Tag: Weather-Smart forecasts

Why We Nailed Our July ERCOT Price Forecast

(When Others Thought We’d Miss)

Authored by Son Phan, Research Scientist, REsurety

Son Phan
Research Scientist
REsurety

At REsurety, our research and power markets team is dedicated to modeling energy prices, project generation, and emissions impact. The team is interdisciplinary: we have experts in power markets, statistics & analytics, meteorology, and grid operations.

Why do we need such a deep bench of experts? Because forecasting electricity prices is notoriously complex. These values determine what projects get built, sold, and invested in – months before we’ll know whether the wind will blow or the sun will shine. It’s high stakes, and our goal at REsurety is accuracy.

If you’re an energy buyer, we know better forecasts mean better budgets – helping you to engage internal stakeholders, build confidence in your portfolio strategy, and plan for future investments.

If you’re an investor, better forecasts help reduce uncertainty around whether projects will hit their rate of return or lead to stable, long-term yields.

And if you’re a trader, credible data means hedge providers can more accurately price offtake agreements. Improved pricing means better risk management with an eye towards the bottom line.

With so much in play, we take this job very seriously, and invest resources internally to focus on providing the analytics our clean energy customers need to lead. Often, it pays off: in July, for example, REsurety predicted ERCOT prices in the mid-$30s per MWh – and we were only off by one dollar. That doesn’t seem all that impressive unless you compare to market forwards: this spring, when we made this prediction, the market forecast predicted prices around $60/MWh – double actuals. Without REsurety data, buyers may have assumed twice what they received in revenue.

So, how were our forecasts that accurate? It boils down to our unique approach and our commitment to a weather sensitive, fundamentals-based model.

How We Optimize Our Models: Customer-First Thinking

Let’s take a step back to talk about our customers for a second. Our customers are looking to buy, sell, or trade clean energy. Take this example: a buyer is looking to enter into a PPA from a solar farm in their region, with a specific budget and generation capacity in mind for the year. When that customer uses REsurety price forecasts, they are not only looking for good data to value the solar power for sale right now against other solar assets, but also looking to compare against a baseline price provided by their grid operator – i.e., if they just pulled power from the grid, at whatever energy mix the grid operates at, and didn’t make the clean power investment at all.

Whether the purchase of solar power – from that specific solar asset – will “pencil out” is based on what its electricity is expected to sell for in the future. This price determines their clean energy buyer business case, and determines key financial metrics like payback period and cashflow volatility. For some corporations, if the renewable energy isn’t at price parity with traditional sources offered by the local grid operator, they won’t be able to buy due to budget constraints. Other companies have more flexibility, but often, our clients are working hard to justify their clean energy purchasing year to year, just like every other department at a company.

So with that in mind, our primary goal is to provide an accurate distribution of clean energy prices with actionable insights for our clients, recognizing their goals. We are not incentivized to inflate our prices for one side or another; we’re incentivized to help our customers keep making, using, and buying clean energy.

Our Fundamentals-Based Approach: The REsurety Difference

Forecasting electricity prices is tricky. In a grid like ERCOT, with significant intermittent energy generation sources from solar and wind, the task is even trickier. Weather, a significant and inherently difficult variable to account for, is a main driver of price forecasts.

Many traditional methods, like time-series and statistical models, often fall short. They struggle to meaningfully incorporate extreme weather events which are expected but only happen very rarely. This weather variability issue is exacerbated as the volatility and fundamentals of the market change as it grows. For a dynamic market like ERCOT, which is prone to short-term price spikes and has cases of extreme weather events such as 2021’s Winter Storm Uri, statistical models are particularly ill-suited.

Instead of relying on finding a causal signal in historical data, we employ a sophisticated fundamentals model. This model simulates how a market operator would dispatch supply to meet demand, providing a realistic view of market dynamics. While our point estimates don’t aim to perfectly predict every short-term spike, we acknowledge their possibility through our Weather-Smart distribution of prices. This distribution allows us to illustrate a range of potential outcomes based on various weather scenarios.

Our Advantage: Calibration and Pragmatism

Our forecasts are built on a foundation of robust data and expert analysis including publicly available market data, such as ERCOT’s own forecasts for load and generation evolution, our own market research & expertise, and comprehensive weather data.

