Constellation Energy said on Friday it would buy privately held Calpine Corp, a geothermal and natgas energy company, in a cash-and-stock deal valued at $26.6 billion including debt, sending Constellation's shares up 3.

Constellation Energy jumped Friday after announcing that it will buy Calpine, adding geothermal and more natural gas to its portfolio.

Constellation Energy’s deal to buy Calpine is being driven by fast-rising demand for electricity by the technology industry.