7 Micro Gas Turbines

Conventional gas turbines (GTs) range from a size of one or a few MWe to more than 350 MWe (GTW, 2009). Those at the small end of the range are commonly used in industrial applications, for mechanical or onsite electrical power production, while the larger ones are usually installed in large-scale electrical power plants, often in combined cycle plants, and are typically located far away from the consuming region. In the future distributed energy systems based on small local power plants are likely to spread; since they lie close to the final users, they reduce electrical transport losses, and make thermal energy recovery profitable both in energy-related and in economic terms (Papermans et al., 2005; IEA, 2002). These benefits explain the increasing interest in smallsize generation systems. Recently, gas turbines < 1 MWe, defined as micro gas turbines (MGTs), have appeared on the market. MGTs are different from large GTs and cannot therefore be considered merely as their smaller versions. Their advantages as distributed energy systems lie in their low environmental impact in terms of pollutants and in their competitive operation and maintenance (O&M) costs. MGTs appear to be particularly well suited for service sector, household and small industrial applications (Macchi et al., 2005; Zogg et al., 2007).