In June 2007, Wärtsilä and EuroPower SpA commenced operation of a 24 MW combined heat and power (CHP) plant at Linate airport, Milan in Italy.
The plant is built for Malpensa Energia Srl, whose shareholders are the Milan airport management company SEA Aeroporti Milano and the Milan multi-utilities company AEM Milano (currently “a2a” after merging with ASM Brescia). The combined heat and power plant is equipped with three Wärtsilä 20V34SG gas-fuelled generating sets, together with their ancillary equipment, exhaust heat recovery economizers and two gas-fired boilers. The plant is located inside Linate airport area.
The plant operates on baseload but, by providing both heating and electricity, it is designed to flexibly and economically meet the variations in heat demand in summer and winter. The heat output of the plant is 82 MWth in winter and 72 MWth in summer, with a year-round electrical power output of 24 MWe.
The heat recovery system for the three engines is designed in order to maximize district heating water production for maximum heat recovery for heating services and in the future for the air conditioning of airport buildings. This full climate control system is typically referred to as a trigeneration installation. Trigeneration is generally understood to mean simultaneous conversion of a fuel into three useful energy products: electricity, hot water for heating and chilled water for cooling.
The heat is delivered as hot water at 125°C and 70°C to the airport buildings and also to households of a small village close to the airport. The plant also delivers electricity to the Italian national grid. Normally the generating sets run in parallel with the grid but they also serve as emergency sets to maintain airport services in the event of a break in the grid supply.
Power and thermal energy needs are huge in new air terminal buildings. At an airport it is of utmost importance that power and thermal energy is available at all times of the year, independent of external factors. A trigeneration plant can provide electrical power as well as heating and chilling for these buildings in a single power and energy source on-site, providing significant operational and efficiency advantages since separate systems are not necessary.