Topped-up lakes have generator smiling

Hydro lakes are full and one of the country’s main generators says there is a sign that prices will get more affordable as a pipeline of massive investment in renewable projects comes online.

The weather has been all over the place in recent months but plenty of rain has put the hydro lakes operated by Meridian Energy in good shape.

It operates the Waitaki system and the Waiau River system to feed the Manapouri power station.

The company said hydro storage was holding close to historical averages despite softer monthly inflows. At the same time, ASX forward prices have declined further, likely reflecting the high levels of investment in new renewable generation and the system security provided by agreements signed for Huntly capacity.

‘‘We’ve maintained momentum through the March quarter after a very strong half-year result and the lakes are looking really good as we get closer to winter. These things can change, however at this stage we have 40% more water than we did at the same time last year,’’ Meridian chief executive Mike Roan said.

‘‘The continued fall in ASX prices is significant and a sign that power will get more affordable as the massive ongoing investment in new renewable generation lands. We expect this to flow through into contracted electricity prices.’’

ASX forward prices are the traded settlement prices for electricity futures contracts on the ASX platform, allowing participants to buy or sell electricity at fixed costs for future dates.

Meridian Energy said in the month to April 13, national hydro storage decreased from 110% to 106% of historical average.

South Island storage decreased to 97% of average and North Island storage increased to 180% of average by April 13 2026. Cyclone Vaianu had dumped rain across much of the North Island in the preceding days.

Meridian’s March 2026 monthly total inflows were 74% of historical average.

To date this financial year, total inflows were 123% of historical average, the sixth-highest financial year inflows on record.

Meridian’s Waitaki catchment water storage at the end of March 2026 was 99% of historical average.

Water storage in Meridian’s Waiau catchment was 73% of average at the end of March 2026.

March was mild and mostly settled, with temperatures above average for large parts of the South Island.

National electricity demand in March 2026 was 4.5% higher than March last year.

New Zealand Aluminium Smelters Ltd (NZAS) average load during March 2026 was 575MW, compared with 524MW a year ago, when Meridian and NZAS had agreed a 50MW demand response reduction from March to August last year.

Meridian’s retail sales volumes in March 2026 were 11.4% higher than March 2025.

Last summer was influenced by weakening La Nina conditions. It had a warm start, transitioning to a cooler February and generally near-average temperatures overall.

The country experienced active summer weather patterns, with periods of high pressure interspersed by heavy rain events that brought record rain to parts of both islands.