Solar Down Ramp Drives After Dusk Price Spikes in ERCOT

Although growing solar production can shift the summer net load peak and scarcity pricing to the post-sundown hours in ERCOT, our Live Power analysis shows this dynamic impacting non-summer scarcity pricing as well. In this white paper, we’ll take a closer look at key price drivers, revealing the notable impact of growing solar supply and the shifting thermal supply stack. 

Our October analysis of ERCOT highlights the impacts of growing solar in the overall changes to net load shape. As the net load shape transformed, a shifting thermal supply resulted in greater peaker participation, increased market heat rates, and price variability. 

Although October average net loads and prices were similar in 2021 and 2022, market-implied heat rate expanded 10%. Important to note is that net load ramps get steeper as more solar comes online. As the sun sets, solar production declines quickly; the more solar online, the greater the net load ramp can become. Live Power data reveals a shift in supply stack - and greater peaker participation during evening peak hours.  

As more solar comes online in ERCOT, it is reasonable to expect greater net load impacts in the pre-sunup and post-sundown periods - particularly in months with low loads such as October.  Data from Yes Energy and Live Power are key to breaking down the moving pieces and gaining greater insight into market price formation.