The UK energy industry is undergoing significant transformation, driven by the push toward decarbonisation, increased electrification, and the need for a more flexible grid. Alongside these structural changes, the way costs are allocated across the system is evolving.
Three key developments are reshaping how the industry operates and how costs are ultimately passed on to consumers: rising Transmission Network Use of System (TNUoS) charges, the introduction of the Nuclear Regulated Asset Base (RAB) levy, and Market-Wide Half Hourly Settlement (MHHS). You can read about TNUoS and MHHS here.
Nuclear Regulated Asset Base (RAB)
What?
Introduced as an additional levy in late 2025, this will be paid on the electricity bills of all consumers including domestic. Unlike other levies, RAB is mandatory and unavoidable and applies to every unit consumed. You can read our full explainer here.
Why?
The introduction of the RAB model marks a notable change in how large infrastructure projects are funded. Under this model, developers receive a regulated return on their investment during the construction phase, rather than waiting until the asset is operational. This lowers investment risk, making projects more attractive to institutional investors and this model has already been introduced for new nuclear projects such as Sizewell C.
Impact?
It has gradually been added to consumer invoices by all suppliers as an additional line item and as it’s a new charge can be added onto fixed price contracts. Reviewed quarterly by the LCCC, at the time of writing (June 2026) the government-set RAB rate is 0.4683p/kWh, though the rate seen on invoices may vary slightly by supplier depending on how they apply. Its impact will vary based on consumption. It is widely expected to fluctuate quarterly, with rates varying as nuclear construction progresses.
Issues?
While investors face lower risk through a reduction in financing costs, and theoretically the long-term cost of electricity generated by these assets, this also means that consumers begin contributing to project costs earlier through their energy bills, raising questions around affordability and risk-sharing.
The energy landscape is changing. If you want to understand what that means for your business, we’re here to help. Get in touch with the team today.
