We may be a nation of sun-worshippers but when it comes to forecasting where the sun shines longest, Australia’s energy authorities are stuck in the dark ages.

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The CSIRO is hoping to fill that information void with a lot more riding on it than the best place to get that tan. Energy energy suppliers – current and future – need the data to predict how much solar electricity is likely to flow through the nation’s power grids.

For potential developers of large-scale solar power plants, radiation records are needed to bolster investment certainty as they try to secure finance from bankers or government agencies. The real urgency for hard numbers, though, is coming from the rapid take-up of solar photovoltaic (PV) panels, with the total now approaching 900,000 across the country.

“It’s essentially an unknown quantity what those cities full of roof-top PV are producing and we’d like to be able to forecast it,” said Peter Coppin, the senior renewable energy researcher leading CSIRO’s bid.

The Australian Solar Institute, due to be rolled in to the larger Australian Renewable Energy Agency (ARENA) at the end of the year, has earmarked funds for solar resource forecasting techniques.

The ASI funding will be announced within weeks with CSIRO and its partners’ bid seen likely to succeed. The institute co-sponsored a talk yesterday by Dr Coppin at the Sydney offices of law firm Baker & McKenzie.

The Australian Energy Market Operator (AEMO), a member of the bid consortium along with the Bureau of Meteorology, installed an advanced forecasting system for wind four years ago to help it manage a big increase in wind farms.

Capacity reached

Dr Coppin said the wildfire spread of solar PV is already straining the power grids of some regional areas, with so-called “hosting capacity” being reached.

WA’s government-owned Horizon Power, for instance, is restricting new capacity in some towns such as Carnarvon where the grid can’t cope with the intermittent supply that comes with solar power.

‘‘There’s been a huge up-take of solar in Carnarvon,’’ a Horizon Power spokeswoman said.

The problem is not just one of ageing grids initially built to carry power only from the utility to the consumer, but also the amount of solar energy being generated, Dr Coppin said.

“If you’ve got a lot of intermittent generation on an electricity grid, you really have to know when it’s coming to officially schedule the rest of the generation,” he said.

The ASI has alone invested $150 million in 60 solar projects around the country and there are at least two more large-scale solar projects approved, as the emerging technology takes hold across the sunnier regions of the country.

Earlier this month, First Solar, the world’s biggest maker of thin-film panels, officially opened its 10-megawatt Greenough River project in Western Australia, the nation’s first large-scale solar plant. The solar project, owned by General Electric and Verve Energy, may quadruple capacity.

According to AEMO’s 2012 report on national forecasting, rooftop PV will supply 3.4 per cent of annual energy generation by 2021 – although tumbling panel prices may see that tally exceeded. A separate recent government report tipped solar PV and onshore wind to have the cheapest generation costs by the mid-2030s.

The funding bid, which also includes the Bureau of Meteorology, universities and German and American groups, would aim to deliver the new mapping system by the end of 2014, Dr Coppin said.

“By two years’ time, when we’ve got something in place, it will be just in time,” he said.

With Bloomberg.