Australia’s forests play a vital role supporting biodiverse, ecological production functions. These forests offer large carbon sinks drawing down 18,876Mt of carbon Australia wide, with an additional 144Mt stored in harvested wood products. The 2015–16 harvest produced 30.1 million cubic metres of log products from 1.95 million hectares of commercial plantations. On average one cubic metre of softwood logs contains sequestered carbon equivalent to 787 kilograms of CO2. Over a five-year period, the forestry sector contributed a net sequestration of carbon dioxide that offset 3.5 per cent of total human-induced greenhouse gas emissions in Australia.
Queensland’s HQ Plantations manages 343,000ha of land as the largest commercial forestry in the state. From 212,000ha of production area, 2.3 million m3 of wood is harvested, sequestering 1,810Mt of CO2 annually. One of the keys to HQ Plantations production cycle is an onsite 26-hectare nursery. Consisting of 7.6ha of production area, 2.9ha of shade structures and 4.7ha of full sun growing area, the nursery allows the growth of tube stock to replant cleared forest but uses significant energy for irrigation in the process.
An energy audit conducted as part of the Energy Savers Plus Program Extension showed on average 10,227,684 plants per annum were produced using 168,549 kWh at a cost of $16,698, excluding supply charges.. Contributing 43 per cent to total energy use, pumping onsite accounted for the highest single on farm 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.
A revisit to the nursery to install real-time energy meters enabled further discussion regarding opportunities to reduce demand charges, which accounts for 55 per cent of total electricity costs. Real time monitoring on the pump circuit will allow instant access to energy data and bring energy use to the forefront of the businesses’ mind encouraging behavioural change. Onsite, management changes in tank filling times and operation of simultaneous equipment could save the nursery $6,033 annually. An additional 4,207kWh and $366 can be saved through changes in behaviour, by switching off computers and lighting when not in use.
A further reduction in demand from the installation of a 30kW solar system would see 44,170 kWh and $16,145 in savings per year. Due to these large savings a payback period of 2.6 years would be seen making solar an attractive investment choice.
Onsite a reduction of, 48,377kWh and and 46.4 tonnes of C02 would result in cost savings of $22,544 per annum. A decrease in cost per unit of production could be achieved with increases in water and energy use efficiency.
HQ Plantations have long been a supporter of efficiency initiatives, hosting an Energy Savers workshop in February 2017 with presentations on water and energy efficiency, and a technology showcase highlighting efficient pumps, lightweight solar PV and new financing opportunities. Click HERE for more information.
The Energy Savers Plus Extension Program is delivered in by the Queensland Farmers Federation with support and funding from the Queensland Government.