The development, implementation and monitoring of the Sustainable Energy and Climate Action Plan require a significant amount of data and analysis, as well as an effective and comprehensive decision making process. This chapter presents the pilot application of the proposed “MPC+ (Map - Plan - Choose - Check)” framework, through the “Action3” Decision Support System, in a Greek energy-producing community. The pilot application is conducted in three phases, namely the development of the baseline emission inventory (Phase I), the creation and evaluation of alternative Scenarios of Actions (Phase II) and the monitoring of the actions and measures implemented (Phase III). The city's univocal economy orientation of energy production through lignite is considered as a basic, inhibitory factor towards sustainability. In this respect, the city has committed to implement a series of appropriate renewable energy and rational use of energy activities in its territory, laying balanced emphasis on the local energy and heat production, and the promotion and implementation of measures on energy savings. A significant part of the CO2 emissions' reduction will come from the installation of biomass district heating systems in local communities.