International Public Partnerships (INPP) has released its H1 2026 results with a headline development directly relevant to the British nuclear sector: the FTSE 250-listed infrastructure fund has confirmed an equity commitment of £254.3 million to the Sizewell C nuclear power station, to be deployed at approximately £50 million per year through to 2030. The portfolio NAV grew by 1.3% and dividend coverage strengthened to 1.3 times.
Sizewell C is the world’s first nuclear power station to be financed through the Regulated Asset Base (RAB) model — the same mechanism successfully applied to the Tideway project, London’s super-sewer. Under this framework, INPP receives regulated, inflation-linked returns from day one of its investment, regardless of actual power output or prevailing electricity market prices. This represents a paradigm shift in the financing of large-scale nuclear infrastructure: construction risk is partially ring-fenced from investors through specific contractual protections backed by the UK government.
The figures are compelling. The regulated equity return is set at 10.8% real during the construction and initial operational phase, with an annual cash yield of approximately 6%. The expected internal rate of return (IRR) sits between 11.5% and 13% — well above what INPP could achieve through share buybacks. The stake acquired amounts to approximately 3% of Sizewell C’s regulated company equity, alongside the UK government, EDF, Centrica, La Caisse, and the Nuclear Liabilities Fund.
Once operational, Sizewell C will generate around 3.2 GW of low-carbon electricity — enough to meet the needs of approximately six million homes and cover 7% of the UK’s projected electricity demand. The investment also extends the weighted average portfolio life of INPP by four years compared to a scenario without this commitment, bringing it to 38 years by 2030. A long-term horizon that reinforces the fund’s capacity to sustain its progressive dividend growth policy for at least 25 years.
On the political front, the Sizewell C project enjoys cross-party support in the UK Parliament, making it less vulnerable to changes in government than many other major infrastructure schemes. INPP’s regulated portfolio — which now includes a 3% stake in low-carbon energy assets, predominantly Sizewell C — accounts for 53% of total assets and delivered solid operational performance over the half-year. The fund manages more than 130 infrastructure assets globally.
The RAB model as applied to Sizewell C could become a blueprint for financing future nuclear plants across Europe and beyond. If the project meets its construction milestones, it will demonstrate that large nuclear facilities can be financed by private institutional investors with predictable returns and manageable risk. A litmus test the entire industry is watching closely, far beyond the borders of the United Kingdom.
