The deep freeze on Christmas weekend exposed major flaws in their approach:
The first domino fell in Duke Energy Carolinas territory, which serves 2.5 million residential, commercial and industrial customers. Starting at midnight on Christmas Eve, utility officials cut back power at the Dan River combined cycle plant, which runs largely on natural gas, to 360 MW, roughly half of its capacity, said Sam Holeman, vice president of transmission. (This is also known as derating.) Some of the plant’s instrumentation had frozen, and to prevent the facility from failing altogether, operators had to reduce the strain. The Buck plant in Salisbury encountered low pressure issues and had to be derated after peak energy usage had passed.
Solar energy “performed as expected,” Duke officials said, although it was not available overnight during the peak hours of 2 to 6 a.m.
It could have been available to ease that burden if Duke had dedicated more resources to battery storage in NC:
In the city of Asheville, a 9-megawatt (MW) lithium-ion Samsung battery system is operating next to a Duke Energy substation in the Shiloh community. With a total cost of less than $15 million, the project will primarily be used to help the electric system operate more efficiently. It will provide energy support to the electric system, including frequency regulation and other grid support services.
Battery storage offers many benefits to customers. Duke Energy has plans to invest $600 million for 375 MW of energy storage across its regulated businesses.
“Energy storage will play a significant role in how we deliver energy to customers now and into the future as we act to reduce carbon emissions by at least 50% by 2030 and achieve net-zero carbon emissions by 2050,” said Stephen De May, Duke Energy’s North Carolina president.
Duke Energy has more than a decade of experience with battery storage. At one time, the company’s 36-MW battery system next to the company’s Notrees Wind Facility in Texas was the largest battery operating in the United States. It remains one of the country’s biggest.
Get that? NC gets a measly 9 megawatts battery storage (largest in the state) in 2020, but that 36 megawatt system in Texas came online in 2013. In other words, they've had the technology and the resources available to boost NC's storage capacity, but have mostly demurred. Keep in mind, our state is the 3rd largest producer of Solar electricity in the country. More batteries here is a no-brainer, and yet Duke is spending hundreds of millions building batteries in the 9th-ranked solar state (Florida):
By the end of 2022, Duke Energy says the six projects in Florida will have a combined 50MW power. The other three are in Jennings (5.5MW/5.5MWh), Micanopy (8.25MW/11.7MWh), and a 1.5MW/2.5MW solar-plus-storage microgrid at a school in Pinellas County. The company has previously said that installing storage is an economic alternative to building out its distribution grid.
Florida has been slower than other states like California and Texas when it comes to adding energy to its grid. But it did recently unveil the largest BESS to be be paired with solar PV late last year.
While more battery storage here in NC is part of Duke's Carbon Plan, it's a small part. Much smaller than it should be, considering the 6+ Gigawatts we are currently producing.