(Bloomberg) — The big red billboard planted by a solar company alongside a Southern California freeway warns passersby that the “Solar Tax Credit Is Expiring,” beckoning homeowners to install solar panels and batteries before the Trump administration eliminates the generous incentive on Jan. 1. The deadline has helped drive a big spike in business for solar installers as buyers rush to qualify for the 30% tax credit before it disappears. But California installers said lengthy utility permitting times coul ...