A widespread power cut that took place on the 9th August and which left nearly 1 million customers without power is now under investigation. The event, which was caused by a lightning strike, left large parts of England and Wales without electricity and had a serious impact on rail and road services. The government department for Business, Energy and Industrial Strategy (BEIS) as well as the Energy Emergencies Executive Committee’s (E3C) will be looking into the event to identify actions that need to be taken.
Two large energy generators, a 727MW gas-fired facility operated by RWE and Orsted’s 1.2GW Hornsea 1 offshore wind farm, disconnected from the grid system within minutes of each other, causing the power cut. The result was a sudden, major drop in the nation’s electricity supply with more than one gigawatt of power lost from the system. National Grid had to reduce load on the grid by forcibly cutting selected customers off.
Following the event, it needs to be determined if there were any technical issues and examine whether the correct procedures and processes were followed. BEIS published its full terms of reference and scope for the Energy Emergencies Executive Committee’s (E3C) investigation into the matter on the 15th August. An interim review is timetabled for within five weeks and a final report is to be submitted to the energy secretary within 12 weeks.
This investigation will involve looking into matters involving the electricity system operator and transmission system, which are both the responsibility of National Grid as well as distribution network operators (DNOs) and generators. DNOs and the decisions they make to disconnect end users will be investigated as part of the inquiry, the government has confirmed. The investigation will also consider how end users are prioritised when low frequency demand disconnection (LFDD) is called upon. Questions were raised over the prioritisation of these disconnections; LFDD is ultimately called upon when other measures aimed at stabilising the grid such as frequency response fail or cannot meet the demand.
Although the power was brought back on within just over 40 minutes, the event highlights the importance and the need for even more energy balancing systems, such as battery and peak power schemes which can store and release electricity to the grid under these emergency situations. This instance could have been much worse without a current fleet of batteries which kicked in across the country and helped to prevent a rapid drop off in transmission frequency.
This requirement is particularly important as we continue to rely on renewable energy schemes, which are generally less reliable in terms of their generation in normal running conditions than traditional fossil fuels.
This month’s feature article was produced by Alison Cheetham, Senior Energy Specialist at Carter Jonas.