Upgrading energy systems delivers cost savings for Wagga Wagga mixed-farming operation
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“Energy costs keep rising which keeps eroding our margins,” says new Bulls Run Manager Scott Hughes. “We need to explore our power options and select the most reliable and cost-effective solution, especially for our irrigation system.”
Scott is investigating the potential for swapping out his diesel pumps with electric to irrigate selected paddocks on his 7,497-hectare lamb and cropping operation near Wagga Wagga, NSW, to save energy as well as to use water more efficiently.
The Bulls Run is a renowned property in the Riverina region of New South Wales. The property consists of 7,497 hectares and is focused primarily on lamb production and cropping. With 40 kilometres of frontage to the Murrumbidgee River, it has the added advantage of being reliably watered throughout the year.
Bulls Run operates within the Paraway network of producers. It regularly purchases replacement ewes from Paraway sheep stations, and lucerne, wheat, corn, oats and barley are sold to other Paraway properties. Bulls Run boasts an historic homestead and woolshed, as well as a number of comfortable staff houses. The property has well-developed infrastructure, with multiple yards and woolsheds, brand-new silos and eight centre pivot irrigation systems responsible for much of the energy consumed on the farm.
Scott has reviewed the farm’s energy baseline and examined ways of saving energy with the overall goal of improving profitability by bringing down the cost of production.
Bulls Run energy profile
Table 1: Bulls Run energy breakdown
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The farm’s largest energy expense is the operation of the irrigation systems including bore and river pumps as well as eight centre pivot irrigators, followed by the tractor fleet, used mainly for various cropping tasks.
Table 2: Bulls Run's energy breakdown by end-use purpose
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Figure 1: Bulls Run energy use by type and purpose. With over 80 percent of the energy used for pumping water for irrigation it’s easily the greatest focus for savings.
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Cost reduction opportunities
How energy fits into the equation
The majority of energy used on Bulls Run is found in pumping for irrigation. Energy is also used in the homestead, including for domestic water heating and cooling.
$29,000 in possible energy savings
Scott has identified and quantified several energy cost savings opportunities. These are shown in Table 3 (below), where blue shading indicates opportunities that were nominated by Bulls Run management as the priority areas to investigate.
Table 3: Full list of opportunities with priority opportunities highlighted
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It’s all about pumping
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“We will keep innovating when it comes to reducing irrigation cost and optimising yield.” |
The vast bulk of energy use and cost on the farm is for irrigation (~88% or about $500k) which means that even small efficiency gains can result in big savings and should be the primary focus area for operational improvement (compared to making a relatively minor impact to other areas such as vehicles and the household).
When evaluating pumping, there are a number of areas that Scott recommends to implement cost savings, based on current irrigation practises. These may include:
- Operating & Maintenance (O&M) improvements to identify and address poor performance early on;
- conversion from diesel to electric motors where deemed cost-effective; and
- use of variable speed drives for pumps with varying flow requirements.
Information papers available via the AgInnovators website provide more details on these and other opportunities:
Many operational costs are often locked in, based on the type of irrigation system. For example, the use of pivots will carry higher energy costs but, ideally, this additional cost is countered with reduced water pumping requirements so that the farmer comes out cost-neutral. NSW DPI is conducting further assessments to ascertain whether this is the case.
Moisture probes to optimise irrigation control and save money
Moisture probes can provide substantial benefits to farms with potential to optimise irrigation. If data from moisture probes allows a farmer to reduce irrigation watering by 3% (or about 6 days in 6 months), this could deliver savings of around $18,000 for farms comparable to Bulls Run in size.
It is probably worth a look if you suspect over-watering is a possibility at your property. Moisture probes can be drilled into those paddocks where overwatering is more likely – river flats and undulating country would be a good place to start. These sensors, installed in half-meter-long PVC pipes and placed into drilled holes (see Figure 2 ), can provide data on soil moisture and salinity at multiple depths; the sensors are topped with flexible antennas and are resilient to run-overs by tractors.
Figure 2: Example of a moisture and salinity probe that can be used to monitor field conditions (Sentek, 2010)
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Combined with more accurate weather forecasts, moisture probes can help farmers decide where and when to use their irrigation systems. A range of options exist, from buying these systems outright to a pseudo lease-style arrangement for a full off-farm monitoring system.
Figure 3: Soil moisture graph for a dryland wheat property in South Australia. Case studies for farms in South Australia have shown the value of these probes in helping make irrigation, application, harvesting and sowing decisions.
AgByte, 2013
Link to case studies for farms in South Australia.
The installation of moisture probes and back-to-base monitoring can enable growers and irrigators to track seasonal data and make split-second decisions that may affect the daily task sheet for their farmhands as well as the health of their crop and the cost of moving water around their property. The farmer can now receive soil moisture analysis data on a smart phone, tablet or PC in real time, facilitating water and energy use decisions that will deliver perhaps as much as 5% in savings.
Optimise tractor maintenance, set-up and operation and save 4%
Optimal tractor set-up and maintenance can deliver between 2 and 20 percent fuel savings depending on current practices.
Given that Scott already has good tractor set-up but is not always in control of the tractors’ use and maintenance – that is the domain of the operators – he estimates more conservative savings of 4% from adaptive driving and from paying more attention to tyre pressures
Figure 4: Tractor set includes front and rear ‘suitcases’, duals or singles, radials or cross-ply, rated horsepower for the task, and correctly selected and connected implements.
