Half of electric-utility executives surveyed recently expect their industry to go into a “death spiral” within 10 years, a trade journal reports. Those executives manage companies with big capital-spending programs, high dividend-payout ratios, and scant prospects of raising their sales volumes.

Don’t blame the Great Recession. Electricity sales have barely increased in the seven-year upturn after the economy hit bottom. And don’t blame competition from rooftop solar collectors. The decoupling of electric sales and economic...