A snapshot of total energy use and two main production systems contributing to energy consumption onsite includes:
|Annual Energy Use
A recent energy audit showed how improving the current systems can lead to energy and cost savings. The audit recommended the following measures:
- Reduce time of use of steam generator showing a reduction of 19,602kW per annum and cost reductions of $1,789 per annum.
- Install a 30kW solar PV, reducing electricity consumption by 44,170kW per annum and costs by $16,145, including demand charges. This system would have a payback period of 2.6 years.
- Identifying causes of peak demand – looking for opportunities to shift load such as staggering machine start-ups, which could reduce demand by nearly 12kW, saving $2,575 per year.
- Change tank filling to off-peak, further reducing demand, saving over 6kW and $2,813 per annum.
- Quick wins such as turning off unused computer screens and workshop lighting when not in use, saving 4,207kWh and $366 per annum.
Table 1. Costs and savings from audit recommendations.
||Reduce Time of Use of Steam Generator
||Install 30kW Solar PV
||Move tank filling to off-peak
||Identify Peak Demand Causes
||Turning Off Lights and Appliances
|Energy Savings (kWh)
|Demand Savings (kVA)
|Cost Savings ($)
|Emission Reductions (t CO2-e)
|Capital Cost ($)
Water is supplied to the main tank from two bores, automated to fill when the water level drops below a predetermined level. Water is then pumped to the nursery using four multi-stage variable speed pumps. Given the potential savings from shifting the tank-fill pumping to off-peak times, a real-time energy meter was installed onsite, capturing the main pumping circuit that supplies the header tank. The device has an average installation cost of $1,000 and will allow the business to understand their energy consumption, being able to find further demand reductions onsite. Read more about HERE.
From the energy audit recommendations, the grower proceeded with the implementation of the 30kW solar PV system. The savings made have been measured in a Measurement and Verification (M&V) process, as outlined in Table 2.
Table 2. Estimated and Actual energy and cost savings.
|Energy Savings including exports (kWh)
|Cost Savings including exports revenue and demand charges ($)
The lower cost savings measured compared to those estimated from the audit recommendation can be explained by higher peak demand during the measurement period than estimated in the audit report. If the farm were to shift more of their daily electricity consumption to the middle of the day, the savings would increase.
From the solar generation, 79% or 41,763 kWh are being used onsite valued at $2,394, and 11,450 kWh are being exported to the grid with a revenue of $687. Considering that 125,654 kWh – 75% of the total energy use onsite – are being imported from the grid at a cost of $6,302, there are potential savings from shifting consumption into the solar generation period. The total power balance of the farm, including solar exports and the energy cost distribution, are shown in the following figures.
From the implementation of recommendations in the audit, the farm has reduced energy consumption by 31% and costs by 30%, including feed-in revenue, with Carbon emission savings of 43.1 t/CO2-e per year.
Table 3. Pre and post implementation energy and cost improvements.
|Energy Consumption (kWh)
An Energy Savers field day was at HQ Plantations with presentations on water, energy efficiency and a technology showcase highlighting efficient pumps, lightweight solar PV and new financing opportunities. Click HERE for more information.
An energy audit is a good investment.
An energy audit is a great way for a business to cut costs and boost productivity. Find out about what’s involved in an energy audit HERE and subscribe to our bi-monthly energy e-news HERE.
If you have any energy efficiency related questions for the team, get in touch at email@example.com.
The Energy Savers Plus Extension Program is delivered by the Queensland Farmers Federation with support and funding from the Queensland Department of Energy and Public Works.