Utility Week

UTILITY WEEK | 30TH AUGUST - 5TH SEPTEMBER 2019 | 11 Policy & Regulation UTILITY WEEK | 30TH AUGUST - 5TH SEPTEMBER 2019 | 11 Professor Dieter Helm has said that August's power cut should "set alarm bells" ringing for the government and highlights the need for fundamental reform of the energy system. The author of 2017's Cost of Energy Review said that while the blackout of 9 August was dealt with quickly and efficiently, "the key point is that [it] should never have happened in the first place". He said: "If power cuts can happen when just two power generators drop off, then something fundamental has gone wrong." Helm repeated his call for National Grid Energy System Operator (ESO) to be nationalised and regional system operators (RSOs) introduced to co-ordinate the decentralised electricity systems that are emerging. He said the distribution system operators (DSOs) being set up by the distribution companies had conflicts of interest even deeper than those of National Grid. On the potential for a national system operator, he said: "This is not only in the public interest, but argu- ably also in National Grid's interests too. There is little upside to its shareholders from owning the SO, and lots of risk, especially reputationally, as the recent power cut has revealed. "National Grid finds itself in the firing line for things which really are not its business to determine. Who knows what National Grid has been telling BEIS about the security of supply issues, including the conse- quences of more intermittency and the dropping off of coal and soon old nuclear and gas from the systems? This should all be public, between a public authority and the government, not a private company." He said the blackout also underlined the fragility of the system as it becomes increasingly reliant on renewa- bles. This could be tackled, he suggested, by putting "equivalent firm power" capacity auctions at the core of the renewables market. Helm described this as "the capacity auction expanded to take account of the inter- mittency and one that integrates the renewables", with renewables providers incentivised to invest in measures to mitigate their intermittency. "Most renewables are zero marginal cost. That means that there is little long-term future in the wholesale electricity market (which is supposed to reflect mar- ginal costs)." Professor Helm also described nuclear power as "the only large low carbon baseload contender", and said the government needed to commit to a funding model if it is serious about an ongoing role for nuclear. The full text of Helm's analysis is available on his website. The interim report from National Grid Electricity System Operator (ESO) into the 9 August power cut confirmed that it was trig- gered by a lightning strike. The strike at 4.52pm on Friday 9 August on the Eaton Socon, Wymondley Main transmission circuit caused the loss of 500MW of embedded generation. Immediately follow- ing the strike, Hornsea offshore windfarm and Little Barford gas power station almost simultane- ously reduced output. The report said the two power losses were independent of one another but each was "associated with the lightning strike". The report described the event as "extremely rare and unexpected" and stresses that the protection systems on the transmission system operated correctly. It said that while the strike triggered "an exceptional cumulative level of power loss" outside the level required by security standards – sending the frequency plummeting to a low of 48.8HZ – the mechanism of load-shedding to protect the system worked "largely as expected". Following the lightning strike, Hornsea immediately de-loaded from 799MW to 62MW. The report said the initial reac- tion from Hornsea's systems was as expected but very shortly a¨erwards, as the reaction expanded throughout the plant, the protective safety systems activated. It said that following an initial review, adjustments to the wind farm configuration, and fine-tuning its controls for responding to abnormal events, it is now operating "robustly to such millisecond events". Near instantaneous to the de- loading at Hornsea, Little Bar- ford gas power station tripped with the immediate loss of 244MW from the steam turbine unit. RWE confirmed that a¨er approximately one minute the Key findings of Grid's preliminary report Dieter Helm first gas turbine tripped because of excessive steam pressure in the steam bypass system. The second gas turbine was manu- ally tripped by staff in response to high steam pressures around 30 seconds later. DNO response The 26-page report insisted that the transmission system operated in line with security standards and the grid code. The final report, due by 6 September, will seek to under- stand the exact failures at Little Barford and Hornsea and update on work with the distribution network operators (DNOs) to review the impact on demand and priority of disconnections. It will also review ESO communications, which the preliminary report said were not as rapid as it would have liked. Ofgem has now officially launched its investigation, which will decide whether any of the parties involved breached their licence conditions. JW Helm: outage underlines need to renationalise National Grid Power surge tripped Hornsea off the grid

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