Powering up irrigation storages to solve the evaporation enigma

With the support of the cotton industry, water storages around Australia could soon dramatically reduce evaporation losses and become renewable energy powerhouses.

 With support from CRDC, Ag Econ Australia’s Jon Welsh secured $6 million from the Federal Government toward the $13 million Novel energy and evaporative storage technologies for irrigators project. It was one of eight chosen by the Government from 120 submissions under the Department of Agriculture, Fisheries and Forestry’s Future Drought Fund Resilient Landscapes program.

“By relocating just half of the 16.6GW grounded solar panels currently sitting on land to water storages could save 296GL of water a year – equivalent to a full Glenlyon Dam – and generate vast quantities of clean energy in the process,” Jon says.

The Future Drought Fund supports Australian farmers and regional communities to build their drought and climate resilience. In terms of water security, evaporation causes the largest component of loss from rural and urban water storages in Australia, usually between 30 and 40 per cent. Not only does this represent a huge loss, it means water storages are highly susceptible to drought, or it is uneconomical for farmers to store water in some regions due to evaporation losses.

This project will cover suitability for floating solar photovoltaic panels (FPV) in the cotton, wheat, sugarcane, macadamia and rice industries. This extensive project is a collaboration between CRDC, Ag Econ, researchers from Macquarie University and the University of Southern Queensland (UniSQ), CRDC’s sister Research and Development Corporations (RDCs) Sugar Research Australia (SRA) and Horticulture Australia, and a host of commercial irrigation farmers who are willing to provide case study data. 

Jon Welsh says the project has huge potential to ‘shift the dial’ on evaporation losses and energy emissions abatement across the cotton industry.

“We are really excited about the impact of this work, as Australia faces a critical trilemma of securing water, food, and clean energy. Incorporating floating FPV on storage dams will help address all of those challenges simultaneously,” Jon said.

“Cotton is really leading the way in Australia by years of previous research.

“We know FPV projects can work. We’ve seen it done overseas, and domestically with two utility-scale FPV projects in Australia, but there are serious challenges and a critical research gap remains - and that is how to develop a practical and cost-effective solution ready for farm rollout.”

This includes everything down to looking at how to run power generated through the FPV panels into the transmission network, the creation of potential Renewable Energy Zones where storages exist, understanding what happens in low water level scenarios, plus cleaning, economics and policy incentives.

Opening new opportunities

“We know these floating panels have a big impact on evaporation because they disrupt both sunlight and air flow across the water, but more work needs to be done in an Australian context,” Jon says.

“At the same time, their ability to generate renewable energy offers not just a source of sustainable on-farm energy, but there could be emission abatement and alternative income opportunities as well.

“It wouldn’t take many 30 MW arrays on dams, provided attribution could be met, to make substantial gains on the carbon balance sheet and enhance sustainability credentials across the supply chain.”

The shift in focus to floating PV has been enhanced by the evolution of Virtual Energy Networks (VEN) that means the electrons generated can be shared across multiple sites in different geographic locations. This is a game changer for the economics of investing in this technology.

“This is really exciting as FPV could provide a new revenue stream for landholders during times of drought or could offset energy generation from the field to an office in town.

“VENs overcome barriers like the tyranny of transmission distance, power purchase agreements and other commercial constraints that have precluded adoption in this area. 

“It’s early days, but the barriers to entry with VEN have been lowered, and many water storage facilities used in agriculture and local government areas for town water supplies have more options now than ever. This project will provide much-needed research including pilot studies and gathering on-site data and an understanding of key constraints.

The viability of using FPVs on water storages to create sustainable energy and mitigate evaporation will be investigated. The project will also look at opening regulatory pathways to ensure the findings of the research can be implemented, alleviating the impacts of evaporation and drought or low rainfall years. To aid in the preparedness of adapting to extreme climatic events and episodes that influence access to surface water, the researchers will work with Cotton Grower Associations and the National Irrigators Council to better understand what drives inflow-generating rain events in regulated storages used by irrigators, across eastern cropping regions.

Australian water productivity has doubled over the last 25 years with half as much water now being used to produce a bale of cotton. Long-term irrigation benchmarking studies, conducted by NSW DPIRD with the support of CRDC, have shown that drought conditions have affected the rate of long-term improvement in the gross production water use index (GPWUI) due to increased water demand and reduced yield. This illustrates the vulnerability of irrigated cotton to climate change.

CRDC’s 2023-28 Strategic RD&E Plan, Clever Cotton, outlines CRDC’s focus on actions to strengthen capacity for adaptation to climate change and make farms more resilient to shocks.

CRDC Senior Innovation Broker Susan Maas supported the submission and will oversee CRDC’s involvement.

“This is very exciting as evaporation is a big-ticket item for our us in our Strategic Plan, and there is also an element of huge public good in this project,” Susan said.

“For the cotton industry specifically, so many gains have been made in irrigation efficiency over the past 30 years thanks to our researchers and growers. But we are now at the incremental gain stage, until game changing research comes along. This project has the potential to create transformational change.

“Evaporation from on-farm storages and delivery systems is the last hurdle in terms of improving water use efficiency. There are huge gains to be made.

“While research and development has created technology and knowledge for irrigation optimisation, our inability to find a practical solution to evaporation from storages – despite the length of time we’ve been looking at it – has affected our ability as an industry to continuously improve our water use efficiency.

“The addition of renewable energy generation on farm storages is an incredible co-benefit of this solution to evaporation.

“The co-designed approach to this project aims to deliver significant ag community and irrigator benefits, like strengthening income for farmers, and enhancing the resilience of energy infrastructure in the face of climate change. 

“There’s also a flow-on effect to our cotton communities, helping our regional communities and councils protect their water sources against low rainfall and drought.

“This research project will be practical and applied at the field level and at the end, it will go to the government with hard data to inform policy proposals.

“A robust legal framework will be established to support FPV installation. 

“By bringing together energy regulators, local, state, and federal policymakers, agricultural landholders and renewable energy developers, regulatory principles and conditions will be designed that are tailored to FPV projects with irrigators. 

“This regulatory model will enable transparent streamlined assessment and approval processes to foster FPV adoption across Australia.”

For more

Susan Maas
susan.maas@crdc.com.au
This article appears courtesy of the Cotton Research and Development Corporation (CRDC). It was published in the (Winter 2025) edition of CRDC’s Spotlight magazine: www.crdc.com.au/spotlight