Industrial decarbonisation can be supported by green hydrogen as a fuel and feedstock, but its cost remains too high to compete with natural gas. In this study, the achievement of cost competitiveness for green hydrogen is examined through a combination of internal interventions, including the reduction of electrolysis costs via waste heat sales to district heating networks and the use of curtailed wind, alongside external interventions such as market-based policies and sustainability-linked bonds. A novel temporal market penetration assessment model has been developed and applied to evaluate the impact of these interventions, both individually and in combination, on achieving cost parity. The methodology has been implemented in a UK case study to assess these dynamics within the energy landscape and policy framework. The findings indicate that cost reductions of 17.5 % can be achieved through hydrogen from curtailed wind, while waste heat utilisation contributes a 24.7 % reduction. Existing policy measures are found to have the potential to lower costs by 39 %. A total cost reduction of 78 % is observed when interventions are blended, with green hydrogen from curtailed wind projected to reach cost parity with natural gas by the mid-2030s under high natural gas price scenarios. The feasibility of blended interventions in facilitating the industrial adoption of green hydrogen is thereby demonstrated.