Wet summer keeps hydro lakes full

A wet summer has kept Meridian's hydro storage lakes topped up, which could help keep power prices in check down the track.

Record rainfall in both the North and South Islands in January saw flows coming into the lakes exceed historical averages.

Meridian spilled from both its Waitaki and Waiau schemes throughout December and January, with national storage falling from 135 percent to 117 percent of the historical average.

"Wholesale electricity prices through the month of January were as low as I ever remember them being - they were $1 per MWh which is, you know, [basically] free," chief executive officer Mike Roan said.

He said lower wholesale prices were down to both the large amount of rain and investment in new generation into the system.

"Hydro lakes are fuller than they'd normally be this time of year, which bodes well as we approach winter.

"[The lakes] hold about four months of water and they're above average.

"So we've got a lot of fuel in the system right now, but you jump four months ahead - that's kind of end of June, early July - so we can see most of winter, which is great, and in a month's time, we'll be even more confident."