This means that we don’t blindly accept forecasted load and capacity growth. Our model is continuously refined as the grid evolves, with improvements focused on areas like transmission constraint accuracy, granularity of generation additions, and impacts of policy changes.

Our advantage lies in our pragmatic approach to calibration:

  • Supply Must Meet Demand: We operate under the crucial assumption that grid capacity will be able to meet demand the vast majority of the time.  This means that our expert team interprets various data points – such as the 300 GW of data centers in load interconnection queues across the country – and, rather than accepting them at face value, judiciously calibrates them to ensure that the result is a functioning power system.
  • Supply will be Built Out in a Realistic Way: We don’t assume that the supply chain can work to instantly build generation to meet unrealistic demand forecasts. Instead, we consider the practical realities of construction and project approval rates. If an ISO, like ERCOT, forecasts an unprecedented demand increase, and historical data shows such rapid build-outs are improbable, we factor that into our projections. We analyze interconnection queues, understanding that only a fraction of proposed projects actually come online.
  • Generation Source Behavior Matters: We meticulously examine the commitment and dispatch of specific generation types under different weather scenarios. For example, if wind saturation increases, we assess whether this realistically leads to a reduction in gas peaker commitment and, consequently, lower prices.

How REsurety’s Accuracy Drives Your Strategy

We incorporate weather variability to capture the short- and medium-term volatility in times of stress for the grid. This pragmatic, data-driven approach empowers you to:

  • Make Informed Decisions: Improve your understanding of when to buy and when to sell energy.
  • Improve Budget Forecasting: Achieve more accurate and reliable energy cost projections, empowering your financial planning.
  • Navigate the Clean Energy Market: Our forecasts help you understand the evolving dynamics of clean energy trading, even if you’re not an “energy nerd.”

At REsurety, we provide our customers with forecasts based on complex energy simulations and power markets expertise, giving them the insights they need to make informed investment decisions and navigate the energy market with confidence.

Want to learn more? Check out more resources from REsurety here.

Why We Nailed Our July ERCOT Price Forecast

(When Others Thought We’d Miss)

Authored by Son Phan, Research Scientist, REsurety

Son Phan
Research Scientist
REsurety

At REsurety, our research and power markets team is dedicated to modeling energy prices, project generation, and emissions impact. The team is interdisciplinary: we have experts in power markets, statistics & analytics, meteorology, and grid operations.

Why do we need such a deep bench of experts? Because forecasting electricity prices is notoriously complex. These values determine what projects get built, sold, and invested in – months before we’ll know whether the wind will blow or the sun will shine. It’s high stakes, and our goal at REsurety is accuracy.

If you’re an energy buyer, we know better forecasts mean better budgets – helping you to engage internal stakeholders, build confidence in your portfolio strategy, and plan for future investments.

If you’re an investor, better forecasts help reduce uncertainty around whether projects will hit their rate of return or lead to stable, long-term yields.

And if you’re a trader, credible data means hedge providers can more accurately price offtake agreements. Improved pricing means better risk management with an eye towards the bottom line.

With so much in play, we take this job very seriously, and invest resources internally to focus on providing the analytics our clean energy customers need to lead. Often, it pays off: in July, for example, REsurety predicted ERCOT prices in the mid-$30s per MWh – and we were only off by one dollar. That doesn’t seem all that impressive unless you compare to market forwards: this spring, when we made this prediction, the market forecast predicted prices around $60/MWh – double actuals. Without REsurety data, buyers may have assumed twice what they received in revenue.

So, how were our forecasts that accurate? It boils down to our unique approach and our commitment to a weather sensitive, fundamentals-based model.

How We Optimize Our Models: Customer-First Thinking

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Blog Post: Q2 2025 Weather-Smart Fundamental Forecasts Now Available

Author: Jennifer Newman, VP, Research, REsurety

Jen is photographed at NREL’s National Wind Technology Center in Boulder, CO. 

I am excited to share that our Q2 2025 Weather-Smart Fundamentals Forecast release is now available in REsurety’s CleanSight platform. Since 2022, our Weather-Smart Fundamentals Forecasts have helped customers better understand the connection between weather, market fundamentals, and project value. 

