Renewables Shine Big and Bright in Texas
Remarkable growth in solar and storage deployments in Texas in the past year keep pushing renewable energy records higher into 2025 and beyond
Hello, Fynn here. I’m an engineer, technology consultant, and renewable energy nerd. My aim here is to share resources and musings (with occasional wordplay) as I write about the world of energy and the generational shift that is underway in energy technology, policy, and markets here in Texas and beyond. I want to make it relatively accessible for those of us who are new to the energy field while bringing insights that I’ve gathered through my learning journey.
Texas keeps setting national solar generation records at a blistering pace.
In just 2 weeks, solar generation jumped 2 gigawatts from 22.3 GW on February 2nd to 24.3 GW on February 16th. Per gridstatus.io, that is the largest/fastest solar generation increase in ERCOT history!
I wrote about this and other renewable energy trends with a retrospective on 2024's record renewables deployment in Texas, and a look ahead to what is already a record setting 2025 and beyond, including national and global trends, load growth and capacity projections, some brief explainers, and a few of my own hot takes as well.
12 GW of Texas Solar and Storage Went Live In 2024
ERCOT just dropped its Commercial Markets Update and there are some pretty impressive trends showing up in the 2024 Year In Review:
Over 13 gigawatts (GW) of new generation capacity was installed in 2024 (up from 10.5 GW in 2023)
Over 90% of the new Texas gen was renewable energy! (solar, storage, and wind); the vast majority of that solar and storage (~7 GW and ~5GW, respectively):
Solar + storage generation provided life-saving relief, preventing summer outages in 2024 when thermal generation (gas, coal, nuclear) outages were higher than expected
(T)exponential Growth: Solar & Storage To Dominate 2025
Total utility solar capacity in Texas is poised to pass total wind capacity in 2025, as highlighted in Nat Bullard’s annual presentation on energy and decarbonization trends. Near exponential growth of solar deployment contrasts with relatively linear growth in Texas wind generation dating back 25 years. Remember, Texas leads the nation in wind generation capacity with 40+ GW and over 17,000 turbines. The economies of scale achieved by the utility scale solar industry have had an obviously powerful effect, in concert with a relatively speedy regulatory framework in the ERCOT grid known as “connect and manage” where interconnection process is 8-30 months depending on system size, allowing ERCOT to bring more generation online than any other grid operator:
This trend is reflected globally, again from Nat Bullard / BloombergNEF:
For the first time, over half a terawatt of solar deployed in a single calendar year!
That’s an astounding number. BloombergNEF estimates the global solar manufacturing capacity at 1.2 TW, and polysilicon production capacity in 2024 around 900 GW. To see roughly half of that capacity reach installation is an impressive global achievement. The bulk of installations are still owned by China, but rapid growth in emerging markets such as India and Pakistan, combined with strong growth in US and European markets bode well for future growth, despite geopolitical and tariff-related headwinds.
Zooming back in to Texas, per ERCOT:
20 GW each of utility scale solar and storage projects scheduled to connect to the grid in 2025
83% of the generation projects in the interconnection queue are solar or storage projects
As Doug Lewin writes, not all of those projects will come online, but likely more deployment records will be set this year, and storage may soon surpass solar in new energy resources built on the ERCOT grid.
Energy storage, also known as Battery Energy Storage Systems (BESS) have played a key role in ERCOT’s ancillary services and increasingly in 2024, energy arbitrage: discharging daily on morning and evening demand peaks when solar is ramping up and down respectively, and charging during the day when solar energy is abundant and prices are low (also at night, when demand is low and wind tends to be strong):
This trend looks set to grow as more storage connects to the grid in 2025 and beyond, providing valuable ballast to the system and shifting off peak solar/wind production to times of scarcity and peak demand, acting as a dispatchable asset and helping to smooth the net load duck curve.
Renewable Generation Records Keep Falling
If you go to gridstatus.io Record Tracker tab, you can see all that new generation showing up in 2024:
On December 29, 2023 the Maximum Solar record was set at 13,929 MW, the high water mark for that year.
By July 16, 2024, the record had pushed to 20,004 MW, a 44% increase in only 7 months!
The all time record was just set on February 2, 2025 at 22,305 MW — good enough to meet 48% of load!
Edit: On 2/16/25 that record was just re-broken, set at 24,307 MW, up 2 GW in 2 weeks! An absolutely blistering pace.
For reference, PJM, MISO and CAISO each have yet to break 9 GW!
From a total renewables perspective, ERCOT reached a record of 39 GW on January 24, 2025 which is highest in the nation by a significant margin.
While BESS is far behind solar in total capacity, it’s still setting records and set to grow twice as fast as solar deployments in 2025:
Sometime this year renewable generation records could surpass 50% of the maximum load record of ~86 GW set this past August, which is a significant milestone on the path to a low carbon grid.
Peak Load Set To Double, Capacity Needs To Triple?
