The Politecnico di Milano in its Energy Efficiency Report compared the economic convenience of the different solutions forenergy efficiency taking into account in particular the Pay-Back Time, but net of incentives. The result shows that the best solution varies according to the application field, residential, industrial or tertiary, and that in general there is an optimal mix of technologies forenergy efficiency. Let's see which ones.
There cogeneration is the technology forenergy efficiency more convenient in the industrial field to meet the thermal needs and part of the electrical needs. Systems of cogeneration can contribute toenergy efficiency in industry to replace the generation of thermal energy through traditional boiler and the supply of electricity from the grid.
There condensing boiler is the technology forenergy efficiency more convenient in the residential area to meet the thermal needs. This solution is more efficient than using other solutions such as heat pumps is solar thermal, limited to the need for domestic hot water.
There heat pump is the technology forenergy efficiency more convenient in the tertiary sector to meet the thermal needs. A system of this type is more efficient than condensing boiler and solar thermal, limited to the production of hot water, but there are exceptions. In hospitals and hotels, the most convenient solution is the cogeneration, which also meets part of the electricity requirement. In schools, where the buildings are not used all year round and not even every day of the week, the generation of thermal energy through the traditional boiler methane gas, together with the supply of electricity directly from the network.