The former plant’s boiler annexe east, close to the station’s iconic chimney, was “blown down” in calm conditions on by ScottishPower’s demolition contractor Brown & Mason.
Longannet was closed in 2016, marking the commitment by both ScottishPower and parent company Iberdrola to decarbonise the economy.
More than 28,000 tonnes of material has been removed from site so far, of which 98.5 per cent is said to be set for recovery and recycling.
ScottishPower says it recently became the first integrated energy company in the UK to shift completely from coal and gas generation to 100 per cent renewable energy.
Globally Iberdrola aims to reduce emissions by 30 per cent by 2020, and 50 per cent by 2030, compared to 2007, and be carbon neutral by 2050.