On 31 December 2025, The Infrastructure Planning (Onshore Wind and Solar Generation) Order 2025 came into force. Consequently, the threshold at which solar developments are classed as Nationally Significant Infrastructure Projects (NSIPs) in England increased from 50MW to 100MW. In practical terms, this means many larger solar schemes will now be consented through local planning authorities rather than via the development consent order process.
This shift has been a long time coming. The 50MW threshold, set back in 2008, increasingly felt disconnected from today’s technology and project economics. Panels are more efficient, layouts have evolved, grid constraints are different. A 50MW scheme today doesn’t carry the same scale or impact it might once have implied.
In increasing the threshold, the Government acknowledged that the 50MW threshold resulted in constraining the market for ‘mid-sized’ projects (being projects between 50-100MW). Projects in the 50–100MW range often found themselves in an awkward middle ground: large enough to trigger the cost and complexity of the NSIP regime, but not necessarily large or complex enough to justify it commercially.
Raising the NSIP threshold to 100MW is clearly intended to ease that tension. More projects can now remain within the local planning regime, at least in principle reducing time, expense, and procedural weight. Whether local planning authorities always have the appetite or capacity to deal with larger schemes is another question.
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