It is critical to limit global warming to 1.5 degrees C by the year 2100 to minimize catastrophic impacts. The increased integration of renewable energy, alongside CO2 capture and storage (CCS) deployment in energy planning, remains as a key mitigation technique in minimizing climate change impacts. Although renewable energy generation approaches the ideal of a carbon-neutral system, other processes such as fossil fuel-based generation, manufacturing, and transportation are net-carbon positive. Additionally, renewable energy poses challenges such as its sensitivity to environmental conditions, geographical location, and seasonal changes. On the other hand, CCS entails a high capital expenditure, as well as additional operating costs due to parasitic power loss. Therefore, the deployment of negative emission technologies (NETs) as a carbon management option is imperative. The generation of electricity from power plants with the installation of NETs can offset positive emissions from elsewhere in a system. This paper presents an extended graphical technique for the incorporation of NETs during energy planning. The graphical technique that was originally developed for the planning of CCS deployment in power plants is now extended to determine the minimum NET requirement during energy planning. Three examples are solved to illustrate the methodology of the extended graphical technique in determining the minimum NET requirement during energy planning.