This paper describes a general modeling approach for optimal planning of energy systems subject to carbon and land footprint constraints. The methodology makes use of the source-sink framework derived from the analogies with resource conservation networks used in process integration. Two variants of the modeling approach are developed for some of the important technologies for carbon emissions abatement: liquid biofuels in transportation, and carbon dioxide capture and storage in power generation. Despite the positive impact on environment, widespread use of these technologies has certain disadvantages. In case of biofuels, their production may strain agricultural resources, that are needed also for satisfying food demands. At the same time, carbon capture and storage is rather expensive technology and its practical implementation in power facilities must be carefully considered and planned. Optimum utilization of both technologies is identified with flexible and expandable mathematical modeling framework. Case studies are used to illustrate the variants of the methodology. (C) 2010 Elsevier Ltd. All rights reserved.