The price impacts of supply side shocks in energy markets can be enhanced in concentrated markets through the exercise of market power, and can be acute in markets undergoing transition due to imperatives such as decarbonisation. In a recent book chapter,  we explore how gas supply constraints associated with commencement of LNG exports in 2015 together with a progressive market concentration due to closure of old coal plant resulted in a ‘perfect storm’ that contributed to a doubling of wholesale electricity prices. This seminar presents the finding of this work, and  highlights the disproportionate impact of gas prices, which has been exacerbated through the exercise of market power, especially via the practise of ‘shadow pricing’.