Blackout in UK Brings Issue of Grid Stability and Renewable Power to the Forefront

The blackout on Friday in Britain was the biggest in more than a decade and the evening occurrence caused rush hour travel disruption across the UK’s biggest train stations, railways, roads and airports; besides the homes that went without power.

The blackout, which began at around 5 pm, come at a time when the country is also preparing for a ‘no deal’ Brexit, a situation few had anticipated when the vote first came out on exiting the EU, and has now put many businesses and people on edge.

The National Grid, which runs the country’s power system, has blamed the blackout on a  technical fault at two power generators (gas and wind respectively) and ruled out he possibility of a cyber attack. Blackouts at a grid level are typically caused when the grid frequency deviates by more than a percent on either side of 50 Hz, a level that the operator has to maintain.

Since this frequency is a measure of the energy intensity, or power being fed into the grid, a sudden failure of key generators can lead to shutdown in some parts to maintain overall stability, as it happened on Friday.

The issue has been flagged as a major risk with renewable power for a long time, with doubters regularly wondering just how much renewable supply a grid can handle.

While in places like Germany, grids have proved to be much more resilient than predicted, taking in almost 40% renewable power on days; for countries like India, with rickety network systems, it may not be an easy answer. One of the reasons the government has been pushing for a massive grid overhaul, as it decarbonises.

In the UK’s case, the National Grid ramped up backup power from other providers quickly, within seconds as per their claims. Despite that, it wasn’t until 5:40 pm that the grid stabilised completely.

But by then, the disruption in the transport segment particularly, usually expected to run like clockwork to handle peak loads, was already well under way bringing home the risks to a far larger number of people than the disruption would have entailed.

The event was apparently not as unexpected as one would imagine.

There have been reports of many previous near misses, with their own frequency increasing in recent times.  These ‘near misses’ in grid stability are probably not as widely reported as say, the near misses in case of air traffic control at airports. But the idea is the same.

Near misses themselves have to be avoided as far as possible, for the overall safety and stability of the grid.  In India of course, the nominal frequency of operation is 50 Hz and the permissible frequency band specified by Indian Electricity Grid Code (IEGC) is 49.5 Hz to 50.2 Hz , being followed since 3rd May 2010.