Does the Electricity Authority keep data on which thermal generation plant sets the marginal electricity spot price most often, if so, what does it show?

Answer

I am advised that the Electricity Authority monitors and publishes information on the marginal generator weekly in its Trading conduct reports, which can be found on the Electricity Authority’s website. In the last two years from 1 June 2024 to 1 June 2026 thermal generation has set the spot price 6.39% of the time. Of these times, Huntly unit 5 set the price most often at 30% of the time, or about 2% of the time overall.