An update on NESO’s recent announcement on TNUoS Tariffs and what this means for Energy Consultants and Businesses

Last week, the National Energy System Operator (NESO) released its latest Five-Year View on Transmission Network Use of System (TNUoS) charges — and the message is clear: major cost increases are coming.

TNUoS charges, which help fund the UK’s electricity transmission network, are set to rise sharply from 2026/27, with further hikes expected through to 2030/31. For large energy users, this could significantly impact operating budgets.

For energy consultants and businesses alike, it’s now crucial to understand what’s driving these changes — and to start planning to manage the impact. Here at EDF, we’ve tailored our solutions to the current market uncertainty, and we have different options to support our energy consultants and businesses.

NESO has published its latest Five‑Year View on TNUoS tariffs, which reveals significant expected increases:

• TNUoS ‘Allowed Revenue’ is set to increase from £5.1bn in 2025/26 to £8.9bn in 2026/27, with further rises in later years
• Most impactful to customer bills is the change in ‘TNUoS Demand Residual’ which is set to recover £3.8bn in 2025/26 and increasing to £7.5bn in 2026/27, with further rises in later years.
• This TNUoS Demand Residual (TDR) tariff is equivalent to c. £15.7/MWh on customer bills in 2025/26 and increasing to c. £30.5/MWh in 2026/27, with further rises in later years.
• Other changes were made by NESO to the locational element of TNUoS tariffs, although the above TDR tariff represents the vast majority of the TNUoS charge for most customers. 

These changes are largely driven by:

• The transition to the RIIO‑3 price control period with new revenue allowances.
• Significant grid reinforcement investments to accommodate renewable generation in remote locations.
• Updates to NESO’s transport models affecting locational tariff calculations.

NESO points out that major market reforms under the Review of Electricity Market Arrangements (REMA) won’t be fully in place until around 2029. Until then, businesses and energy consultants should focus on understanding how these upcoming tariffs will affect them based on their specific energy use.

We expect another update from NESO in November, and we expect the final rates to be published in January. 

So, what does this mean for Energy Consultants and Businesses?

More Complex Cost Forecasting

TNUoS charges are becoming less predictable and are expected to rise significantly, creating new challenges for energy consultants. To manage this, consultants need to collaborate closely with EDF to develop more accurate forecasting models that can predict their clients’ exposure to these charges. It’s also essential to monitor regional locational changes carefully. Additionally, consultants must consider the impact of evolving methodologies used by NESO, which influence how these costs are allocated across different users.

Increased Client Costs & Budgeting Pressure

For large electricity consumers like manufacturers, data centres, and public infrastructure, TNUoS costs can make up a significant part of their electricity bills. With sharp increases expected—potentially nearly doubling by 2026/27—energy consultants will need to assist clients in revisiting their energy budgets, forecasts, and procurement strategies. Additionally, energy consultants should prepare scenario models that account for different TNUoS pricing assumptions to help clients better manage the financial impact.

Strategic Opportunities

EDF can also support our customers and business partners by offering tailored net zero solutions designed to help manage rising network charges and reduce overall energy costs. This includes advising on site capacity reviews to ensure businesses are not paying for more capacity than they need, or missing opportunities to optimise their energy use. We also provide battery storage solutions that can help businesses shift their energy usage to times when electricity is cheaper, or even avoid peak charges altogether. In addition, EDF offers onsite generation options, such as solar PV or combined heat and power (CHP) systems, enabling businesses to generate their own electricity, reduce reliance on the grid, and cut carbon emissions. By combining these solutions with expert guidance, EDF can help businesses build resilience against future cost increases and move confidently towards a more sustainable, low-carbon future.

These changes also present opportunities for consultants to provide strategic value to their clients. The majority of TNUoS cost is determined by site capacity, so ensuring these are appropriate is an efficient way to manage TNUoS costs. On smaller elements of TNUoS charging, energy consultants can help clients, by supporting Demand-Side Management (DSM), shifting their energy use away from peak times or adopting load-shifting technologies to reduce cost exposure. 

Risk Management Is Now Essential

NESO’s update highlights ongoing tariff volatility and regulatory uncertainty, with major reforms under REMA still several years away. As a result, energy consultants need to educate their clients about the risks associated with policy changes and ensure these risks are factored into procurement and hedging strategies. It may also be necessary to renegotiate or structure long-term contracts to account for these uncertainties and protect clients from unexpected cost fluctuations.

Energy consultants and businesses who stay ahead of regulatory and pricing changes, deliver tailored, location-specific advice, and offer solutions such as flexibility, embedded generation, or tariff avoidance will be best positioned to stand out in the market. By adapting to these evolving challenges, they can help protect their clients from rising grid costs and secure a competitive advantage in the industry.

At EDF Business Solutions, we’re committed to helping our energy consultants and businesses stay informed and ahead of the curve, with our team of experts providing the insight and support needed to navigate complex market changes like this. We work with our energy consultants to understand their unique circumstances, offering tailored solutions and market intelligence to help them manage their exposure to rising network costs.

If you have any questions regarding TNUoS or would like to know the different options and support available, please reach out to your account manager.