The costs and challenges of expanding Plant Vogtle continue to grow, in part because the number of workers diagnosed with COVID-19 is on the rise, Southern Company acknowledged Thursday.

The Atlanta-based company, which is the parent of Georgia Power, forecasts it will cost $149 million more for its share of the project. It said Georgia Power could eventually ask state regulators to charge customers for the increase.

Southern also reported on Thursday quarterly declines in its latest revenue and profits, compared to a year ago, as overall electricity use fell with the pandemic and the battered economy. Commercial and industrial customers used far less electricity. But residential electricity use rose 5% as people spent more time at home.

Southern said the pandemic continues to affect work at Vogtle, which was already billions of dollars over its original budget and years behind schedule.

In April, the company cut 2,000 jobs on the project after absenteeism rose and coronavirus cases grew at the massive construction site south of Augusta. Southern said the number of cases among workers declined significantly, but began to increase again in mid-June and “continue to impact productivity levels and pace of activity completion.”

Still, the company said it expects to have the two new nuclear units operating by November 2021 and November 2022.

Georgia Public Service Commission staffers and independent monitors have testified that, even before factoring in the pandemic’s impact, it is “highly unlikely” that Vogtle will be completed by then. And they predicted the project will be $1 billion over its current budget.