U.S. PETROLEUM INVENTORIES including the strategic reserve depleted by -12 million barrels in the seven days ending on May 19 to the lowest seasonal level since 2004. There was a major drawdown in commercial crude stocks (-12 million barrels) with smaller draws in gasoline (-2 million) and distillate fuel oil (-0.5 million) but a small build in jet fuel (+1 million). Commercial crude stocks are in line with the prior ten-year seasonal average (+0.01 standard deviations) but there are substantial deficits in gasoline (-1.20 standard deviations) and distillates (-1.45 standard deviations):
¹ This article seems to be merging the related but separate concepts of rotating power cuts to cope with possible electricity shortages caused by insufficient gas-fired and renewable generation this winter with restarting the grid after a total failure such as might be caused by an accident or sabotage.
“Yarrow” sounds like a plan for a “black start” of generation, transmission and distribution systems following complete failure. Electricity network managers in the United Kingdom and other countries have planned for a black start for decades. It is one of those remote “high impact low probability” risks commonly used in scenario planning.
The United Kingdom has never had to undertake a nationwide black start though a regional one was necessary in parts of the southeast following damage caused by the Great Storm of October 1987.
Black starts involve a complicated series of steps and would take several days to complete. Designated generating units would have to be started up autonomously, following by limited energisation of the transmission grid, first regionally and then nationally.
Black start sites often have auxiliary diesel-fired generators maintained at a high state of readiness that can restart without external power. The auxiliary generator is then used to start one or more main generators (usually oil, coal or gas-fired) on the same site which are then reconnected to the grid.
Progressively more generators would be started up and synchronised to the network, which would start to provide limited power to the local distribution systems. Protected sites would start to receive power and then more customers as sufficient power becomes available.
The process could take up to 5-7 days in the event of total failure. In the meantime most customers would receive no power or be subject to rotating power cuts to limit demand while generation is restored gradually.
The complexity and time needed for a full black start explains why grid managers attempt to avoid them at all costs. Temporary but controlled load-shedding directed by grid managers is preferable to uncontrolled cascading failure of the power grid leading to collapse and forcing a black start.
Black start should be a very remote risk in a well-run grid. But the sabotage of the Nord Stream pipelines has focused attention on the risks of deliberate attacks on energy infrastructure and will make black start a higher priority for emergency planners.
EUROZONE manufacturers reported an accelerating decline in activity last month as the region’s economy was hit by inflation, soaring energy prices, supply chain problems, Russia’s invasion of Ukraine and the EU sanctions imposed in response. The composite purchasing managers’ index slipped to 46.2 in October (12th percentile for all months since 2006) from 48.4 in September (24th percentile) and 58.3 in October 2021 (92nd percentile). The composite index has been below the 50-point threshold dividing expanding activity from a contraction for four months running, confirming the zone’s economy is entering a recession:
JKempEnergy.com 