\n The biggest question, though, for us in the UK, is what does it tell us about the risks to our own grid and what needs to be done, in an era of expanding renewables, to mitigate them.\n<\/p>\n
\n READ MORE:\u00a0<\/strong>\n<\/p>\n \n Not surprisingly the outages have also triggered speculation around the role that Spain\u2019s high proportion of renewables may have played.\u00a0 On April 28, data shows solar photovoltaic (PV) energy was providing almost 59% of Spain’s electricity at the time of the blackout, while wind power was providing nearly 12%, nuclear almost 11% and combined cycle gas plants 5%.\n<\/p>\n \n S\u00e1nchez, however, has also said that there was not a problem with renewable energy access during the outage.\n<\/p>\n \n Nevertheless, some have speculated that the problem may have been the lack of what is called \u201cinertia\u201d in the Spanish system at the time.\n<\/p>\n \n What exactly is this inertia? Energy expert John Kemp in a blog on the Iberian blackout explained: \u201cThe\u00a0massive rotating generators\u00a0in thermal power plants (coal, gas and nuclear) as well as hydro generators can help the grid self-stabilise because they have enormous amounts of\u00a0inertia\u00a0and store huge amounts of\u00a0kinetic energy. In the event load exceeds generation, rotating generators supply some of this stored energy back to the grid \u2013 losing momentum in the process with a corresponding decline in grid frequency.\u201d\n<\/p>\n \n It’s the energy in such turbines that have\u00a0helped balance the UK grid over decades.\u00a0\n<\/p>\n \n Solar and wind generators, Kemp\u00a0wrote, \u201cdo not ordinarily provide inertia and frequency control services, unless fitted with specialist equipment\u201d.\n<\/p>\n \n \n He also cited a multi-year study called\u00a0Project Inertia\u00a0by the European Network of Transmission System Operators for Electricity\u00a0which examined the risks of system splits like the one which just occurred in the European grid, describing them as \u201cserious, challenging, and realistic disturbances that push the interconnected system to the limits of its dynamic stability and incur the risk of large-scale blackouts\u201d.\n<\/p>\n \n It should be noted that the UK’s power grid is not directly synchronised with the Continental\u00a0Europe\u00a0Synchronous Area\u00a0grid (one of the largest synchronous grids in the world), but does trade electricity with European countries via subsea cables.\n<\/p>\n \n Kemp wrote: \u201cThe extent to which the high share of renewables on the Iberian grid contributed to the loss of\u00a0pre-disturbance reliability\u00a0and\u00a0post-disturbance resilience\u00a0is unknown but will come under intense scrutiny.\u201d\n<\/p>\n \n But others, like Daniel Muir, senior European power analyst at S&P Global, have dismissed the idea that the high proportion of renewables was a factor.\n<\/p>\n \n \u201cThe nature and scale of the outage makes it unlikely,\u201d Muir said to Politico magazine, \u201cthat the volume of renewables was the cause, with the Spanish network more often than not subject to very high volumes of such production. There was sufficient conventional generation available, with nuclear, hydro, cogeneration and thermal technologies all on the system prior to the event and … available to the operator.\u201d\n<\/p>\n \n This isn\u2019t the first time that the Iberian Peninsula was hit by a separation from the rest of the Continental Europe (CE) transmission system. In 2021, a wildfire near transmission lines carrying electricity from southern France to Spain triggered such an event, though the whole system did not collapse.\n<\/p>\n \n Of course the \u201cinertia\u201d problem is just one theory.\u00a0 And even if it was an element in the issue, it should provide a reminder of the need to factor other types of balance, like battery storage, into the system\u00a0in a renewables-heavy grid. Some visions of a future grid revolve as much around smart solutions involving\u00a0battery storage and solar PV at a domestic level as they do major infrastructure.\u00a0\n<\/p>\n \n Professor\u00a0Keith Bell\u00a0ScottishPower Chair in Smart Grids at the University of Strathclyde\u00a0said: \u201cAs of Tuesday morning, it\u2019s very good to see that almost all demand for electricity in Spain and Portugal has now been restored.\n<\/p>\n \n \u201cIt\u2019s not yet clear to me what happened to cause this very large outage.\u201d\n<\/p>\nWinds of Change on the Iberian blackout (Image: Derek Macarthur)\n<\/p>\n