Powering irrigation with renewables

Written by Matt Schultz, Head of Energy Storage, Enel X Australia

Anyone in the business of water – its transportation, processing and consumption – is inextricably linked to the business of energy. As energy prices rise, irrigation companies and irrigation operators are being faced with increasing costs of moving water from supply infrastructure to on farm.

This is leading to companies and individuals investigating cheaper options for energy and moving away from traditional sources such as electricity and diesel to renewable sources such as solar power and batteries. Underpinning these changes is an awareness of climate change and the need to develop mitigation strategies that involve fewer emissions.

The best approach to integrating renewables will vary between organisations and even between sites. In this article, we showcase some of the measures that two irrigation companies and a water utility are taking to improve energy efficiency and reduce energy costs for themselves and their customers. 

Central Irrigation Trust (CIT), an irrigation cooperative in South Australia, recently partnered with Enel X to develop a network of 15 MWh of batteries across their pumping stations in Loxton, Chaffey, Cobdogla, Waikerie and Berri. This capacity is equivalent to around 1,500 home battery systems, and to our knowledge will be the largest installed single-customer battery in Australia when fully commissioned in May 2023.

For CIT, the best solution was to install batteries but not solar. This is because most of CIT’s pump sites, which are some of the largest energy consumers in the area, are in the middle of towns where there is no adjacent land to co-locate solar. Having a battery reduces network costs while earning revenue from the energy and ancillary markets.

The communities in the Riverland have very high solar penetration both from rooftop and nearby solar farms. Having large onsite batteries could improve the site’s resilience and have the potential to provide a platform to improve community resilience.

This project involved Enel X developing, funding and operating the batteries on CIT pumping sites, using their electrical infrastructure to access energy markets and reduce their electricity bills. This arrangement is a very low-risk way of CIT hedging their exposure to a volatile commodity, while supporting the broader community.

Renmark Irrigation Trust has plans to adopt a similar approach, adding an additional 2 MWh of batteries at their pumping site only 15 km away from the Chaffey site under the same business model. 

For organisations with available land or water bodies, installing land-based or floating solar systems can be the best option.

Gippsland Water is a water utility in South West Victoria, serving more than 69,000 properties with a substantial water treatment and wastewater treatment plant. Gippsland Water has a net zero carbon goal by 2030, and a 100 per cent renewable energy goal by 2025. Several solar plants have already been installed across the organisation, including a large 1,280 kW ground-based solar system at its largest site.

The organisation has recently installed a 350 kW floating solar system on one of its reservoirs. This system will not only produce clean energy, but will also reduce evaporation. This technology could be an important addition for the industry with three benefits: generating renewable energy, effective for space-constrained users, and improve water conservation. 

Where you live within Australia, and which network provides your power, has a big impact on your options to reduce costs. This is because networks have different tariff designs, which either make them more or less avoidable for different technologies.

One of our recent project proposals involves the construction of a large microgrid with a new HV network for a NSW irrigation customer under a hybrid purchase-power agreement (hPPA).

In this instance, the customer has ample land to develop solar, and the customer’s network has both high demand charges and high costs. Installing solar without batteries wouldn’t substantially reduce network costs, while having batteries without solar increases the risk of higher network costs when charging batteries. The best solution here is to have both solar and batteries, which in combination will reduce network costs substantially.

We are also proposing to combine a number of low voltage connections into one high voltage connection to both reduce costs and to maximise the scale of solar and battery plant. This new configuration will also make it easier for the microgrid to cover the reliability needs of the site in the case of a grid outage. 

When completed, we expect customer electricity costs to reduce by over 30 per cent and energy-related emissions by around 80 per cent. 

Most of us are familiar with the concepts of solar and batteries, which are in the news every other day, but renewable technology is very different to an irrigation company’s core business.

For solar, substantial differences can exist between product quality and the value of performance or product warranties by supplier. For batteries, the scope of uncertainty is much greater. The value of these assets is largely determined by three factors: the value of the energy markets they can access, the effectiveness of the ‘brains’ operating the battery, and the impact this operation has on the battery’s usable life.

By adopting renewables, irrigation companies can save money, improve the reliability of their power supply and reduce emissions. But given the industry’s complex demands, fluctuating energy market prices and evolving technology, the devil is in the detail: the best solution will vary depending on a company’s needs, assets, location, and customer demand profile.

This story originally featured in the Irrigation Australia Journal Summer 2022.