The Powerhouse was the 2nd biggest structure at the Marconi Station.
Its uses had several functions in order to produce the power necessary to operate the Marconi Station. The powerhouse manned and operated 24 hours and 7 days a week. The powerhouse was operated by engineers and turf workers. The powerhouse was situated overlooking Lough Emoulcourthy. The powerhouse was divided into 3 sections; engine room, operations room and fuel shed. The powerhouse materials and components were sourced from England. The narrow gauge 2 foot railway serviced the powerhouse by supplying peat to fuel the generators. A manual crane placed adjacent to the powerhouse was used to unload peat from the rail carriage thus storing the peat in the fuel shed ready for supplying fuel for the powerhouse.
The lake beside the powerhouse was used to cool the turbines and alternators to prevent overheating the operation of the alternators and boilers. The powerhouse included 5 to 8 boilers that produced power to the alternators to generate to 50-60 horsepower to transmit power to the conedensor house for transatlantic radio signal transmission. There were six chimney stacks overlooking the powerhouse in total which released steam and smoke from the burning of peat in the boilers. The chimney stacks ranged from 10 to 80 foot in height. Pipes situated underneath the powerhouse were used to transmit the fuel to the condenser house and also to carry water from the nearby Lough Emoulcourthy to cool the generators. A massive pumping station was situated between the lake and powerhouse in order to pump water towards the powerhouse generators to cool the boilers operations. The structure of the powerhouse was a wooden structure casing.
The floor and foundation base was of concrete structure and this is still evident today. The boilers, alternators, pipes and turbines were of cast steel iron material. 2 to 3 huge battery terminals were housed in a chamber inside the powerhouse used for generating the electricity for the Marconi Station. The massive alternators and turbines were 12-15 foot long and weighed 15 tonnes in weight. The alternators and turbines were transported by ship from England to Clifden harbour then transported by horses and carriage from Clifden harbour and then finally transported by the Marconi narrow gauge railway about 2-3 km nearer to the Marconi Station. The powerhouse was also used for generating electricity for the whole Marconi Station site along with the residential and workers houses. Alcock and Brown who crashed landed near the Marconi Station were given a tour of the powerhouse while they were recuperating after their historical transatlantic flight. Sadly the powerhouse was destroyed by fire in 1922 during the Irish Civil War.