Qualifying vehicles include pure electric and plug-in hybrid vehicles as well as vehicles that run on compressed natural gas or liquefied petroleum gas. As long as these vehicles have a gross vehicle weight rating (GVWR) of 9,600 pounds (CNG and LPG) or 8,500 lbs (EVs and PHEVs) or less, they qualify for the $2,500 rebate. The plug-in vehicles need to have a battery that is at least four kWh. ChargedEVs says that the rebate program expires August 31, 2015 and has enough funds for 2,000 vehicles EVs and 2,000 CNG vehicles a year.
Texas has a history of supporting EVs, with a strong charging infrastructure in place and growing Nissan Leaf sales. Some residents can also qualify for Texas' "Drive a Clean Machine" program. It provides $3,500 for people who live in certain counties and have a net income under set limits. Details here.