As winter deepens and February approaches its second half, the SPP grid is taking on a new shape, reflecting notable shifts in the supply and demand dynamics. While solar continues to inch higher, the most striking change has been the resurgence of coal-fired generation. Faced with cooler temperatures (year-on-year) and heightened demand, we will discuss how the grid has been impacted.

Starting with an overview of the SPP market, the graph below displays a 12-month by 24-hour profile of the supply and demand components. From top to bottom, the panes show demand, wind generation, net load, solar generation, thermal generation (natural gas and coal), and day-ahead heat rate values. Load has been higher this winter, particularly in February (with data available for only 12 days so far). With wind generation coming in lower compared to the past two years, net load has been stronger this month. The thermal generation profile has shifted significantly, particularly this February, with coal generation nearly doubling compared to last year. From a heat rate perspective, day-ahead heat rates have been trending lower year-over-year in the north this February, while hovering close to the levels seen in the past two years in the south.

Figure 1 | SPP 12x24 Profile