The project "E²SOL – Energy-efficient City Oldenburg" is the contribution of the city Oldenburg in the competition of the "Federal Ministry of Education and Research" called "Energy-efficient City". This research-project sets a milestone to mobilize the city of Oldenburg as "City of Science 2009" sustainably and to lead to further research-initiatives. Among fifteen other cities, this contribution has been chosen for the twelve months sponsored concept-phase, 72 cities competed for. For the following project phase three to five of these cities will be selected for a further three to five years sponsoring. The cooperation partners of the city of Oldenburg along with OFFIS are EWE, RIS Energie, the Max-Planck-Institut for Plasmaphysik and the University of Oldenburg.

During the concept-phase, which is running since 01.04.2009, an energy-model for the city of oldenburg will be created with the software "TIMES". Furthermore accounting-, simulation- and optimization-tools will be developed and tested. In the prospective project-phase the tools will be used for energy- and emission-accounting in the sectors mobility, habitation, working, and services. To increase the energy efficiency and to decrease CO2-emissions a new concept of energy consumption will be designed: The main idea is to involve the citizens in the whole energy-system of the city. The citizen will be the heart of the system as a conscious consumer, as a part of a new mobility-management or as a producer of electricity and heat. He becomes a "prosumer", who will become sensitive for the issue energy because he knows and understands the consequence of individual operations.

The energy-model can be enhanced yearly in the project-phase and shall be used as a foundation for planning and decision-making. The model can also be used to review former actions and to analyse the energy consumption of existing service-products and -processes. The developed concepts for mobility and electricity-/heat-supply can be used by the city- and traffic-management and/or the energy supply company as a basis of decision-making. A later transfer to other cities is also possible.