Kiplinger's reports that the 2015 residential energy credit will be available again in 2016. It works like this. You can write off 10% of your purchase of energy efficient doors, windows and insulation (up to $500). The credit only works for residential (nonbusiness) property. Credits taken in prior years count against the $500. This is not the case for the 30% solar energy system credit, which applies through 2019 and phases out in 2021.
This is a great time of year to lock in the heat and the tax savings. You have to buy and install by December 31, 2016. So, get a move on!