Grid Charging

Grid connection costs, use of system charges, benefits and credits and underwriting are an ever important part of project development and operation.  Charging arrangements for transmission and distribution can be complex to understand and forecast.

Xero Energy has extensive experience providing expert advice and estimates covering:


  • Distribution connection and reinforcement costs
  • Transmission connection charges and one off charges
  • Underwriting and security requirements


  • Use of system charges (TNUoS, GDUoS)
  • Balancing charges (BSUoS)
  • Line loss factors

Transmission Network Use of System Charges (TNUoS) are levied against projects that directly connect at transmission level or are connected at distribution and large enough to be liable. This charge is zonal (or locational) in nature and can vary significantly depending on in which zone the project connects to the transmission network.

TNUoS Tariffs are updated annually and so vary throughout the lifetime of a project. This charge can have a significant impact on the economics of a project and hence there is significant value in being able to forecast TNUoS charges throughout a project lifetime.

Xero Energy has developed a model to forecast TNUoS charges out to 2040. Our model had been validated against National Grid’s own TNUoS model and takes a wide range of forecast input variables including generation and demand trends, system reinforcements, transmission revenue recovery and regulatory impacts to forecast long term trends reflective of socio-economic change, environmental perspectives, technology improvements and the political arena.

Our first report in 2015 was well received by project developers, financiers, and owners large and small. An updated version for 2016 is now available and is a critical element in understanding future project economics, supporting investment decisions and in choosing strategic business direction.