As the Deputy will be aware, under Project Ireland 2040 Ireland has committed to no longer purchasing diesel-only buses for the urban public bus fleet from July 2019. In preparation for both this immediate transition and the development of longer-term low-carbon bus procurement strategy, my Department, together with the National Transport Authority, Dublin Bus and Bus Éireann, is giving a great deal of consideration to these matters and has undertaken a comprehensive series of low-emission bus trials which are expected to conclude in the coming weeks.
Among the wide range of low-emission alternatives considered in these bus trials, was the testing of two compressed natural gas/biogas buses (single- and double-deck) using PEMS (Portable Emissions Measurements Systems) technology to assess emissions of CO2 and air pollutants such as NOx, amongst other test criteria. The Deputy rightly notes that compressed natural gas is a fossil fuel; accordingly, natural gas is only being considered as a pathway towards incorporating renewable biogas, or biomethane, into the transport fuel mix.
Biomethane use can significantly reduce pollutant emissions compared to diesel powered engines and can dramatically reduce carbon emissions by capturing energy from Ireland’s food and biological wastes and residues. The anaerobic digestion industry, which produces biomethane, is also a developing indigenous industry which could support a synergistic circular economy between the transport and agricultural sectors, while improving national fuel security and contributing towards 2030 sectoral targets under the Renewable Energy Directive.
In addition, the Clean Vehicles Directive, which legislates for public procurement at European level and will include within its scope the purchase of public urban buses, has undergone recent revision and is shortly expected to enter into force. Noting the role of the Directive in relation to bus fleet transition, the Deputy may be interested to learn that post-2025 over half of Ireland’s urban bus procurements will be required to deploy zero-emission fuels or technologies. Noting this requirement, the pending findings from the Low Emission Bus Trials, and additional research and market information, considerable deliberation is required to determine the future direction of bus procurement in the short and medium term. It would be premature to rule in favour or against any particular alternative fuel or technology in advance of these deliberations.