This latest Polar Vortex to hit the Northern Hemisphere was truly an extreme weather event. The Natural Resources Defense Council (NRDC) is reporting that it was so cold “that bananas could be used as hammers and tossed boiling water froze before hitting the ground.”
When it is this cold, the one thing that concerns everyone is having heat, and this was an excellent opportunity to get a first-hand look at how the nation’s power grid would stand up to the extreme weather event. Energy consulting firm Wood Mackenzie used the opportunity of this event as a chance to measure demand on the power grid.
The study, titled, “Performance review: nuclear, fossil fuels, and renewables during the 2019 Polar Vortex,” took a look at how various forms of energy performed, including projections of how resources would fare in a 100 percent renewable energy scenario.
Conclusions reached
In an interesting conclusion, Wood Mackenzie said that even if wind and solar were scaled up to produce as much power as the electrical grid supplies now, many people would have been left without power for several hours each day without additional energy storage capacity.
“Any mix of wind and solar to serve load would require long-duration storage or optimization of multiple ‘stages’ of shorter duration,” the study concluded. Woods Mackenzie further notes that this situation was further aggravated by a lack of adequate transmission to exchange power between various grid operators, and even within grids.
This was demonstrated on two particularly cold days – January 30 and 31 -1n the Mid-continent System Operator (MISO) and Southwest Power Pool (SPP) grids. There isn’t much solar yet on these grids. And while wind power was doing its part, this left coal, gas and nuclear power to do the heavy lifting.
The study notes that “limited transmission capacity meant that MISO South power prices remained low”, and that as the cold let up in SPP it was unable to provide support to MISO and PJM due to transmission limitations.
It all comes down to storage
Storage of between 18 and 40 hours would have been enough to bridge the gaps in the first polar vortex of 2019, the study concluded, as long as there were no gaps in transmission. We know that wind and solar are intermittent, with solar being at its best during daylight hours.
So while solar was able to come online and cover daytime peak loads, combined, solar and wind were not enough to cover peak loads during the evening as the sun began to set and after. This situation left large gaps during the coldest nights that could have been covered with adequate battery storage.
The study also said this year’s Polar Vortex was not as severe or as long-lasting as the one that hit the U.S. in 2014. Utilities drew 17 percent more natural gas per week then to meet demand than they did this year. Based on this year’s Polar Vortex, the renewable grid would need up to 40 hours worth of energy storage to make it through the worst of the cold weather. In a more widespread and longer chill it would need even more storage.
Projections for a 100 percent renewable future
It should be noted that while solar and wind power sources worked during the whole of the extreme weather event, the vortex did cause the shutdown of a nuclear reactor in New Jersey and drove many coal plants offline in the Mid-Atlantic and Midwest. The weather event also contributed to a fire at a natural gas compression station in Michigan, limiting LNG supplies during a peak period of need.
As the Wood Mackenzie report points out, no one power source is foolproof, and this includes coal. It is the grid managers that are the important key to balancing our electrical supply, ensuring that when we turn on the light switch or need heat that the power will be there.
The keystone to having a successful and reliable electric grid is having energy sources that aren’t prone to failure, and solar and wind resources have very few failures. Grid managers have deep experience successfully integrating their electricity into the power grid.
If the U.S. is to hit a target of 100 percent renewable energy – we would need a significant amount of storage capacity – as well as more transmission lines and renewable generation capacity. This is not taking electric vehicles into account. If we add in EVs, we will need even more storage capacity.
