Wilandra Smart Power Project
In 2019 we had an energy audit completed, that gave us detailed information about where we use energy, and opportunities to reduce power usage. That audit also gave us a desire to generate our own power and to reduce our reliance on traditional energy sources that have a significant carbon footprint.
At that time, our irrigation and dairy operations were using about 500,000kWh of energy a year. Since that time, we have implemented a number of initiatives to reduce power usage, such as replacing a 500m pipeline to reduce friction loss. A new bore pump was installed and those two improvements at that site were estimated to reduce power use by about 37% at that pumping site.
With the assistance of a grant from Agriculture Victoria’s Energy Investment Plan, and by partnering with Alternate Energy Innovations from Morwell (AEI) we’re implementing a major project in relation to power usage and alternate energy.
Renewable Farm Energy
Beginning in early 2021, we started a major project around energy efficiency and renewable energy with an automated energy management system to reduce the use of conventional power for our irrigation and dairy processes. At that stage, irrigation used about 71% of the power we were using.
Following the completion of irrigation and dairy energy audits funded by the Victorian government, we worked in conjunction with Alternate Energy Innovations (AEI) in Morwell to develop a Renewable Energy Action Plan (REAP).
This REAP was implemented with the assistance of AEI and includes:
installation of 200 kW of solar energy,
56kWH of batteries,
4, 5kW wind turbines,
the installation of AEI’s innovative and intelligent ‘AEI SmartBox’ systems, allowing for each irrigation and pumping component to be fully automated, controlled, and monitored, and
the AEI App which allows us to monitor and operate farm irrigation systems via smartphones, including the ability to schedule each centre pivot irrigator up to 3 days in advance.
To make best use of the renewable energy, other farm upgrades were required, such as upgrades to pivot controls and new pivot nozzle packs suited to the water flow rate, variable speed drives on pumps on bores and at the river, and a larger diameter, 1.2km pipe to reduce friction loss.
During 2022’s irrigation period the AEI system managed the operation of each irrigation/pumping component to achieve a utilisation of generated renewable energy (on a typical day) in excess of 90%, minimising grid usage to below 10%.
From a cost perspective, this resulted in an average total cost of irrigation energy in this period to
-3c/kWh, down from 24c/kWh in the equivalent period the year prior. The negative figure is achieved by feeding unused power into the grid.
In a full irrigation season, it’s expected that energy costs associated with irrigation will drop from approximately $80,000 to $100,000 per annum to around $15,000.
In addition to keeping energy bills low, other benefits include:
reducing our carbon footprint,
improving water use efficiency,
time savings during the irrigation season are about 15 hours a week,
less stress because we mainly irrigate during the day, when we can see what’s happening, rather than at night.
One of the most important things to think about with renewable energy is how to make use of the energy when it’s being generated, and this often means changing the time when you do things. This is referred to as load shifting. Another option is to store energy in batteries, but that is currently an expensive option.
For us, this means pumping water to the dam when we have the power to do so and generally not pumping water directly from bores to pivots when we want to irrigate.
Our process starts with a water height sensor in the dam. If we need more water in the dam, and we have just 10kW of power available, a pump at the river or at a bore starts delivering water to the dam – which has a storage function, similar to a battery. This automation saves considerable time on quad bikes – no one needs to drive to a pump to start it, and the VSDs mean that pumping begins with low levels of energy. This can be quite early in the morning, because we have solar panels that face east, north and west.
If the system knows that we need to irrigate, as soon as we have about 40kw of energy available near the dam (the site of 150kW of solar panels), a pump will start and deliver water to a pivot that automatically starts. 2, 37kW electric pumps have replaced a diesel pump that was used to pump water from the dam to pivots.
With the automation that’s now in place, if a pivot stops, for example because it’s stuck in a low, wet spot, the system detects that the pivot is stationary, and the water is turned off. This stops soil being over watered, and energy and water getting wasted.
We have solar panels that face east, north and west, to generate power for as much of the day as possible. The backs of the panels (described as bifacial panels) can also generate power, albeit a small percentage.
29kW of solar panels were mounted on the roof of the dairy in 2017. At that time, we switched from heating water during the night, to daytime heating with solar power. That is good most days, but not days that are very cloudy, when we use power from the grid.
Following an energy audit at the dairy, we have implemented several recommendations, including:
replacement of 2 old, oil ring vacuum pumps with a lobe vacuum pump – results in less power demand and no need to change the oil, much cleaner than previous vacuum pumps
Installed a new bore to get more water through a plate heat exchanger, to cool milk faster – very successful
Installed a CO2 heat pump hot water service – uses about one third of the power needed in a conventional hot water service. But, the unit has a high purchase price, required the addition of a circulation pump to get around water temperature stratification, and it may not be the best option in all dairies
Installed equipment to monitor temperatures and energy use around the dairy – very useful and successful
Still more work to do around the dairy to reduce power needed.