Shares of power producers fell as long-term Treasury yields closed at multiyear highs.

The 19-year highs in the 30-year yield present an attractive alternative to dividend yields for fixed-income investors. The relatively high debt levels of utilities also make rising Treasury yields a headwind.

One strategist said those factors could be offset by the historic increase in electricity demand triggered by data-center development. "Last year, utilities were the second weakest sector after consumer discretionary...that just seems illogical to me," said J.D. Joyce, president of Houston financial advisory Joyce Wealth Management. Even if only a fraction of the sometimes speculative data-center proposals come to fruition, electricity consumption is bound to increase dramatically, Joyce said. "It's only a matter of time but the demand is there."