The level of development of the energy sector plays an important role in other sectors of the economy as well as on the national economy in general. The energy sector must be sustainable and must be based on the use of energy-efficient technologies. Energy efficiency in sources of energy is one of the priorities of Latvia in the field of energy and one of the tasks of the energy strategy in the European Union. This article offers an innovative solution for increasing energy efficiency in sources of energy by using an environmentally friendly chimney. The proposed technology focuses on the reduction of heat loss from exhaust flue gases using flue gas cooling with supplied air. One of the characteristics of the system is related to the use of environmentally friendly plastic material for the chimney outer pipe. The article reflects the justification of the proposed solution, as well as the planned methodology for research.