As temperatures in the U.S. continue to creep upwards due to climate change, so, also, will our dependency on air conditioners. In sweltering summer months, we’ve grown accustomed to strolling indoors to take refuge in a reasonable 72 degrees. But bridging the discrepancy between our personal comfort and the scorching temperatures outside is overtaxing our electrical grid, and meeting the extra demand for air conditioning might require investments of many billions of dollars.
A new study, published in Proceedings of the National Academy of Sciences looks at the relationship between air temperature and electricity use in different regions, then factors in the impact of projected changes due to global warming. Under various projections for how climate change will play out over the century, the study forecasts a 152% to 395% increase in the number of days when the grid reaches the 95th percentile of capacity (that is, nears breaking point). If we manage to reign in global warming through curbing emissions, the researchers still estimate having to add 7% capacity at a cost of $70 billion; if current climate trends continue unchecked and temperatures rise dramatically, that additional capacity requirement would rise to 18%–around $180 billion at today’s prices.
Electric grids are necessarily built to accommodate fluctuation: They need to meet demand in the hottest hours of the year, as well as when air conditioners aren’t so necessary. Warmer parts of the U.S., like the south and the west, already require more electricity to cool buildings; the study says that trend will only increase as overall temperatures rise.
“Our model shows average electricity use increasing, particularly where the grid is already stressed, particularly in some parts of the country, like the south,” Catherine Hausman, an assistant professor at the University of Michigan, tells Co.Exist in an interview. Hausman co-authored the study along with Maximilian Auffhammer at the University of California, Berkeley, and Patrick Baylis, at the University of British Columbia.
There are several potential ways to meet the additional demand without building big plants, the researchers note. One strategy is encouraging people to buy rooftop solar panels–which helpfully produce the most power when temperatures are hottest and demand is highest. Alternatively, “demand response” initiatives encourage people to use less power during peak times by offering financial incentives or pegging electricity costs to demand. The third option is storing more power on the grid for when it’s needed, but the development of grid-scale power storage is severely lacking. Solar panels are not a cut-and-dry solution, either: California has the most rooftop solar in the country, but it hasn’t yet made an appreciable difference in its peak-load needs, Hausman says.
The study shows that, for the time being, it’s probably more cost-effective to focus on reducing carbon emissions and slowing temperature increases than building out the grid to meet expected temperature and demand increases. But, to be certain of that, we’d need to put a price on carbon dioxide through a carbon tax–which lawmakers have been reluctant to embrace. Without tacking a price on our emissions, the future cost of climate change will remain theoretical–even if electricity price increases could be very real down the line.