In February 2021, Winter Storm Uri hit the state of Texas, impacting all 254 counties. The Federal Energy Regulatory Commission reported more than 4.5 million people lost power, some up to four days. According to the Texas Department of State Health Services, the lack of power during the record-breaking freezing temperatures resulted in 246 deaths. Justin Fields, principal data scientist with Xcel Energy, said this situation is exactly why accurate data collection for energy outputs is vital – to prevent another Great Texas Freeze. NASA Earth observation data from the Prediction of Worldwide Energy Resources (POWER) project helps them achieve that.
“Our service territory from…Minnesota down to Texas was frozen. All of the wind turbines froze up, the solar panels were covered in snow,” said Fields. “This type of data would help us kind of understand and quantify those risks and plan accordingly for that.”
Xcel Energy is an electric utility and natural gas company serving four million electricity customers and more than two million natural gas customers across eight Southwest and Midwest states: Texas, Colorado, Michigan, Minnesota, New Mexico, North Dakota, South Dakota, and Wisconsin. Xcel Energy said its electric grid is connected to 1,160 active solar gardens, primarily in Minnesota, Colorado, and Wisconsin. These solar gardens transmit a total of 1,168 megawatts of alternating current energy. Xcel Energy cited industry averages that say one megawatt of solar can power about 139-153 homes in northern states.
Instead of people needing to install their own solar panels on the roofs of their homes, Xcel Energy’s customers in Minnesota and Colorado can join its Solar*Rewards Community – the nation’s largest community solar program. In Wisconsin, customers can join the Solar*Connect Community. These programs allow customers to subscribe to a community solar garden (CSG) in their area. Xcel Energy will then give customers credits towards their monthly utility bill for the solar energy their subscription contributes to the electric grid, allowing people to save money, and getting Xcel Energy closer to its net-zero emissions energy plan. In Minnesota, for example, Xcel Energy customers save about 10% annually on their electricity bill according to Join Solar, a community solar provider and Xcel Energy partner.
To manage and plan for the CSG's energy loads, Xcel Energy’s Model Innovation and Strategy team monitor their power generation with in-situ sensors. However, there are times when the sensors fail, or give “bad reads.” In the summer of 2024, the team came across NASA POWER and began using POWER data to fill in gaps of information for 360 of Xcel Energy’s CSG locations. The team accessed POWER data through NASA managed Amazon Web Services Open Data Registry. The team said POWER’s cloud-optimized data format, Zarr, was easily accessed via a cloud-based data intelligence platform. They observe solar irradiance, temperature, cloud coverage, and precipitation parameters to monitor the CSGs’ performance.
Read about NASA POWER’s collaboration with Zarr to store and serve data.
An example of the performance monitoring of a specific solar garden is shown in the two graphs below, which were both generated from Xcel Energy’s data cleaning tool, which allows them to identify and visualize inconsistencies in the data from in-situ sensors placed at CSGs. The data cleaning tool predicts the missing or potentially faulty data by pulling in POWER data. In both graphs, the gray represents the raw hourly data collected from the in-situ sensor, which cuts off in between January and July of 2022. The second graph shows where POWER’s data comes in, picking up in 2022 and continuing through the beginning of 2025. POWER data also fills in gaps between 2021-2022 that the in-situ sensor missed.
NASA POWER provides accurate and reliable, near real-time, global data that companies like Xcel Energy can count on. Fields said one of the interesting conclusions his team was able to understand more from analyzing POWER data is that typically, especially in southern states, utility companies plan for “summer peaks” – high demands on energy due to air conditioning use. However, snow and ice storms, like Winter Storm Uri, are an example of how the wintertime is one of the hardest times to meet load.
POWER data gives Xcel Energy the information it needs to plan for ways to supplement energy during load peaks. Planning allows utility companies to optimize resources and funds ahead of time, minimizing costs that occur in reaction to an energy crisis while remaining reliable. Reliable energy saves lives, ensuring people do not go days without heat during freezing temperatures or air conditioning during a heat wave.
“We are focused on working through the energy transition while being reliable as possible,” said Fields.
Xcel Energy hopes to expand its collaboration with the NASA POWER project on several future projects, such as for its rooftop solar panel development project. The company is also discussing plans to use POWER data in a risk analysis to inform resilient energy decisions 10-30 years in the future.
“For example, if we think that the wind pattern is going to change 10 years from now, it’s not worth it to build power generation near that [area],” said Mahdi Salavatian, principal data scientist with Xcel Energy.
NASA POWER’s global, reliable, and easily accessible data helps companies like Xcel Energy make those tailored decisions for the customers it serves.