Migo-Sumagang M.V., Aviso K.B., Bhasker Nair P.N.S., Short M., Tan R.R., Foo D.C.Y., 2022, A Graphical Technique for Net-zero Emissions Planning Based on Marginal Abatement Cost (MAC) Curves, Chemical Engineering Transactions, 96, 451-456.
Net-zero emission targets are being set by countries and companies globally. To meet net-zero targets, negative emission technologies (NETs) such as bioenergy with carbon capture and storage (BECCS) and biochar (BC) can be implemented alongside replacing traditional energy sources with renewables. Various high-level tools for energy planning are available but rarely consider NETs and net-zero emissions planning. In this work, a graphical procedure was developed using marginal abatement cost (MAC) curves for net-zero emissions planning. Carbon dioxide (CO2)-emitting energy sources are arranged in increasing order of specific costs, on a specific cost vs cumulative CO2 emissions diagram. NETs are then plotted to counterbalance the emissions in order to determine the negative emission targets. The methodology is illustrated with a case study in the power generation sector. In this case, coal and natural gas (500 MW each) are used to generate power for users. In order to reach net-zero emission for this sector, a BECCS plant (500 MW) and a reduction in the power rating of coal by around 200 MW is necessary. Besides, an additional 1.59 Mt/y of CO2 sequestration is to be carried out through BC. The proposed technique provides a simple and clear method for net-zero emissions planning.