Our World: Capstone Turbine Corporation

The year 2021 will mark the twentieth anniversary of the partnership between IBT Group and Capstone, a leading Californian company and the only manufacturer in the world of energy systems with gas turbines with “oil-free” technology, of which IBT is the exclusive distributor for Italy. Founded in 1988, Capstone, with over 100 registered patents, develops, manufactures, sells and does maintenance cogeneration systems: the combined production of electrical and thermal energy, enabling heat recovery. Capstone is committed to improving the efficiency of energy needs worldwide, while reducing global emissions of pollutants and greenhouse gases. Capstone’s systems help end users improve their impact on the environment by meeting power and reliability needs. To date, Capstone has shipped nearly 10,000 units to 83 countries and saved customers approximately $219 million in annual energy costs by avoiding the emission of as much as 368,000 tons of carbon into the atmosphere.

Among the areas of application of Capstone systems designed and implemented by IBT Group are the hotel, food & beverage, textile, paper, hospital and pharmaceutical, retail & office, biogas from digester, landfill, district heating sectors.

The patented “oil free” technology, from aerospace derivation, is the result of more than ten years of research that has developed an important and unique technology, given by the complete absence of lubricating oil in the special bearings that help to support the shaft of the turbine in rotation without mechanical contact. These bearings operate on a film of air that is generated by specific aerodynamic profiles that are located on the axis of the turbine. Therefore, friction occurs only during the start-up and shutdown phases of the machine. These friction moments are also defined as stress-free as they are cushioned by a specially designed support structure that ensures durability and functionality of the mechanical parts.

Capstone turbines simultaneously generate electrical and thermal energy in the form of hot air. Through specific applications, thermal carried in the form of exhaust gas could be convert to the process uses needed by the user, as saturated steam, hot air for drying process, freezing or chilled water for trigeneration system. An example in this last case, the system with Capstone uses hot water obtained with the above transformation, conveyed in a Century absorption refrigerator which, through a specific transformation process, uses it to produce chilled water then used in an air conditioning system.

The Capstone gas turbine allows a great flexibility of use both for the variation of the biogas flow rate and for the variation of the methane concentration: the system allows a modulation of the electric power from o% to 100% of the nominal power.

For any structure / industry that is subject to a seasonality of energy needs, the plant with Capstone turbine allows the modulation of energy production following the peaks of demand.  This result is obtained by varying the speed of rotation of the turbine from beginning of generation to 96,000 rpm (rated power).

Thanks to their “oil free” design, the turbines have the lowest emissions of pollutants into the atmosphere available today (NOx < 9 ppmV / < 18 mg/Nm3) allowing their installation and use without any catalytic or SCR system to abate the pollutants emitted. In terms of investment, against an initial expenditure, the recovery is between 2 and 5 years. The reduction in consumption alone is considerable, we are talking about more than 30%. Finally, the simplicity of the cogeneration arrangement based on the Capstone turbine package, the “oil free” technology, the absence of refrigerant liquids, the absence of the catalytic emission abatement system, determines a drastic reduction in both maintenance costs and the plant downtime required for the same. The modularity of Capstone systems allows you to perform maintenance to a turbine while the others continue to work.

For after-sales service, Capstone espouses IBT’s values of attention and care for the customer. Through FPP “full service” contracts, once the system is installed, at least 10 years of maintenance are guaranteed to maintain the same level of savings and efficiency of the system.

To date, more than 250 Capstone turbine systems have been installed by IBT Group, for a total of 25 MW of electrical power.