National Grid measures real-time system inertia for the first time

For the first time ever, the National Grid has successfully measured and monitored continuous grid stability across an entire network, in a move that could reduce end-customer costs and carbon emissions in the UK.


Until now, grid operators used estimates to measure grid stability, otherwise known as system inertia, leaving measurements suspect to margin errors. These estimates were also used to set multi-year budgets for grid infrastructure investments, energy reserve services and dictated the trading outlooks between renewable and fossil fuel energy being used by the grid.

However, Project SIM has enabled the National Grid to gain real-time visibility of inertia on its systems, which are becoming increasing volatile as intermittent renewables generation claims a greater share of the UK’s energy mix.

Developed by energy engineering firm Reactive Technologies, Project SIM equips control room operators with real-time information that enables them to react to changes in demand and supply and take necessary actions to re-balance the system and reduce the risk of potential blackouts.

National Grid’s acting director of system operations Duncan Burt said: “National Grid is proud to be at the forefront of the energy revolution as we enable the uptake of renewable generation, and deliver value for our customers and consumers. Being part of this innovative project to continuously measure inertia will improve our understanding of how to monitor grid stability in a changing energy environment.”

Intermittency issues

The UK Energy Research Centre notes that costs of absorbing intermittent renewable generation will “vary enormously” depending on the flexibility of the energy system, with grid operators having to account for costs of curtailment, network reinforcements, maintaining system inertia and the reduced efficiency of thermal generation.

Last week, Government figures revealed that low-carbon sources reached a record-high 53.4% share of electricity generation in the second quarter of 2017, with renewables’ share up to 29.8%. While this is good news for the UK’s decarbonisation aspirations, it does place pressure on a grid’s ability to handle increased flexibility, as renewables generate more in favourable weather conditions.

Energy storage is emerging as a potential solution and could mirror how conventional fossil fuel power plants store energy in high-mass rotating equipment, such as steam turbines and gas engines. But the technology is still in its infancy and real-time data analysis will help grids react to the intermittency.

Granular management

Reactive Technologies believe its system, which was funded by Ofgem’s Network Innovation Allowance, can have considerable impact on network re-enforcement decisions, better procurement measures for energy reserve services and the ability to decarbonise the grid further by integrating more renewable generation.

“Grid operators around the world are under pressure to bring new technologies into the control room that allow them to meet their obligations on energy costs, security of supply and decarbonisation,” Reactive Technologies’ chief executive Marc Borrett said.

“We’re giving grid operators access to unique direct data measurements from a national level right down to a granular post code level, so they can operate more leanly and better manage the nation’s supply and demand in line with accurate, real-time information.”

Project SIM uses Reactive Technologies’ innovative GridMetrix solution and builds on its Grid Data Measurement System (GDMS) – a telecoms system that transmits data through the entire National Grid network to broadcast signals on frequency and stability. According to the company, Project SIM could actively measure inertia round the clock for the entire UK grid.

Matt Mace

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