Energy Savers
Sunshine Coast

Sunshine Coast Nursery

Proposed
48
Proposed Energy Savings
Industry
Nursery and Garden
Location
Sunshine Coast
Solution
LED lighting, solar systems, and demand reduction

Farm Profile

A large Sunshine Coast nursery has the potential to reduce energy consumption and costs from findings in a recent energy audit. The site has increased production using a newly constructed tissue propagation lab aimed at meeting demand from commercial avocado plantations.

The nursery located on the Sunshine Coast consumes 328,895 kWh costing $63,314 to produce around 322,840 plants per annum on a 20.5ha site. The growing areas are a mixture of outdoor (2.9 ha), shade-houses (2.6 ha), polytunnels (0.06 ha), climate-controlled greenhouses (0.35 ha), and several dark rooms for clonal avocado rootstock production. The tissue culture and greenhouses consume 120,935kWh at a cost of $28,421.

The audit found the farm could reduce energy consumption across the whole site by.

  • Load shifting at no cost
  • Replacing fluorescent lighting with new LEDs
  • Installation of a new split system air conditioner
  • Installation of a 78-kW solar PV system for the tissue culture facility
  • Installation of two 30-kW solar PV system
Recommendation Energy Savings (kWh) Cost Savings ($) Payback Period (Years)
1) Load Shifting (demand savings) 17.5kW 350 Immediate
2) New LED lighting

 

1,982 726 1.2
3) Replace old air conditioner

 

4,569 1,076 1.8
4) Install a 78kW solar PV

 

65,547 13,553 7.2
Two 30kW solar PV systems (Combined)

 

93,714 19,160 3.65 (averaged)

 

Implementing options one to four has the potential to reduce energy consumption by 72,098 kWh and $15,355 per year, for the tissue lab and greenhouse area.

While installing two 30-kW solar PV systems on the separate NMIs could reduce energy and costs by 93,714 kWh and $19,160 per year.

Overall a 48 per cent reduction in electricity consumption across the whole site could be achieved with savings of 162,812 kWh and $34,515 per year. This would be subject to allowable export when connected to the grid, highlighting the importance of good design and expert advice.

The grow rooms were constructed to allow increased production at the nursery. While this has occurred, energy use has also increased to 143,326 kWh per year. The increased use may lead to the nursery becoming a large user at another meter, resulting in demand charges on two meters and increased costs. Further, it is expected that energy consumption will increase a further 22 per cent at the tissue culture lab as the nursery continues to ramp up production.

  Pre-Audit (kWh) Post-Audit (kWh) Pre-Audit Cost ($) Post Audit Cost ($)
Whole of Site (Three meters) 328,895 166,083 63,314 44,154
Tissue Lab and Grow Houses

(included in the above)

120,935 48,837 28,421 13,066
With expected 22% increase in production   59,581    

 

The audit has considered the increase in production and expected energy consumption. With installation of recommendations in the audit the Tissue Lab and Grow Houses can cut costs and keep below 100,000kWh now and into the future.

If all audit recommendations are implemented new benchmarks will be achieved and a reduction in kWh and cost per unit produced will be realised.

Pre and Post Audit Benchmarks:

  Pre-Audit 328,895kWh Post-Audit 166,083kWh Percentage Reduction (%)
Plants Produced 322,840
kWh per unit produced 1.03 .51 50.49
kWh cost per unit 0.21 0.14 33.33