If you made energy efficiency improvements to your home in 2014, you may be eligible for a substantial tax credit. Here are the six areas for which tax credits have been made available:

• Biomass stoves (this would mainly be wood or wood pellets, though there are some other, less common kinds)
• Upgrading to a more efficient heating or cooling device (a more efficient boiler, a heat pump, etc.)
• Insulation
• Improving efficiency of your roof
• Non-solar water heater
• Sealing/improving windows and doors

Full information is available on the Energy Star site, here.