♦ Energy and greenhouse gases
Although IPL's energy use and GHG emissions increased with increased production, targeted global reductions in GHG emissions per tonne of product were achieved in 2017, with a 5 percent reduction per tonne of ammonia produced and a 9 percent reduction per tonne of nitric acid produced.
These targeted reductions were achieved due to the greater efficiencies at our new Waggaman Louisiana ammonia plant, and our investment in a new NOx abatement unit at Louisiana, Missouri. The efficiency targets at Waggaman which support these ongoing reductions were linked to executive remuneration through the Long Term Incentive plans, as explained in our Annual Report.
IPL used 61,972,212 gigajoules (GJ) of energy over the past year, 2,244,029 of which was purchased electricity. Approximately 80 percent of the electricity purchased was generated from non-renewable sources. Approximately 20 percent of the purchased electricity (indirect energy) was generated from renewable resources, mostly hydroelectric. Natural gas and diesel amounts used as raw materials and on-sold in our products have been included in our energy use figure. Approximately 1 percent of our direct energy is from CO2e-free sources, which includes electricity that is generated from heat captured during the manufacture of sulphuric acid.
Greenhouse gas emissions
In 2017 our recorded Scope 1 (direct) and 2 (indirect) absolute GHG emissions increased to 3,086,553 tonnes of carbon dioxide equivalent (CO2e). The total figure comprises 2,749,847 tonnes of Scope 1 (direct) emissions and 336,707 tonnes of Scope 2 (indirect) emissions. These increases were due to the new Waggaman, Louisiana plant, which increased IPL's ammonia production. Assurance was obtained over our Australian GHG emissions, energy consumption and production figures for the period 1 July 2016 to 30 June 2017. The third party issued an unqualified opinion over our reported emissions, energy production and energy consumption.
Improving our performance
In line with the sustainability strategy to ‘Use Less’ and ‘Care for the Environment’, our manufacturing plants continued to reduce both energy use and carbon emissions in 2017 through initiatives such as lighting reviews, plant energy optimization projects and other continuous improvements.
• At St Helens, Oregon, a project to convert the pneumatically controlled plant instrumentation to electronic instrumentation reduced annual electricity use at the site by 161,971 kWh.
• At Cheyenne, Wyoming, energy efficiency projects included pump and boiler optimisation and steam saving projects, which saved over 1,000,000 kWh of electricity and 73,000GJ of natural gas during 2017.
• The application of an internal coating to the reformer at Cheyenne, Wyoming will deliver further reductions in gas use during 2018.
• At Moranbah, Queensland, a project to preheat deaerator feedwater with process heat currently lost to the atmosphere is expected to save 196,000 GJ of natural gas, reduce GHG emissions by 10,000 tCO2e and save over $1,000,000.
• The installation of variable speed drives on cooling tower fans at Mt Isa, Queensland is expected to save 2,916,667 kWh of electricity, reduce emissions by 2,305 tCO2e and reduce costs by over $400,000.
We also quantified the Scope 3 emissions associated with our shipping for the second year in 2017, and offset these emissions with the purchase of voluntary carbon credits.