MOSAIC is a strategic initiative by SPEN to address the growing complexity of the UK’s power system as it transitions to net zero. With the rise of inverter-based resources, declining system inertia, and increasing operational challenges, traditional tools and approaches are no longer sufficient.
The Centre will bridge the gap between research and operations, ensuring that new tools and methods are validated, aligned with business needs, and integrated into day-to-day practice.
By enabling earlier detection of system instabilities, supporting efficient planning, and reducing modelling costs, MOSAIC will deliver significant operational and financial benefits. It will also play a key role in building a future-ready workforce and strengthening the UK’s leadership in power system innovation.
Benefits
Constraint Cost Avoidance: The MOSAIC initiative is projected to deliver significant reductions in constraint costs by enabling earlier identification and mitigation of system instabilities that currently lead to the curtailment of renewable generation. The current CBA conservatively estimates annual savings of £1.2 million, based on the assumption that 1.5 GW of generation would be constrained for 8 hours per year, using a historically low balancing cost of £100/MWh. However, this estimate has been approached from multiple angles, all of which suggest that the actual value at stake is considerably higher. For instance, the sub-synchronous oscillation events in the Scottish network during Summer 2023, which persisted intermittently over a four-week period, highlighted the operational and financial risks posed by poorly damped inverter-based resources 1. Furthermore, NESO’s analysis of non-thermal constraint costs indicates that constraint-related expenditures are rising and expected to continue to rise sharply. These insights reinforce the strategic importance of MOSAIC in reducing constraint costs not only through direct operational improvements but also by de-risking future system configurations and supporting more efficient network planning.
Blackout Risk Reduction: MOSAIC is expected to play a critical role in reducing the risk of large-scale blackouts by enhancing the GB system’s ability to model, simulate, and mitigate complex dynamic phenomena associated with inverter-based resources.
The CBA estimates an annual benefit of £0.78 million from blackout risk avoidance for Scotland, based on a conservative scenario. This estimate is grounded in the methodology used by SSE, which values the economic impact of a major blackout at 0.7% of GDP. While such events are rare, their consequences are severe, as demonstrated by the April 2025 Iberian Peninsula blackout, which affected Spain, Portugal, and parts of France due to voltage instability and cascading failures. Similarly, the Texas power outages in 2021 resulted in widespread disruption, with estimated economic losses exceeding $100 billion (1.44% of GDP), highlighting the vulnerability of modern grids to extreme events.
MASIC’s EMT simulations and real-time co-simulation capabilities will enable more accurate black start planning, better system resilience assessments, and faster response strategies—substantially reducing the likelihood and impact of such catastrophic events. These capabilities are essential as the GB system becomes increasingly reliant on power electronic converters and low-inertia configurations.
The Cost-Benefit Analysis for MASIC demonstrates a compelling financial case for investment. Over a 25-year study period, a Net Present Value (NPV) of approximately £8.8 million is observed for Scotland alone, reflecting strong long-term value even under conservative assumptions. When the benefits are scaled to the GB system level, accounting for broader network exposure and constraint volumes, the total NPV exceeds £106 million, highlighting the national strategic relevance of MOSAIC.
