Glowing terms ... the $1 million mobile grids have been utilised to help prevent a mudbath.

Glowing terms ... the $1 million mobile grids have been utilised to help prevent a mudbath. Photo: Seven Network

THESE are the $1 million grow lights purchased from the Netherlands to help ANZ Stadium cope with winter conditions in Sydney and it is unlikely the ground's surface will have faced a greater test than tomorrow night's State of Origin.

After 100 millimetres of rain fell at Sydney Olympic Park over 24 hours from noon on Sunday, Paul Gallen may have been leading the Blues team out onto a mud heap without the aid of the mobile lighting grids.

Remarkably, given that Sydney received more rain yesterday than any day for five years, stadium officials reported there was no surface water on the ground.

Mobile grid.

Mobile grid. Photo: Seven Network

With clearing showers forecast for tomorrow ahead of a fine night, officials are hoping a capacity 83,999 crowd will be on hand to cheer NSW to a series-levelling win over Queensland and the game is expected to be officially declared a sell-out today.

As the stadium was built with a sand profile, the surface drains quickly but it will be damp so slippery conditions are guaranteed.

Venue spokesman Arthur Stanley said the grow lights were used regularly in winter to improve turf growth.

The lighting system consists of mobile grids that sit above the playing surface and ANZ Stadium has six large units and two small units to help overcome severe shade patterns and poor air circulation.

The same technology is used at Cardiff's Millennium Stadium, Twickenham in London and Melbourne's Etihad Stadium.

Meanwhile, an additional 1200 seats have been installed at ANZ Stadium to ensure the biggest Origin crowd since the venue was reconfigured after the 2000 Olympics.

The stadium holds the record for the biggest Origin crowd after 88,336 fans turned up to cheer NSW to a 12-8 win in the second match of the 1999 series.

Stanley said only a few hundred tickets remained available for Origin II and they are expected to be snapped up today.