Résumé : We all take for granted that if we press the switch, the lights turn on; that to charge our phone we just need to plug-in the charger and that food is always safely stored in our fridge... but what would happen in the event of a blackout? are we really conscious of how much we rely on electricity? could we survive without it, even for a few days?The current electricity network is strongly centralised, with electricity generated in large power plants and distributed through transmission networks to the final consumers. With increasing energy demand and renewable energies entering the scene, centralised systems have proven to be very stiff: lacking the flexibility to adapt to sudden demand fluctuations and being unable to deal with strong peaks, with the consequent risk of blackouts.Small, decentralised energy systems can be placed closed to the consumers, avoiding distribution losses and adding flexibility to the network. In particular, small cogeneration units can simultaneously generate heat and electricity; thus, also fulfilling our heating requirements and increasing energy efficiency. However, when there is no or little heat demand (e.g. during the summer), the heat produced by the cogeneration engines cannot be utilised and they need to be shut down. This is the reason why small-scale cogeneration cycles are rarely seen and have not been widely adopted yet.This PhD focuses on the injection of water in a specific small-scale cogeneration technology, the micro gas turbine (mGT) cycle. Thanks to water injection, the production of heat and electricity is decoupled; therefore, the operation of the units is not anymore dependant on the heating demand and they can be used any time during the year. The objective of this thesis is to analyse the numerical, experimental and economic aspects of the so-known micro Humid Air Turbine cycle. The aim is to bring mGTs closer to the market so as to contribute to a more secure, future energy network, where blackouts are avoided at all times.