For the last two decades, homeowners have been able to claim thousands of dollars in federal tax credits to help offset the high up-front costs of going solar. They are basically saying they aren’t going to help people with rising energy costs.”The country’s first solar tax credits took effect in 1978, but were allowed to lapse in 1985, when President Ronald Regan was in office. That means a tax credit would be worth around $8,500. The so-called 25D tax credit would still apply for systems that are installed this year, and then it would go away completely. Without the tax credits, solar systems might still make financial sense in places that get a lot of sun or have high electricity prices, or both, but the payback period will likely grow.