Power prices against the weather
Wholesale electricity prices for every half-hour, set against temperature and wind in four cities and the mix of what generated the power. Prices and weather are piped into a data lake each day; the generation history was restocked from monthly files.
Connecting to the warehouse…
Every half-hour for 30 days
One row per day, one column per half-hour from midnight to midnight, New Zealand time. Dark is cheap, bright is dear. The evening peak and the cheap overnight valley show up as vertical bands.
One country, two prices
Power is cheap where the hydro lakes are and dear where the people are. When the link between the islands fills up, the North Island pays more.
Does cold push prices up?
Each dot is one day. Temperature is the average of Auckland, Wellington, Christchurch and Dunedin. The correlation runs from −1 to +1, where 0 means no link. With only a season of data, treat it as a first look.
Generation by fuel
Monthly generation from every station on the grid. These numbers arrive as monthly files after each month ends, so they trail the prices by up to a month.
Three sources, one lake
Each source lands in the lake as raw files first. The warehouse is built from those files, and can be rebuilt from them. The figures below are read live from the pipeline's own records.
Piped in and restocked
Prices and weather are piped in: a schedule asks for whatever is new and files each answer. The first time it ran, the schedule worked backwards a few days at a time until 90 days of prices were in.
Generation is restocked: the Electricity Authority publishes one big file per month, so the lake takes each file as it appears and the warehouse adds up the stations by fuel.
Good to know
- Prices are for two hub nodes: Otahuhu in Auckland and Benmore in the Waitaki valley. Each of the roughly 250 grid nodes has its own price.
- Prices marked interim are replaced by the final file when it is published, usually a day or two later.
- Times are New Zealand time. Days when the clocks change have 46 or 50 half-hours and are shown as 48.
Prices and generation: Electricity Authority, EMI (CC BY 4.0). Weather: Open-Meteo.com (CC BY 4.0). Analysis by Tom Rowley. A demonstration of a data pipeline, not trading or hedging advice.