Of course the challenge remains: while renewable deployments are growing, so too is load, setting progressive records each summer. Looking ahead, ERCOT is forecasting load growth far beyond what we have ever seen before:
Driven by electrification, data centers, economic growth, and a warming climate, peak summer demand is projected to essentially double within the next 10 years according to ERCOT’s forecast.
In December, ERCOT released their Long Term System Assessment which simulated three scenarios for future load growth out to 2039: current trends, high large load adoption, and high load growth with environmental regulations:
Currently the total installed capacity in ERCOT is around 170 GW, but only a portion of that is available to generate energy at any given point in time due to thermal outages, maintenance, curtailment, weather conditions, etc. So it’s imperative to have a significant margin of generation capacity above peak load at any given time, something known as resource adequacy (RA).
The study projects 228 to 500 GW of total net capacity across the three scenarios, offsetting 25 GW of old coal and gas plant retirements, essentially tripling the current generation capacity in ERCOT in 15 years:
Utility scale solar has the largest share in all 3 scenarios: 62 - 158 GW
Wind encompasses a more modest range: 55 - 83 GW
Storage runs similar to wind: from 26 - 88 GW
Combustion turbines (gas) run the largest range: 21 - 112 GW
Once again, solar, wind, and storage play a dominant role in all scenarios, driven mostly by economics (they’re just cheaper than fossil generation) and project timeline (they’re much faster to build, mostly due to gas turbine supply chain constraints) and this is reflected in the current interconnection queue composition, dominated by solar and storage.
However, net load ramping needs increase significantly with greater renewable penetration due to the variability of energy production. Storage can fill most of those needs at adequate scale but natural gas turbines are also a key resource to fill system needs for minimum inertia as well as net load ramping, which would be steep with high renewable system as the sun sets and solar generation drops but electricity demand stays high, particular in hot summer evenings. In addition, extended periods of low renewable generation preclude battery storage from charging cheaply and require natural gas generation to take on a much larger role.
In terms of the projections, given what we’re seeing on the load growth side (particularly large loads like data centers and manufacturing) as well as generation deployment, the low ends of those projections seem unlikely. If Nat Bullard is right, and even half of the 20 GW of projects in the queue come online, we’ll get close to 50 GW of utility solar by the end of this year, and at that pace we would hit 62 GW in the next couple years.
If we assume 10 GW of solar deployed per year starting in 2025 (remember we just did 7 GW last year and there are already 2-3 GW online in 2025), by 2039 there could be 150 GW of new solar capacity, and a total of nearly 200 GW! That’s not out of the realm of possibility although it’s quite unlikely that pace is completely sustainable for 15 years. If you assume 7 GW per year, you get a total of around 150 GW, in line with the high end of the LTSA projections, very doable.
For storage the starting point is lower, around 10 GW capacity currently, but assuming similar annual deployment numbers of 5-10 GW, by 2039 you could get 85 - 160 GW of total storage capacity. Very doable and in line with projections.
As we’ve seen, wind generation is on a slower growth curve but could reasonably double its current capacity in 15 years to reach the high end of projections around 83 GW, coming out to a clip of 2-3 GW per year, right in line with the current growth rate.
The good news is we’re already deploying enough renewable energy on an annual basis to meet even the high ends of the ERCOT capacity projections!
But that’s only one piece of the puzzle…
Transmission Is Key To The Mission
Notably, the LTSA study did not include the high voltage transmission projects currently under consideration by the PUC, including 345 kV and 765 kV lines, since those projects are still in the planning phase and transmission projects can take over a decade to build from planning to completion. But as the study highlights, transmission is a major constraint on the system currently, especially for importing plentiful West Texas solar and wind to the demand centers in north, central and eastern Texas. More transmission is needed to reach the renewable penetrations ERCOT simulated in the LTSA. More transmission will be built, as with most things in Texas: faster than elsewhere, but there is a real risk to the grid and to reaching a lower carbon grid if significant investments are not made in the very near term to build out transmission in Texas.
However, this also underscores the need for more generation to be built closer to the load, which is a primary benefit of distributed energy resources (DERs), another key growth area in Texas energy. More on that in another post.
The Case To Keep Building Renewables Is Strong
Historically, the main criticisms of renewable generation are that it’s variable/intermittent and non-dispatchable, which are valid. Wind production tends to be seasonal: most productive in spring and fall shoulder seasons, and least productive in summer when demand is highest. Increasing buildout of solar helps to fill the gap; even on a cloudy day production is significant and in sunny Texas summer when daylight hours are long and the sun is high, production is near peak. From a grid perspective, overbuilding renewable generation solves a lot of these issues because even on a relatively cloudy, calm day you’re able to supply the majority of load. This may seem wasteful because the rest of the time you’re producing more power than you need, until you realize that 60% of energy used to produce thermal generation is lost as waste heat, not to mention the carbon and particulate emissions that are totally externalized to the atmosphere, environment, and our lungs at no cost currently to the companies producing them.
