Who Will Swelter This Summer? The Pressures on the Nation’s Power Grid

When it comes to keeping the lights and air conditioning on this summer, how much of a safety margin do we need?

After all, summertime is when electricity demand surges, as an entire nation reaches for the thermostat in the midst of a heat wave. Overall, our grid is getting older, and the demands are getting higher.

The North American Electric Reliability Corporation, the agency that’s paid to worry about the power grid in the United States and Canada, says we’re reasonably good shape for the summer—except for Texas and maybe California. Of course, given how large Texas and California are, a worst case scenario could leave some 60 million Americans sweltering in the summer heat.

As you’ll see on this map, most regions of the country have enough capacity in reserve. The percentage on the left is the actual reserve available, while the percentage on the right is the “reserve margin” that NERC says should be enough to get by. Most parts of the country are doing pretty well — in fact some, like the Gulf and Central regions, have two or three times the reserve they need.

Only one part of the country is actually below the reserve margin: Texas. Demand in Texas is outstripping supply (demand has increased by 2.3 percent in 2012-13, but supply has only increased 1.4 percent, according to the Energy Information Administration). Texas utilities may bring mothballed generating stations back into service and use more aggressive “demand response” programs aimed to manage increased demand during peak periods.

It’s important to note that this doesn’t mean there will be blackouts this year – only that Texas has less of a safety margin than it should have if things go wrong.

California has enough reserve on paper, but may be cutting it close in reality because two units of the San Onofre Nuclear Generating Station are off-line and due to be retired. California officials have put a number of steps in place to bolster service.

NERC says two other factors may have a big impact on whether the lights stay on this summer, and they’re both, well, elemental: wind and water.

Water will be an issue because of expected drought in the Western states this summer. That matters to power plants because many conventional generating stations draw cooling water from rivers and other bodies of water. If water levels drop, the plants may not get the water they need, or may exceed environmental restrictions on how much they can use. That isn’t a certainty, but NERC warns that utilities will need to watch out for it.

Wind is an issue, ironically, because wind power is becoming more and more popular. In fact, government studies have shown that wind farms and natural gas account for almost all the new generating capacity in the United States over the past decade. As a carbon-free, renewable power source, wind has huge benefits.

But it also has a significant drawback, which is that the power you get from wind farms fluctuates widely depending on the weather. That means that you can’t automatically count on wind farms to be producing wind power just because electricity demand is peaking—it’s either a windy day or it’s not. This also means that grid operators need to adjust to significant changes in wind energy output. That is doable — European countries that rely more on wind are learning to deal with this. But we need a more modern grid to do it here.

Overall, the U.S. power grid is both huge and aging. There are a whole host of energy options that will never get off the ground without a better grid: electric cars, expanding wind and solar, and, as the latest reports show, just keeping up with demand.

Modernizing the grid will take money, and and it isn’t something we can do while we’re focused on the short term. Without a better grid, we may get through this summer, but we’ll still have to worrying about the summers to come.