TNUoS: What’s cappening?

Transmission Network Use of System (TNUoS) charges are a hot topic in the energy industry. Charges have been increasing and are forecast to continue to increase over the coming years, potentially reaching levels which could prevent the deployment of renewable power essential for achieving Net Zero. This is not a new issue. The industry has been grappling with TNUoS charges for a while now and a number of changes have been proposed or implemented over the past few years. However, it is only in the past few months the regulator, Ofgem, has considered that something needs to be done, particularly surrounding generator TNUoS charges, and has stepped in with a plan to limit them. In this blog we take a look at what TNUoS is, what the key issues facing generators are, and what is now being proposed to address them via a new code modification, CMP444. Given the importance of this change, we have upgraded our long-term TNUoS forecasting capability to quantify its potential impacts.