That’s why BESS is a game changer. It’s highly dispatchable and flexible, responding in milliseconds to supply power to the grid (particularly valuable when combined with variable renewable output — clouds pass over or wind speed varies). Additionally, storage absorbs excess renewable generation on the grid: all that energy lost as heat in fossil fuel generation? In a well designed renewable grid with adequate interconnect and transmission, BESS soaks up those excess electrons to be fed back on to the grid when needed.
Overbuilding storage is another obvious thing to do: that energy will eventually be needed on the grid, though price signals may not align perfectly and transmission constraints are inescapable. To hedge against those risks, co-locating loads with solar and wind provides alternate off-takers and revenue streams when the grid is saturated or transmission congestion prevents exporting energy to the demand centers. Known as curtailment, it’s a major issue for west Texas solar and wind projects particularly those not eligible for production tax credits (PTC), a mechanism from the 2022 Inflation Reduction Act to incentivize renewable development. Strategic siting of BESS projects can help to capture excess renewable generation and redistribute energy to stressed areas of the grid, but it all hinges on adequate transmission infrastructure, as the LTSA study highlights.
Residential storage (and solar) is another growing resource and fills much the same purpose on the distribution side while providing backup power and resiliency for homeowners when the grid goes down. Virtual Power Plants (VPPs) aggregating many small assets in to a large dispatchable grid asset are easily one of the coolest developments in energy technology in recent years, more on that in a later post. For now, I recommend to check out the DER Taskforce to learn more and join the vibrant community they have cultivated. Texas is lagging behind other states on this front, despite having a pilot project for the past few years. 2025 could be the year where the potential is really unlocked!
Past Is Prologue, Renewable Energy Is The Future
When I look at the current ERCOT fuel mix, and the historical trend a few things seem clear:
Renewables will continue to grow in share: thanks to superior economics and shorter project timelines ultimately yielding a low(er) carbon generation portfolio
A diverse generation portfolio is a strength, not a weakness: while renewables are clean and keep prices low, thermal/fossil generation with its spinning turbines and high dispatchability play a valuable role in grid stability and reliability
For the foreseeable future, thermal/fossil generation will be in the mix: for reliability, stability, inertial and other reasons stated above. Ideally advanced geothermal technology reaches commercialization and scale and provides the same services as traditional thermal generation, without the emissions.
The project then, is to reduce those emissions as much as possible. There are many ways to do this. As Dr. Michael Webber likes to say, “do your best, and clean up the rest.”
Austin Energy’s REACH program has been fairly successful in reducing the carbon footprint of the Fayette Coal Plant by pricing in emissions to the ERCOT wholesale bid prices. However, Austin Energy remains hopelessly addicted to the coal plant that was scheduled to exit years ago, in part due to a complex ownership structure where Austin Energy and Lower Colorado River Authority (LCRA) literally own shares of the same turbines (and LCRA has no intention of shutting Fayette down), and also due to the liquidity hedge it represents: Austin Energy made $11 million in one day from Fayette in 2023!
This example is illustrative of the challenges and complexity of decarbonizing infrastructure and industry that was built decades ago to burn carbon and generate electricity as cheaply as possible.
My hope, and growing conviction, is that the market will continue to drive towards a clean, reliable, resilient, and secure grid. Only time will tell, but all energy roads run through Texas and I’m excited to be at the epicenter of a generational shift in energy that has the potential to change the world. I hope to be a small part of that and help to tell the story.
Predictions Are Usually Wrong; I Just Have Questions?
As Niels Bohr ostensibly said, “predictions are hard, especially about the future.” With that said, here are some questions I have that definitely aren’t predictions but just things that I’m thinking about as we move into the energy future:
Will load flexibility in the future enable load to follow variability of renewable generation more closely, thus reducing the need for “firm, dispatchable” thermal generation?
Will energy storage buildout be much higher due to cost curve improvements and feed the minimum inertia and ramping needs of the grid sufficiently, reducing need for thermal generation?
Will advanced geothermal energy scale up well enough (no pun intended) to replace fossil thermal generation's role in stabilizing the grid?
Will long duration energy storage reach a scale needed to cover the seasonal edge cases where solar and wind production are low for days (cloudy and stable air masses) and short duration storage can’t compensate?
Thank you for reading! Let me know your thoughts.
Special thanks to Doug Lewin, one of the leading voices in Texas Energy. His Texas Energy and Power Newsletter is a must read for all energy nerds, and I referenced several of his posts to write this. Go subscribe!
Special thanks to Corey Pudhorodsky who has been a key resource in my clean energy journey and writes eloquently about climate and energy as well. Go subscribe!
This is a helpful read for anyone wanting to get caught up with the sate of the energy transition in Texas! I'll be recommending it to others and looking forward to future posts where you dive into other topics.