With our tools and services, customers can evaluate clean energy projects under expected conditions, stress test downside risk, and identify potential upside. They can build and track portfolios that help mitigate correlated risks — and measure the carbon impact of clean generation, storage, and consumption based on location, timing, and grid dynamics.

In this quarterly installment, we see prices remain relatively flat in the near term, but begin rising in the mid to long term as large new loads put added strain on the system.

Before jumping into the details of our latest forecast, it’s worth revisiting the fundamentals that make such insights possible.

What is a fundamentals model, and why are we using it?

My team’s goal is to forecast how power prices could evolve over the next 20 years, and we’re doing that with a fundamentals model. This means taking all the components that impact price formation — supply, amount of wind or solar generation, gas plant capacity, system demand, the constraints around how electrons move around — and solving for how to meet the region’s load at the least cost possible. It’s the same logic that underlies real-world power markets. The fundamentals model simulates those dynamics to predict future power prices.

Weather-Smart comes in because we don’t just do this simulation for typical weather conditions — we look at 40 years of weather variability and input that into our model to get a distribution of potential weather outcomes. That’s really important because weather can have a big impact on power prices. 

For starters, if it’s really hot in the summer, or really cold in the winter, demand is going to be higher, which tends to drive up the price of electricity. Weather also impacts the supply side, especially when renewables are involved. If it’s really cloudy or if it’s not very windy, then you’re not going to have as much wind or solar generation, and that will impact prices as well. Our Weather-Smart fundamentals modeling brings together all that weather variability along with market fundamentals to predict prices in the future.

From there the name of the game with forecasting prices is forecasting load growth. Most of the markets that we forecast — primarily ERCOT, MISO, and PJM — are expecting a lot of data centers to come online in the next 10 to 20 years, which will dramatically increase load. Many of these markets have not seen a ton of load growth year over year, so this is going to be an almost exponential increase in the amount of load on the system. They’re also expecting to bring more capacity online, including a significant amount of new renewables, along with gas and storage. 

Testing the limits of load growth

An important challenge is to determine if load forecasts are realistic. Do we think that all these data centers will actually come online? And if so, how can we build up the capacity to serve the load while avoiding rolling blackouts? 

In nearly all cases we erred on the side of making downward adjustments to ISO-provided load forecasts, to reflect a) more realistic rates of load growth and b) capacity build-out based on historical trends. We’re seeing many markets moving toward more solar now that it’s relatively cheap. This will cause the value of solar to decrease in a so-called cannibalization effect, where the more and more solar you get on the grid, the less valuable it becomes. Meanwhile as all that solar competes against other solar projects, bringing down energy prices, wind can get a positive edge.

Wind tends to be stronger at night, and as solar generation ramps up during the day, it pushes high prices into the evening. Wind can take advantage of that shift — capturing those higher prices and becoming more valuable as a result. Consequently, we’re starting to see wind value recover in markets that have historically low wind capture rates, such as ERCOT and SPP.
In some markets, we even see brief morning price spikes before solar kicks in, especially when wind has already tapered off — and storage is often well positioned to benefit from those early high-price hours too. 

More broadly, we closely track movements across these markets with the goal to produce the most realistic forecasts possible. We’re focused on what we think is realistic, while also showing the variability around that. This includes weather-driven variability, as well as scenarios based on different gas price assumptions. We provide both high and low gas scenarios to show how prices might respond, since gas plays such a major role in shaping the price of power.

Ultimately our goal is to reflect the most likely outcomes, while also accounting for the uncertainty built into both the weather and the fundamentals.

Want to learn more? Find more information in our Weather-Smart Fundamentals Modeling brief

Ready to dive into the Q2 2025 numbers? Customers, log in to CleanSight

DISCLAIMER: This blog post contains information related to REsurety and the commodity interest derivatives services and other services that REsurety provides. Any statements of fact in this presentation are derived from sources believed to be reliable, but are not guaranteed as to accuracy, nor do they purport to be complete. No responsibility is assumed with respect to any such statement, nor with respect to any expression of opinion which may be contained herein. The risk of loss in trading commodity interest derivatives contracts can be substantial. Each investor must carefully consider whether this type of investment is appropriate for them or their company. Please be aware that past performance is not necessarily indicative of future results.

