U.S. Looks to Tap 1950s Law to Boost Clean Technology

The solar industry, heat pump makers and electric-vehicle battery manufacturers are among those expecting benefits from the recently passed climate bill that will allow the government to make grants and purchase orders under the Defense Production Act.

The caveat: No one is quite certain how it will work.

“I am optimistic, but it’s still unclear to me what they will do,” said David Calabrese, senior vice president of government affairs for the U.S. subsidiary of Japanese Daikin Industries Ltd., which makes electric heat pumps at a factory outside of Houston.

The 1950s-era Defense Production...