Establishes the name of the act as the North Carolina Energy Market Expansion Act.

Amends GS 105-129.16D to provide for a tax credit for any taxpayer that (1) purchases/constructs, (2) installs, and (3) places in service a qualified commercial facility for distributing, dispensing, or storing alternative fuel. Provides credit will be in the amount of 25% of the cost of purchasing or constructing and installing the facility. Sets out what can be included in such costs and counted toward the calculating of the credit. Deletes subsections (b) and (b1), regarding certain tax credits for renewable fuels. Makes conforming changes. Changes the sunset date for this section to January 1, 2025 (was, January 1, 2014). Effective for taxable years beginning on or after January 1, 2015. 

Amends GS 105-129.15 to add and define the key term alternative fuel. Effective for taxable years beginning on or after January 1, 2015.

Enacts new GS 105-129.16K, which creates a tax credit for placing into service certain vehicles that are propelled by alternative fuel. Sets tax credit at 50% of the incremental or conversion costs for placing such vehicles into service. Sets out and defines terms for the section, including alternative fuel vehicle, conversion cost, incremental cost, and qualifying vehicle. Establishes ceilings for the tax credit. Provides that the section sunsets on or after January 1, 2025. 

Amends GS 105-130.5B, adding a new subsection (h) that establishes a special rule for alternative fuel vehicles in regards to the states decoupling from federal accelerated depreciation tax provisions. 

Amends GS 20-118(c) to establish a weight limit exception for the operation of vehicles that are wholly or partially fueled by natural gas. Provides that such a vehicle can be operated on highways of the State at a weight no more than 2,000 pounds above the otherwise applicable weight limit. Provides limitations of the exception.