The Stirling engine ... this mysterious and unknown object

The Stirling engine is a heat engine in which the movement of the pistons is driven by the heating and subsequent cooling of a gas (generally helium or hydrogen). This continuous change in temperature of the gas generates its expansion and subsequent contraction. The alternating expansions and contractions of the gas activate the movement of the 2 pistons and in this way the thermal energy is converted into mechanical energy. The latter, with the use, for example, of a dynamo (the very simple one of bicycles), can be converted into electricity!

On the web, for little money (20-50 euros), you can buy toy models of Stirling engines. The following video is an example.

On wikipedia the behavior of the gas is explained as follows:

“When a sufficient temperature difference is reached between its hot spot and its cold spot, a cyclic pulsation is triggered (suitably initiated at the beginning), normally transformed into reciprocating motion by pistons. The pulsation lasts as long as the temperature difference continues to be maintained, supplying heat to the hot spot and subtracting it from the cold "

Well ... does the phrase "give heat to the hot spot and remove it in the cold" remind you of something? Isn't there already something in our homes that can give and take away the heat of a gas?

In a previous article (the heating system) I explained that a heating system generally works with a flow temperature of 70-75° and a return temperature of 60-65°. What do you think? Would these two temperatures be capable of running a Stirling engine? And with this Stirling engine would we be able to produce electricity at home?

It may seem strange to you… but someone has already thought about it and built some very simple gas boilers also equipped with a stirling engine. The result is a boiler that produces hot water for our heating system and at the same time also electricity (generally 1 kW of electricity). This simultaneous production of thermal and electrical energy is called micro-cogeneration or CHP (Combined Heat and Power).

Consider that in Italy, hypothetically replacing the entire installed park with micro-cogeneration boilers could lead to a CO2 reduction equal to almost 20% of the Kyoto targets.

Why is there so little talk about it? Or rather, why do we continue to speak only of photovoltaic systems for the production of electricity at home? What interests lie behind this trend?

The final judgment is up to you!

P.S. source of images and videos: web