All information, publications, and reports, including this specific material, used and distributed by REsurety shall be construed as a solicitation. REsurety does not distribute research reports, employ research analysts, or maintain a research department as defined in CFTC Regulation 1.71.

Blog Post: Putting Our Forecasts to the Test

Continually providing value to our customers

Authored by Ryan Gao, Senior Research Associate, REsurety

Ryan Gao
Ryan Gao
Senior Research Associate

Background

At REsurety, our Weather-Smart forecasts provide customers with hourly prices and carbon impact data over the coming 20 years. These hourly forecasts are provided across a variety of weather conditions based on the past 40 years as well as five different market fundamentals scenarios. As of the end of 2023, we have made Weather-Smart forecasts available across all seven deregulated ISOs in the United States. To assess the quality of our Weather-Smart forecasts, we put our forecasts through a reality check and compared how they were performing for the first half of 2024 against observed prices and market forwards. This comparison indicated that the forecasts are fundamentally sound and highlighted the importance of providing forecasts across a variety of weather and fundamentals scenarios. Specifically, the Q4 2023 Low Gas scenario forecast produced a very close price prediction, largely because the gas price inputs used for the first half of 2024 were very close to the realized gas prices. Overall, our forecasts provide a wide variety of weather conditions and different fundamental scenarios, which deliver immense value to our customers by reflecting the uncertainty inherent in price predictions.

Monthly ATC Power Price Comparison

A closer look at the monthly around-the-clock (ATC), or average, power prices has shown that our forecasts in the Baseline fundamentals scenario, depicted in the red curves here, are lower than the OTC Global Holdings (OTCGH) power forwards, depicted in the purple curves. While REsurety’s Baseline predictions were lower than the OTCGH power forwards, both REsurety’s Weather-Smart forecasts and the OTCGH forwards were higher than the observed ATC prices during most months in the first half of 2024. However, our Baseline predictions are actually closer to the observed ATC prices. With that said, our forecasts were lower for a good reason. When considering why both our forecasts and the OTCGH power forwards were higher than the actual observed ATC prices, the biggest driver is gas prices. Back in 2023, the predicted gas prices for the first half of 2024 were significantly higher than what was actually realized. This was driven by a variety of factors including the geopolitical development in Europe and also the outlook for more extreme weather conditions based on what took place last year. However, actual gas prices were much lower than what was predicted back in 2023 due in part to the relative cooling of the geopolitical situation, and milder weather in the first half of 2024.

How Are Our Forecasts Doing Figure 1

Monthly Gas Price Comparison

When looking at a view of the gas prices from OTCGH gas forwards back in the fourth quarter of 2023, we can see that the OTCGH gas forwards definitely indicated much higher prices than what were observed later. Again, our fundamentals-based forecasts provide predictions over a variety of gas scenarios besides the Baseline which is based on the OTCGH gas forwards. We provide a High Gas scenario, as shown in the blue curves, and a Low Gas scenario, shown in the green curves, in order to reflect the distribution of outcomes that can result due to different gas price assumptions. It is visible from the graph that the gas prices in the Low Gas scenario that we used back in Q4 2023 were very close to the observed prices in the first half of 2024.

How Are Our Forecasts Doing Figure 2

Our Forecasts on Different Gas Scenarios

With the gas prices assumed in Q4 2023, we can see across different scenarios that the Q4 2023 Low Gas scenario actually predicts power prices that are quite close to what was observed over the first half of 2024. Of course, it won’t always be clear which of our scenarios will provide the best prediction in each release of our Weather-Smart forecasts. But importantly, our forecasts provide a wide range of market fundamentals scenarios and weather conditions that enable our customers to better understand the risks related to gas prices and renewable build-out assumptions, as well as the range of variability across different weather conditions.

Conclusion

This most recent comparison increased our confidence in REsurety’s Weather-Smart forecasts. The fundamentals and weather scenarios we provide reflect the uncertainties in market fundamentals, and assist our customers in evaluating and managing the risks associated with their assessments of renewable projects. We at REsurety will continue to monitor the state of our Weather-Smart forecasts and keep our customers’ best interests and priorities in mind as we move forward.

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