Fracking technology that led to a surge in US oil and gas production is now working its way into the geothermal industry, lifting returns for the nation’s biggest holder of leases for wells that tap the Earth’s heat. Fervo Energy Co., a Houston startup with $1 billion backing from venture capital and energy companies, plans to raise more money to fund innovations that it says dramatically improve the economics of geothermal wells. The technology holds the promise of delivering a steady flow of emissions-free electricity, making it attractive to fuel the power needs of data centers that operate around the clock and in all weather. Tim Latimer, Fervo’s co-founder and chief executive officer, spoke in an interview at the BloombergNEF Summit in Houston.