CO2MultiStore carbon low-carbon heat Oil and Gas Authority Cost Reduction Delivering CCS Energy Bill 2015 climate change CCS Costs CCS Clusters £85/MWh CCS Lessons Learned infrastructure Spending Review 2015 energy intensive industries Industrial CCS fifth carbon budget cost-competitive CCS Clean Growth Strategy CCUS Cost Challenge Taskforce oil and gas CCS Strategy CCSA Cost Challenge Taskforce UNFCCC CCUS industrial strategy COP21 CO2-EOR Joint Industry Project energy demand Phase 2 CCS competition regional growth SCCS hydrogen Paris Agreement CCS North Sea CCS Technology