Grid Status

CAISO's Extended Day-Ahead Market (EDAM) got another new participant today. The data is flowing into Grid Status, and here’s what we’re watching. Portland General Electric (PGE) is the third balancing authority to join EDAM, a voluntary day-ahead market that builds on the Western Energy Imbalance Market (WEIM). PGE’s entry adds to EDAM’s growing footprint ahead of SPP’s alternative day-ahead market, Markets+, launching next year. You can now explore PGE’s day-ahead prices, load, and wind forecasts on our EDAM Live Page alongside the rest of our California ISO data. Tracking price movements will help reveal the strengths and shortcomings of these market designs as the Western Interconnect landscape shifts. Beyond prices, PGE’s battery activity is worth watching: discharge can exceed 400 MW during the evening peak, equivalent to about 10% of evening load. That makes PGE an interesting region to follow as storage expansion shapes prices and market dynamics across the grid. Our team of market analysts will continue sharing anything interesting we see on Grid Status Insights.

Our very own Connor Waldoch was on CAISO's podcast to go over early EDAM results (with charts of course). Check it out wherever you get your podcasts, or on YouTube for the visual element. If you want to track EDAM results in real time, check out the tab on our CAISO Live Page and be on the lookout for additional updates when Portland General Electric joins on October 1st.

Yesterday, we touched on the rise of congestion costs in Dominion. One of the clear drivers for this upside is continued data center buildout in the zone. Off-peak load levels in May continued to rise year over year, with early morning load, HE1 through HE6, rising 1 GW year over year. The early morning off-peak offers a strong opportunity to look at load trends, as during mild weather, it is primarily made up of baseload demand and increasingly data center load. While not all of the increase can be attributed to data centers, as native load growth played a factor, new large loads make up the majority of this 1 GW increase. This increase is in line with expectations, as Dominion expected to see an increase in data center load following a series of transmission upgrades. With this week’s heat, Dominion may hit a new summer demand peak, beating a record set earlier this month. Until load itself approaches major stress thresholds, expect system-wide fireworks around the net load peak as the market rapidly moves up the bid stack each evening and congestion manifests in the usual hotspots. Track all of this and more with our Live pages, Forecast Analysis app, and running commentary in Grid Status Insights.

Forecasted heat and humidity at the start of July are expected to further widen lopsided Dominion congestion costs this year. Year to date, average real-time congestion costs for the Dominion load zone are tracking well above every year since 2018 for the same timeframe. Congestion costs in the morning were heavily skewed by extreme cold temperatures in January, particularly during Winter Storm Fern, but even this upside has paled in comparison to the volatility seen over the afternoon and evening as the weather has warmed. Recent weeks have seen the Dominion zone subjected to rounds of volatility by constraints located in or near the heart of data center alley, like Ox XFMR, Ashburn-Goose Creek, Morrisville-Loudoun, and Bedington XFMR, resulting in disproportionate levels of upside. With feels-like temperatures forecast to push well over 100 degrees for days on end this week, expectations are for these conditions to continue. Be sure to track an early round of fireworks ahead of the 4th with our PJM live page, as well as curated analyst commentary on our Insights feed during the heat wave. 

The loss of California's battery crown has been greatly exaggerated, if you measure actual unit capability. The EIA's operating plant inventory reports not just nameplate capacity, but also MWh. Using this value, we see that California's installed grid-battery GWh total is greater than the sum of the next two states, Texas and Arizona. CAISO's 4-hour standard and ERCOT's tendency towards 1 and now 2-hour projects means that comparing MW nameplate alone across states and markets is a fraught endeavor and non-representative of the fleet's total ability to shift power over time. Arizona's fleet looks more like CAISO's with the average duration sitting at 3.7 hours, above California's ~3.4, and more than twice Texas' 1.5. Of the Arizona batteries, about half of the total energy sits within Arizona Public Service Company territory, while a third are with the Salt River Project. This figure also tells some of the story on just how far behind the two largest markets, MISO and PJM, are in terms of battery buildout. Not a single state from either ISO shows up in the top 5. In fact, it's not until Indiana in the 12th position that either market makes an appearance.

Our ERCOT 4CP Monitor application is free for all users during the month of June, and today looks set to challenge the current June 4CP interval. Just this morning, we added a new Daily Peak Window card to the app to provide a more intimate look into a given day's peak window. You can track peak periods in real time with the new card, review the outlook over time with Forecast Evolution figures, and plan for the next seven days with our fully transparent Risk Outlook. The latest forecast for this evening dipped back below 80 GW, but has been increasing with recent forecasts and still exceeds the current peak by ~1.3 GW. Peak curtailment has been strong in recent days, but the risk of a new peak remains. https://lnkd.in/e_aaAmgE

The PJM Interconnection's Dominion zone could break its all-time summer peak record this Friday. The latest Dominion Forecast has the zone peaking at 23,790 MW on Friday, just 46 MW below its previous record summer peak, which occurred last summer during a major East Coast heatwave. Notably, Dominion’s load peak is expected after the RTO as a whole and makes up a larger-than-usual portion of the entire system’s demand, up to 17%. During the zone’s record last year, Dominion comprised 15% of the overall load at the time, indicating that heat and humidity are much more concentrated in Dominion and Eastern PJM on Friday than during last summer’s heat event. The strength of this peak alone is likely to drive strong day-ahead and real-time congestion in Virginia, but a widening demand gradient due to unsettled, cooler weather in the West will strengthen W-E flows and increase the risk of constraints like the AP South interface. Unlike during the 2025 East Coast heatwave, PJM has not yet issued emergency calls for action beyond a Hot Weather Alert. The lack of these calls, as well as the drop in RTO-wide load, could keep pressure on the Dominion load peak itself, as it may limit the risk of load curtailments, though this could change ahead of the event, particularly as the transmission situation evolves. Track nodal prices and congestion with our PJM live page, and monitor changes to the RTO forecast as we get closer to Friday with the Forecast Analysis tool.

We’ve launched a public dashboard for EDAM participants to track outcomes in member balancing authorities and better understand the market. You can find it under the EDAM tab on our CAISO Live Page. With each new market, fundamentals shift, so take a look and reach out if there’s anything else you want to see tracked! The page will keep expanding as new balancing authorities join the market, so look out for updates this autumn when Portland General Electric makes the jump.

Wind generation wasn’t the only record-setting grid event for CAISO in April. Curtailment in both wind and solar spiked to record-shattering levels across the month. For both solar and wind, curtailment peaked in the late afternoon, while overnight hours saw typically low levels of curtailment. This is in stark contrast to the beginning of the year, as January saw quite low curtailment in both resources. Look for more from us on CAISO in the coming weeks; it’s been an interesting spring even beyond market expansion.

Three years ago, MISO lagged PJM in solar capacity. 1 year ago, the markets were neck and neck. This year? MISO has completely pulled away. Since the first half of 2023, PJM's peak solar output has roughly tripled, while MISO's has lapped that growth, increasing more than 6 times over. Strong incentives in a handful of MISO states and well-documented interconnection woes in PJM contributed to the growing disparity. Three years ago, on the same day as MISO's current record (April 20th), solar failed to reach even 3% of the total fuel mix. Now, it can be the largest single source of generation during its peak hours.