Our greatest emissions are in our Scope 1 emissions from power generation at our thermal and geothermal operations and through fuel use in our vehicles. We monitor our direct emissions and other discharges to air in line with resource consents and reporting requirements under the Emissions Trading Scheme. Accurate monitoring enables us to track progress against targets and ensure transparency in reporting. In 2018 we are voluntarily reporting our Scope 1, 2 and 3 emissions in line with the Greenhouse Gas Protocol 2004, and we have rebased our Scope 1 emissions to align across the three scopes. We have also applied the operational control consolidation approach, which allows us to focus on those emissions sources that we have control over and have the ability to change.
This year our emissions from electricity generation increased by 4% on the prior year as a result of low hydro inflows in our catchment over summer and autumn, which required us to run our thermal power stations more to maintain electricity supply. More detail can be found in our Greenhouse Gas Inventory Report