The UK’s network will need to adapt as outdated generation is left behind and power gets smarter, says WSP PB’s Katherine Jackson.
Over the past 15 years, the UK transmission and distribution infrastructure has had to change much faster than some expected and its future can be difficult to predict.
Our network was designed to transmit electricity generated from large thermal power plants down to consumers through the distribution network. But the UK’s decarbonisation plans have brought new innovations such as low-carbon technologies and small renewable generation, which have changed the size and type of generation.
This change can also be seen at the transmission level. New transmission infrastructure is required due to the closure of coal-fired power plants and the increase in large offshore wind farms connected to parts of the transmission system to which large generators have not previously been connected.
There is also a greater proportion of intermittent generation that has made it more challenging to balance supply and demand in real time.
As we move towards electric vehicles and the electrification of heat to support our 2050 greenhouse gas emission reduction targets, network companies need to invest to replace their ageing assets. Electricity networks will need to be able to cope efficiently with these changes.
Planning for change
Fortunately, Ofgem realised more than 10 years ago that network owners and operators would need to innovate more to develop crucial knowledge and expertise and to share it across the industry. To achieve this, they have used various regulatory incentives, with the current one being the Network Innovation Stimulus to support low-carbon projects.
“There has already been significant change, with several areas of innovation having already become business as usual”
There has also been work carried out under the Smart Grid Forum, which was created by the Department of Energy and Climate Change and Ofgem to support the UK’s transition to an affordable low-carbon system. This included a detailed assessment of the electricity system of 2030, with particular focus on the design and operation of the distribution networks, including new technologies (the DS2030 studies).
It is evident that there has already been significant change, with several areas of innovation having already become business as usual, including active management of distributed generation, the use of real-time thermal ratings and flexible industrial and commercial demand.
Distribution networks are becoming smarter, with greater use of control and communications. Other innovations such as battery storage and flexible domestic demand require further development both in terms of implementation and their commercial frameworks.
The DS2030 studies showed that smart solutions using new technologies can postpone the need to replace or upgrade, but in most cases this conventional reinforcement will still be required at a later date. The studies also highlighted that a strategic approach to making distribution networks smarter offers best value.
On the transmission system work has already been done to support the increase in north-to-south power flows from additional wind generation in Scotland down to the rising demand in the south of the UK, while other projects are ongoing such as the Western HVDC link (high-voltage direct-current).
Transmission reinforcement will also be required in the future to connect much larger new nuclear plants, and National Grid is currently consulting on how to connect Moorside nuclear power station in Cumbria to the electricity transmission system.
We can expect further changes in the transmission infrastructure with the next National Grid Electricity 10-year statement expected this month, as well as within the next Network Options Assessment Report due at the end of January 2017.
Katherine Jackson is energy technical director at WSP PB