6 February 2017 

It is now broadly accepted that we are shifting to a decentralised and flexible energy system, the question is how such a system will work in practice.

One point that is clear is that Distribution Network Operators (DNOs) will be at the frontline of the shift. The BEIS and Ofgem call for evidence on how our energy system could be more smart and flexible[1] states that; ‘in the immediate term, DNOs need to transition to Distribution System Operator (DSO) roles’. Operating a system necessarily requires monitoring, analysing and forecasting flows on that system.

To help address the challenge this presents, Regen has worked with Western Power Distribution (WPD) to develop bespoke local future energy scenarios to underpin their network planning. Using these, WPD has now published a report on the plans for their South Wales network.

WPD’s assessment of their South Wales network is available here: “Shaping Subtransmission to 2030”.

Regen’s report on scenarios for the growth of distributed generation and demand that underpin the assessment is available here: “Distributed generation and demand study - technology growth scenarios to 2030”.

In 2016, WPD completed a similar assessment of their South West licence area and studies on their two remaining licence areas, the East and West Midlands, are due for release later this year.

Growth of distributed generation

The reports show the scale of growth in distributed generation. There is now over 1.7 GW of generation connected to WPD’s South Wales network. This contrasts against an annual maximum demand of nearly 2.1 GW and minimum demand of less than 0.8 GW.

Current distributed generation capacity in WPD’s South Wales licence area (December 2016)

[1] A Smart, Flexible Energy System, November 2016

Looking forward, under all four scenarios considered, distributed generation will continue to grow placing further demands on the distribution network. Electric vehicle growth and storage are potentially disruptive factors.

Distributed generation capacity growth by scenario in the South Wales licence area

Implications for the network

WPD’s assessment of the demands on the South Wales network concludes that further reinforcement of the network is required under every scenario. Importantly some – but not all – of this reinforcement can be alleviated by using Active Network Management or other measures to curtail the output of distributed generation to prevent network overstressing.

The forecast reinforcement requirements are dominated by the connection of distributed generation. However, the electrification of transport and heating also has an impact. The studies are particularly sensitive to electric vehicle usage patterns, which may change dramatically as electric vehicles enter the mainstream. Further work is also needed to understand the potential impact of widespread take up of storage on the grid.

This work is beginning to provide an insight into how the shift to a distributed and flexible system will impact on distribution networks. If you would like to find out more about Regen’s work on these issues do get in contact with Joel Venn at jvenn@regensw.co.uk.

You can also find out more at Regen’s Smart Energy Marketplace event on 28 March in Exeter, at which Nigel Turvey from WPD will be speaking.

Author:  Joel Venn