - by far. It went from among the highest to the lowest in 16 years. Forty years ago.

With nuclear it's possible. You have no evidence whatsoever it's possible with solar and/or wind. None.

Kent Knutson's picture
Kent Knutson on Sep 28, 2020 9:02 pm GMT

Thank you to everyone for providing comments.  Having 17 is certainly a record for one of my posts on the EC blog.  It's increasingly more difficult for large coal power plants running at low capacity factors to stay operating in ERCOT or anywhere in the U.S.  Dispatchable natural gas power fills the niche as long as gas prices stay competitively low. For the next several years, it makes sense to grow solar, wind, energy storage, and even natural gas power.  The recent move to develop gas power plants that can burn green-hydrogen is fascinating, and, if cost competitive in the future, could be a game changer.  Thanks again for all your comments.     

Gary Hilberg's picture
Gary Hilberg on Sep 29, 2020 5:24 pm GMT

You started the ball rolling with good analysis - thanks Kent.

Get Published - Build a Following

The Energy Central Power Industry Network is based on one core idea - power industry professionals helping each other and advancing the industry by sharing and learning from each other.

If you have an experience or insight to share or have learned something from a conference or seminar, your peers and colleagues on Energy Central want to hear about it. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful.

                 Learn more about posting on Energy Central »