ReFlex – Revolution of Flexibility Markets through Reactive Power Flexibility

Summary

PSC’s mission is to provide the expertise and solutions needed to empower utilities and energy companies to innovate and thrive in a rapidly changing industry.  In delivering this mission PSC have delivered a number of innovation projects funded under the Ofgem Network Innovation Allowance (NIA) mechanism.  Following on from the success of one of those projects (Virtual Statcom) PSC worked in partnership with Western Power Distribution (WPD) to develop a project for submission to the Ofgem 2021 Network Innovation Competition (NIC).  This project called ReFlex – Revolution of Flexibility Markets through Reactive Power Flexibility – aims to demonstrate the huge potential for distribution-connected customers to be rewarded for reactive power flexibility whilst enabling more efficient and economic operation of the distribution networks. Unfortunately, the ReFlex project was not selected for the NIC 2021. However, both PSC and WPD see benefits to the distribution networks of reactive power as a flexibility service and are continuing to develop project ideas to further the case for a ReFlex network trial.

Project Background

Significant growth in the number of Low Carbon Technologies (LCTs) connected to distribution networks is expected as the UK moves toward net-zero carbon 2050.  This is both in terms of renewable generation and new loads such as the electrification of transport and domestic heating.

This increased LCT penetration on networks causes constraints such as increased equipment loading, increased system losses and breaching system voltage limits.  The traditional network design approach to overcome these constraints is to reinforce the network through additional network infrastructure.  Can a DNO facilitate high penetration of LCTs in distribution networks by utilising existing network assets using an innovative flexible power system solution?

In recent years there have been several projects demonstrating and developing the potential for distribution-connected customers to operate in flexibility markets through the increase and reduction in their output.  However, all of those projects have focussed on altering the active power output of devices to overcome constraints on the distribution network.  There is a growing need for more flexible reactive power to support the operation of distribution networks.  It is recognised that the growth in LCTs must accelerate to achieve Net Zero and harnessing the collective reactive power capability of these LCTs has huge benefits that haven’t yet been explored.

ReFlex aims to develop a first-of-its-kind reactive power flexibility market to provide this much-needed service to distribution networks to accelerate the growth in LCTs in a cost-effective manner to consumers.  A previous WPD NIA project (Virtual Statcom) highlighted the benefits of using reactive power support for network management.  The desktop study demonstrated that optimising reactive power from embedded distribution generators (DGs) has the potential to:

• Resolve or reduce network constraints without reducing generation or load.
• To increase the hosting capacity in distribution networks by 5-25%, estimated to be 2 GW across WPD’s network that could save £88 Million in reinforcement costs.
• Reduce distribution network losses by 3%, saving consumers £30 Million per annum and reducing greenhouse emissions by 0.16 million tonnes of CO₂ per annum.

ReFlex will build on the algorithms and learnings delivered by the Virtual Statcom project to develop an operational solution for a real system trial to enable distribution-connected customers to operate in a new way.  ReFlex will create a novel commercial arrangement to incentivise distribution-connected customers to offer reactive power as a service.  The operational solution and market mechanisms will be scalable across all DNO networks.

ReFlex will unlock the inherent reactive power capability of distribution-connected customers and create the ability for distribution networks to optimise this to efficiently alleviate constraints, reduce losses and increase the capacity for LCTs to connect without the need for costly distribution network reinforcement or curtailment of renewable generation.