In September, the Australian Renewable Energy Agency (Arena) announced the winning projects in its multi-million dollar large-scale solar round, which will triple the country's solar capacity.
One of the chosen 12 projects is the 20MW White Rock Solar Farm, which Goldwind Australia is developing adjacent to its White Rock Wind project, currently under construction in New South Wales (NSW).
The hybrid solar and wind farm is one of several projects under way across Australia.
In July, Goldwind also announced it was building a 10MW solar project next to the 175MW New Gullen Range wind farm, in which it has a 25% share.
Both the Gullen and White Rock solar projects will benefit from sharing part of the wind-farm infrastructure, including substation, switchgear and access roads. Co-location could save as much as A$6 million (US$4.4 million) for Gullen and A$5 million for White Rock.
In March, consultancy and engineering firm Aecom published a study, on behalf of Arena, investigating and quantifying the benefits and cost savings of co-locating solar and wind farms.
The technical capacity of existing wind farms able to accommodate co-located solar farms is estimated at more than 1GW across Australia.
The greatest brownfield — retrofitting solar at an existing operating wind project — co-location opportunities are in Western and South Australia, states with good solar resources, a complementary generation profile and higher wholesale market prices.
The best greenfield opportunities for wind-solar co-location — where both are developed together — are to be found in the same regions, as well as parts of Queensland and some of NSW.
From a Capex perspective, cost savings at greenfield sites can be achieved during the planning and development phases.
The fixed costs of any studies can be shared between the two projects, including transport and labour for site visits, geotechnical studies, ecological and heritage investigations and local community and stakeholder meetings.
Substantial savings on grid connection costs can also be achieved. For a greenfield project, one substation needs to be built, as opposed to two, with allowance within the substation made to accommodate both technologies. Aecom's study estimates Capex savings of up to 13%.
Opex savings can be as much as 16%, according to the study. This is down to efficiency gains, mainly due to sharing facilities for operations and maintenance (O&M). Although skill-sets are different for each, wind farm O&M teams, which tend to be larger than for solar PV, can be deployed to inspect both.
Challenges may arise over a shared grid connection point if a problem with the wind farm means that electricity from either project cannot feed into the grid. "Then there has to be a way to compensate the solar farm owner and vice versa.
However, these are small issues, compared with the overall cost savings and efficiency gains that are possible," said Craig Chambers director of power generation at Aecom.
Improved yield is also made possible by co-locating solar and wind farms, particularly in regions where there is not much wind blowing in the daytime and where the solar resource is relatively high. "That sunken investment — the grid connection equipment — is optimised," said Chambers.
Juwi Australia, which develops solar PV farms, is working on several projects to co-locate solar PV with wind.
In many cases the wind farm operator or developer, if it is a greenfield site, has approached Juwi where co-location makes sense commercially, said the firm's managing director Andrew Drager.
"They are good at wind and we are good at solar, so if it makes sense commercially then they are interested in working with us, especially if co-locating wind and solar creates a better profile for the off-taker as well," said Drager.