A utility company locked thousands of customers out of their smart thermostats in Colorado

Photo by PATRICK T. FALLON/AFP via Getty Images

Thousands of Colorado residents were locked out of their smart thermostats last week in order to prevent power demand from overwhelming the grid.

According to Denver7 News, about 22,000 Xcel customers lost control of their smart thermostat. Some people said the temperature in their homes was as high as 88 degrees. Much of the western US was in the middle of a heat wave that reached into the 90s.

The AC rewards program was put in place to ease the strain on the power grid during the hot summer months. When demand is so high that there isn't enough supply to meet it, the company can adjust the thermostat. After signing up, Xcel will give you a $100 credit on your electricity bill.

The customer has the option to opt out when the thermostat is adjusted. On rare occasions, system emergencies may cause a control event that can't be overcome.

In the six years since the program started, last week was the first time that customers were barred from over adjusting. Last week's energy emergency was caused by high temperatures, soaring power demand for air conditioners, and an unexpected power failure. The company did not respond to a question from the website.

The Western US is in the middle of a heat wave that is expected to last well into this week. Californians have been urged to conserve energy over the next few days in order to avoid the possibility of a power failure.

More extreme weather has led to more power interruptions for Americans. It was a record year for power failures. Punishing summer heat in Texas last year led to backlash from residents when utilities set smart thermostats to higher temperatures.

Demand response is a strategy that is supposed to help power grids become more resistant to extreme weather events as global temperatures rise. There is a precarious balance between supply and demand that can lead to power shortages. When there is a spike in demand for electricity, demand response can smooth it out. If some customers see their thermostats set to higher temperatures than they anticipated, that will help keep power on for them and their neighbors.

If homes are kept at high temperatures, there is risk with that strategy. Exposure to high temperatures at night can cause heat-related illness and even death. More people die from heat spells in the US than any other weather disaster.