How are Shelter in Place orders Impacting Load and Day Ahead Price Across the Country?

by Sarah Hatch on Apr 15, 2020

Background: Our Yes Energy analyst, Cassie Finer, set out to answer this question using data collected through the DataSignals API. She then used Jupyter Lab with Python/Seaborn to aggregate and chart the data. To compare pre and post Covid-19 impacts, she used two sets of dates for the average hourly Real-time Load and Day Ahead LMP. The pre-Covid-19 data used was from March 1 - April 10 from 2017 - 2020. The post-Covid data includes data from the shelter in place date for the selected city through April 10, 2020. The focus was on Day Ahead price instead of Real-time price because it removed the noise that outages and constraints might create in real-time.

Overview of findings: Across all but one ISO the findings were similar. The shelter in place orders resulted in a lower average hourly Real-time Load and lower, less variable Day Ahead LMP. Below are slideshows of the results of key cities in each ISO. For each city the first chart shows the pre and post-Covid Real-time Load followed by a chart that shows the Day Ahead LMP data. The blue line is the pre-Covid 19 (pre shelter in place) and orange is the post-Covid 19 (post shelter in place). The shaded regions represent the 95% confidence interval. The chart below each shows the percentage difference between the pre and post-Covid 19 data.

ERCOT: RT Load & Day Ahead LMP - Pre & Post shelter in place Comparison

ERCOT Overview:

Houston and Midland have statistically significantly higher load post shelter in place orders.
Houston experienced a warmer than usual March, which could have led to the load increase “washing out” any shelter in place related load decrease.
In all three cities (Houston, Midland & Dallas) the post shelter in place data show a later and steeper load peak than the pre shelter in place data.
Day Ahead LMP is only statistically different in the early hours (spots where 95% confidence intervals don’t cross), with Hour 0 - Hour 10 showing lower predicted prices than pre shelter in place.

PJMISO: RT Load & Day Ahead LMP - Pre & Post shelter in place Comparison

PJMISO Overview:

Real-time Load and Day Ahead price is statistically significantly lower in all three cities (Chicago, Philadelphia & Washington D.C.).
Real-time Load curves look flatter and morning/afternoon peaks are happening a little later in the post shelter in place data.
Day Ahead Price is also flatter with peaks appearing later in the day in the post shelter in place data.

MISO: RT Load & Day Ahead LMP - Pre & Post shelter in place Comparison

MISO Overview:

Real-time Load and Day Ahead price is statistically significantly lower in all of the cities with the exception of Baton Rouge. These cities (except Baton Rouge) also show flatter Real-time Load curves and Day Ahead LMP
In Baton Rouge the post shelter in place data is showing lower load in the morning, higher load in the evening. They have also had warmer than average temperatures in Baton Rouge.

NEISO: RT Load & Day Ahead LMP - Pre & Post shelter in place Comparison

NEISO Overview:

Both cities are showing later and flatter Real-time Load ramps in the post shelter in place data.
Day Ahead LMP is much flatter and statistically lower as well.

NYISO: RT Load & Day Ahead LMP - Pre & Post shelter in place Comparison

NYISO Overview:

Both cities are showing later and flatter Real-time Load ramps in the post shelter in place data.
Day Ahead LMP is much flatter and statistically lower as well.

CAISO: RT Load & Day Ahead LMP - Pre & Post shelter in place Comparison

CAISO Overview:

Los Angeles post shelter in place Real-time Load is lower and flatter while San Francisco post shelter in place still has a steep (but significantly lower) load curve.
In both cities the shapes of the curves are similar in pre and post shelter in place data.
In post shelter in place the Day Ahead LMP in San Francisco is much flatter. Prices are lower in the morning and evening and a bit higher mid-day.

SPP: RT Load & Day Ahead LMP - Pre & Post shelter in place Comparison

SPP is somewhat unique, Tulsa and Omaha don’t have shelter in place orders but we are still seeing statistically lower Real-time loads in both of those cities and lower Day Ahead LMPs.