The heat will strain the grid today and tomorrow

Whether the lights stay on today and tomorrow will hinge on a few main variables: how high is demand, how much power can we import from PJM (the power grid to the east of us), and how hard will the wind be blowing?

Demand will be determined by the heat and people’s desire to flip on the air conditioning. Import availability will depend on how widespread the heatwave is. If demand is high in PJM, as well as in the Midcontinent Independent Systems Operator (MISO), the electric grid to which Minnesota belongs, then PJM will have fewer electrons to send our way.

The final factor will be wind generation. At the moment, MISO’s day-ahead prediction of wind generation looks like it will be sufficiently windy to meet demand.

MISO usually assumes wind generation will be operating at 15.5 percent of its potential output when the electricity is needed most. This means MISO expects at least 4,143 MW of wind on the system, which we should easily clear going into tomorrow.

While the lights will likely stay on this week, it’s important to remember that hoping for windy weather, instead of having enough reliable power plants on the grid to meet demand, amounts to gambling on the reliability of the electric grid. Sometimes it will work out, other times it won’t.