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A 4% improvement in fuel efficiency could add up to $2,000 in yearly cost savings for Bulls Run.
A first step that can improve efficiency immediately is for Scott to ensure his tractor and header fleet undergoes any outstanding maintenance and repairs that may be required.
The next step consists of analysing tyre pressures, ballast points and wheel slippage to assess whether any optimisations can be made. Research by NSW Farmers and groups such as Efficient20 suggests that optimising non-optimised machines can reduce their fuel use by 20%. More information on these options is available through the following information papers:
- Energy efficiency and farm vehicles – adaptive driving
- Tractor ballasting
- Monitoring wheel slip to achieve fuel efficiency
- Tyre pressure and fuel efficiency
- Efficient20 Advisor’s Brochure
Figure 5: Possible fuel savings from tractor efficiency measures.
Efficient20, UK, 2013
Additional measures include ensuring the correct gear is being selected for each operation. The ‘Gear Up, Throttle Down’ (GUTD) practice can result in significant fuel savings if used when the machine is significantly underloaded. More information is available in the following paper:
Electricity discounts are becoming more generous as demand softens in eastern Australia
In eastern Australia, electricity demand continues to wane. With more than one million installations in Australia, solar PV is having a major impact on demand (over 1,000MW installed), but the number of installations is slowly decreasing due to removal of subsidies. The economy is flat and a number of industries have gone offshore to secure cheaper energy (and labour). Those still in Australia have invested in energy efficiency, which is also contributing to a reduction in overall demand.
The NSW market outlook is flat but prices will begin to climb again over the medium term, says energy procurement specialist David West from energy management consultancy Energetics, which last year negotiated more than 1 billion dollars in electricity contracts. “Generators are selling energy for less than it costs to generate, so expect this trend to change soon. Prices will begin to rise,” he says.
Scott contacted his electricity retailer and has increased his discount from 14 to 25 %, saving an additional $1,800 per year. Talk about a quick win!
It’s a very good time in early 2015 for energy users to be in the market for NSW electricity contracts, or at least asking for a discount if currently on a franchise tariff agreement.
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Discount upgraded from 19 to 25% after one phone call |
Figure 6: Note the discount on this bill (general example). If you don’t have a discount of at least 15-20%, contact NSW Farmers and enquire about applying for a discount on your electricity.
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Time of use (ToU) may be a quick win – meters and management deliver around $5,000 a year in savings
Previously, all electricity consumed at Bulls Run was measured using old meters and didn’t capture any off-peak power. But recently, Scott contracted an electrician and changed all the meters for his electric-powered pumps (around 10 meters) to smart ones. He also contacted his electricity retailer and arranged to have the consumptions measured by these meters billed on a time-of-use (ToU) tariff. This has allowed Scott to take advantage of cheaper rates for power during off-peak times. However, although Scott’s river pumps and other loads are now on ToU tariffs, this equipment is still not controlled by timers. As Scott puts it, this is because “when you need the water, you need the water!”
ToU meters can deliver savings when:
- you are charged a higher rate for peak than for off-peak power – check your bill; if it’s not currently the way you are billed, your retailer can offer you this tariff in the future (some have been offered smart meters as their tariffs have been switched to ToU);
- you can reduce your pumping time during peak and shoulder periods (normally mid-morning to early evening) – again, check your bills or your retailer’s website.
- Otherwise, you are not likely to achieve any cost savings by installing ToU meters on your property.
Nonetheless, Scott estimates that his recent changeover to ToU tariffs (even with no schedule control on equipment) has likely amounted to around $5,000 or more in savings by enabling him to access lower-cost power at off-peak times.
Although they can’t be applied to all equipment, Scott is still interested in investigating the viability of timers, to enable even greater savings from ToU tariffs.
Outcomes
Optimising the irrigation set-up using scientific measurement will inform this property’s operations for many years to come, especially when irrigating during winter. When you add swapping out selected diesel pumps with electric motors and electricity discounts, Bulls Run can expect to save around $20,000 a year for a very small investment, as well as only using the water they need to produce the desired yield.
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The next time an irrigator is used, it will be done so with knowledge of the exact levels of moisture in the soil. Knowing when optimum levels are reached will then allow turning the water off at the ideal time. |
Figure 7: Expected energy savings from continuing implementation of projects (including solar PV).
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Planning for a long-term future in corporate farming
Scott will continue to explore energy-efficiency and energy-productivity options that support his goals of maximising yields and achieving flexibility in his crop choice and lambing operation.
Over the short term, in addition to accessing a bigger electricity discount from his supplier, Scott will focus on tractor set-up and tyre pressures to optimise wheel slip and minimise diesel use.
In the medium term, he will initiate the use of probes to better understand his soil moisture profiles and the impact of irrigation on yields in order to minimise overwatering.
Long-term opportunities include the use of variable watering irrigators informed by moisture monitoring, which will further optimise his irrigation system, delivering consistently higher yields, especially over undulating country.
The NSW Farmers’ Energy Innovation Team will monitor the development of variable irrigators and help Scott to engage Charles Sturt University with the soil moisture back-to-base monitoring system.