Energy credit reduced – For 2011, the lifetime maximum for the energy property credit is reduced from $1,500 to $500. Taxpayers who never claimed the credit can claim the entire $500. But, those who claimed $500 or more for the 2009-2010 and/or the 2006-2007 energy credits are not eligible in 2011. Eligible improvements include external windows and doors, insulation, roofing, HVAC and non-solar water heaters meeting specific energy guidelines.