Today, the organ sits disassembled, undergoing what may be its last overhaul, as plans are underway to replace it with a digital organ sometime after 2025. That will doubtless cut the power bill down mightily, because modern loudspeaker transducers produce vastly more acoustic wattage than blowers pressurizing wooden wind boxes.
Still, the designers will be hard pressed to beat the acoustic fuel economy of this system, seen and heard playing Bach's Dorian Toccata at an energy cost of roughly a pint of ale:
