"When you start to combine wind and solar in an intelligent, optimised way, then you can provide much greater penetration of renewables into the grid," Price said in a phone interview, adding that the facility expected to start up in two or three months.

Price said combining wind and solar allowed the project to save on connection costs to the network, while enhancing grid utilisation because the wind generally blew at night when solar wasn't available. In addition, Kennedy has potential to supply more power to the grid than its 50 megawatt transmission line can handle, so the battery will allow that excess power to be stored.

A range of co-located projects have followed in Kennedy's wake, with 690 megawatts worth of capacity commissioned across the country, BNEF said in a report last month. In January, a joint-venture between Lacour Energy and a unit of Xinjiang Goldwind Science & Technology Co won approval for the $250 million Kondinin complex in Western Australia, which will combine battery storage with 120 megawatts of wind power and 50 megawatts of solar.

French company Neoen has even bigger ambitions: Its Goyder South project in South Australia, which is scheduled to begin construction in 2021, is on a scale not yet seen for a renewables project in Australia. It includes 1200 megawatts of wind power and 600 megawatts of solar backed by 900 megawatts of battery storage.

It's not only Australia that is developing the concept. In the US, NextEra Energy is working on two projects that combine the three technologies, while Vattenfall is working on a "triple-scoop" project in the Netherlands believed to be the first of its kind in Europe. India is also keen on the idea, with the government putting policies in place to encourage co-located projects in a number of states, according to BNEF.

The site of Windlab's Kennedy Energy Park, where the wind blows mostly at night.

"Whenever we are kicking off a photovoltaic or an onshore wind project in the future, we will always consider whether we should do it as co-located," Alfred Hoffman, a vice president at Vattenfall's wind unit, said at a BNEF summit last month in London.


There are various constraints to developing such integrated projects. In Europe, for instance, most large-scale wind and solar is procured through auctions, which aren't currently designed for co-located projects, according to Cecilia L'Ecluse, a solar analyst at BNEF in London. There can also be permitting issues, such as Germany's ban on using farmland for solar, while in the US, developers may not be facing the same grid access challenges, so the savings incentive might not be as strong, she said.

Windlab's Price acknowledged that combining technologies would only work in certain locations and, in a modern well-connected grid, wind and solar don't necessarily need to be on the same site to deliver combined benefits. It could be in developing countries where the concept could make the biggest difference, said Price, who's also working on an 80 megawatt multi-technology project in Kenya. It's also a particularly pressing problem in countries like Australia, where a number of ageing coal-fired power stations are scheduled to retire over the next decade, leaving renewables to fill the gap.

"In the future, we won't have these big fossil-fuel plants to keep the grid stable. That's an additional task that renewables will have to take on," said Bo Svoldgaard, senior vice president of innovation and concepts at Vestas Wind Systems, which partnered Windlab on the Kennedy project and supplied the turbines. "The fossil fuel plants will disappear. Maybe not tomorrow, or in two years time, but they will disappear."

Bloomberg