A 62MW solar farm is to be built on the old ash dam of the Vales Point power station in New South Wales, after its owner Delta Electricity signed a 10-year off-take agreement with New York based Enernet Global.

The deal stock by Delta, half owned by outspoken coal and nuclear advocate Trevor St Baker, is deliberately calibrated to coincide with the expected closure of the Vales Point coal generator, although it could be extended if St Baker succeeds in his goal of getting government support to extend the life of the coal plant.

The deal is the first in Australia for Enernet, which focuses on “distributed” solar plants in Australia, the Philippines (where it has two solar plants under construction) and in the Caribbean,

Simon Gamble, who previously played a senior role at Hydro Tasmania, where he oversaw the installation of hybrid systems on King and Flinders Island, is the head of Enernet in Australia and chief operating officer for the global group, where he has engineering responsibility for all operations.

He said the Vales Point solar plant will use innovative technology from US-based Alion Energy, using a special shallow concrete foundation and A-frame mountings for the tracking system. This allowed it to dodge the highly caustic sub soil caused by the ash tailings. “We don’t have to drive piles that wouldn’t last long,” he told RenewEconomy.

In a joint statement, the two companies say the 62MW (DC) plant (about 50-55MW AC) will deliver around 87GWh of solar a year to Delta, while the rest of the output – expected to total 120GWh – will be sold into the market. The solar plant is due for completion by the end of 2020.

It’s a little bit ironic that one of the few solar PPAs in recent months should be signed by St Baker’s Delta, given that he has warned of the dangers of having too much solar and wind in the grid.

But Delta argues that the location, close to networks and load centres, makes it ideal. There is scope for the solar farm to be expanded, but one suspects this wouldn’t happen until the future of Vales Point itself is clear.

Delta says it will use power from the site in its retail business. ensuring a significant contribution to state and federal government renewable energy targets. It is the first significant step for the company into the renewables business.

“The partnership with Enernet recognises that both dispatchable power and low emission technologies have a role to play in supporting an affordable, reliable and sustainable national electricity grid”, Delta CEO Greg Everett said in the statement.

”The Vales Point site is an example of how both technologies can be co-located and integrated into the grid”.

Gamble said the Vales Point project will pave the way for Enernet to deliver similar plants in other challenging sites across Australia, including other ash dam sites, mining tailings dams and municipal landfills.

“Our primary aim is reducing energy costs to clients, either through gas and diesel displacements at mine sites and tourist installations, and in the agricultural sector.”

Paul Matthews, the global head of Enernet, said he saw Australia as a core market.