A recent study published in Science of the Total Environment evaluates the sustainability of power supply alternatives for offshore oil and gas platforms on the Norwegian Continental Shelf (NCS). Using a Multi-Criteria Decision Analysis (MCDA) framework, researchers compared three options: gas turbines, power from shore (PFS), and floating offshore wind farms (OWF). The findings highlight critical trade-offs between environmental, economic, and social factors, offering actionable insights for Norway’s decarbonisation goals.
Methodology: Balancing the Triple Bottom Line
The study employed the Triple Bottom Line (TBL) approach, assessing nine criteria across three dimensions:
- Environmental: Direct and indirect greenhouse gas (GHG) emissions, marine ecosystem impacts.
- Economic: Investment costs, carbon taxes, electricity expenses.
- Social: Worker safety, mainland energy security, and working conditions.
Stakeholder surveys revealed prioritisation weights: environmental (41%), economic (35%), and social (24%). Key criteria included Scope 1 emissions (15% weight), marine pollution (14%), and investment costs (12%).
Key Findings: Power from Shore Leads, but Challenges Remain
- Power from Shore (PFS):
- Strengths: Zero direct emissions, minimal worker safety risks, and the highest overall sustainability score.
- Challenges: Limited feasibility for remote platforms (average distance: 150 km) and potential strain on Norway’s onshore grid, which relies heavily on hydropower and wind.
- Gas Turbines:
- Strengths: Low upfront costs (450 million NOK vs. 1,979 million NOK for PFS) and operational reliability.
- Weaknesses: High emissions (205.9 kt CO₂/year) and poor worker safety due to noise, heat, and air pollution.
- Floating Offshore Wind (OWF):
- Strengths: Reduces emissions by 35% compared to gas turbines and avoids grid strain.
- Weaknesses: High costs (2,306 million NOK), ecological risks (marine habitat disruption), and reliance on backup gas turbines during low-wind periods.
Sensitivity Analysis: Economic Priorities Shift Rankings
The study’s sensitivity analysis revealed that gas turbines could outperform PFS if economic criteria dominate (e.g., doubled weighting). Conversely, PFS remains robust under environmental or social prioritisation. OWF consistently ranked last due to unresolved cost and ecological challenges.
Implications for Policy and Industry
- Regulatory Gaps: Norway’s current policies focus narrowly on emissions reduction. The study calls for holistic regulations addressing marine biodiversity and worker welfare.
- OWF Development: Floating wind technology requires subsidies and R&D to lower costs and mitigate environmental impacts. Projects like Hywind Tampen – Norway’s first floating wind farm – highlight potential but need scaling.
- Grid Upgrades: Expanding PFS necessitates investments in onshore infrastructure to prevent energy shortages for households and industries.
A Path Forward
The research underscores PFS as the most sustainable choice for near-shore platforms but emphasises the need for diversified solutions. For remote platforms, hybrid systems combining OWF and carbon capture technologies may bridge gaps. Future studies should address data limitations on marine ecosystem impacts and engage Indigenous and fishing communities affected by offshore developments.
By integrating MCDA into decision-making, Norway can balance its oil-dependent economy with climate commitments, setting a global benchmark for sustainable offshore energy.
Source
Assessing the sustainability of offshore platform power supply alternatives using Multi-Criteria Decision Analysis (MCDA): A case study of Norway. Science of the Total Environment, 973, 179053. 2025-03-10
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