What hasn't been said about the blackout in Spain

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He will most likely never admit it, but Spanish Prime Minister Pedro Sanchez knows full well that the reasons for the blackout that brought the country to its knees can be traced back to the Spanish electrical model , built on an abundance of renewable sources (and this is a good thing), but with two major limitations .

1) An inadequate system that does not have the systems to manage the parachute offered by gas-fired power plants, hydroelectric plants and all those programmable sources necessary to intervene in the event of a crisis; 2) a network that requires large investments to make it more modern and adequate for intermittent sources.

The necessary race for renewables. In Europe, Spain has developed more than any other production from renewable sources, with a consequent decrease in generation from thermal sources .

Advantageous, but unpredictable . This is an environmentally and economically advantageous transition for everyone, but to be managed it requires a system that can cushion the fluctuations of non-programmable renewable sources .

The ductility of gas . Unlike gas-fired power plants that can be turned on and off like a stove, the energy that comes from photovoltaic and wind power is not adjustable and depends on atmospheric conditions.

The exception . The only manageable renewable source is hydroelectric because the flow of water can be stopped or released as needed.

How the Grid Works . The variability of renewable sources must be managed well. If too much energy enters the grid, the grid explodes. If too little enters, it collapses. It's a bit like pressure in the human body or water in pipes.

To be in balance the network must therefore have a stable frequency between 47.5 and 51 Mhz . Otherwise a blackout occurs.

The situation of the Spanish grid on April 28. In the days preceding April 28, strong frequency oscillations were already occurring and that day the incoming situation of the Spanish grid was as follows: 18,000 megawatts came from photovoltaic plants , 3,500 from wind power , 3,000 from hydroelectric power, 3,000 from nuclear power, 2,000 from self-production, 1,500 from thermal power and 1,000 from gas for a total of 32 thousand megawatts.

Consumption , on the other hand, was concentrated for 25,000 megawatts in Spain, while 3,000 were exported to Portugal , 2,000 to France , 1,000 between the Balearics and Morocco and the remainder for hydroelectric pumping.

The weight of renewables . From these numbers it is clear that on April 28, renewable sources accounted for 79.6% of energy production, a lot, but not something unsustainable if the system had had sufficient brakes available to manage frequency oscillations.

The Spanish model . As for renewables , the Spanish system provides that they are Must run energies, that is, they must be included in the system at all costs because for the final consumer they entail a notable reduction in price.

And in such a system, it may happen that energy producers who use gas-fired power plants prefer to keep them turned off rather than operate at a loss, because they cannot compete with the prices of renewables: under those conditions, their production costs would not even be covered.

Without brakes . The result is that without the regulating plants (gas, hydroelectric, etc.) that guarantee a constant - and emergency - supply and without an adequate network to manage the oscillations for example through compensators capable of regulating the frequency, what happened on April 28 can happen.

The manager did not know what was happening. The network was not up to the task. Certainly, greater digitalization would have been needed: those who managed it during the emergency were unable to trace 40% of the production from renewables . They therefore did not know what was happening on the network.

The blackout . When the oscillation could no longer be managed, the blackout arrived, because the plants disconnected themselves from the grid to avoid damage. 15 thousand MW produced by photovoltaic plants were disconnected and the nuclear power plants themselves activated emergency procedures , leaving the country without electricity.

It starts slowly . The restart was then slower , because restarting nuclear power plants or renewables that do not restart on command is more laborious than restarting gas power plants, which can be reactivated quickly if they are 'hot' (therefore on even if not at full capacity). In this case they were actually 'cold' and therefore had long reaction times.

Safety . There is no doubt that the transition to renewable sources must proceed quickly, but it must be managed safely. And perhaps we cannot yet leave the flexible gas production switched off - looking only at prices and not at the general stability of the system - remaining without a parachute in case of criticality.

Programmable sources . Today, alongside solar and wind, we still need 'programmable' sources that can be managed on command (thermal plants but also hydroelectric with pumping and batteries) and an increasingly modern and efficient network.

Network development . Network modernization involves investments that are remunerated in the electricity sector on the bill . The Spanish tariff system, among other things, provides a cap on investments and, for this reason, they must be planned and managed according to a careful schedule.

The dilemma . If energy is paid for cheaply (and in Spain the cost per megawatt hour is among the lowest among the big ones in Europe), energy companies complain about the lack of capital to invest. But if it costs a lot, consumers complain. The cost of the blackout has been calculated at 40 billion . Now, how many blackouts per year can a country afford?

The solution lies in the middle : consumers cannot be penalized too much, but neither can investments that are essential for a safe transition be stopped. This is where the compromise that Sanchez must find begins.