Top Tweets for #CompSec

SPAIN BLACKOUTS: AN ANONYMOUS EXPERT VIEW From a deep groupchat, last night, translated from Spanish, written by an expert in transmission and distribution of power. Not my words. "What has happened on April 28 has a well-located origin: the Aragón-Catalonia corridor, which is one of the most important electric highways in Spain. There is not only the electricity produced by our solar and wind farms in the northeast, but also the electricity that we import from France. This international interconnection, although weak (it can only contribute 3% of our demand, well below the minimum of 10% that marks the EU), in times of stress is essential to balance the network. At 12:32 p.m., in that Aragón-Catalonia corridor there was an electric shock. What exactly does "shake" mean? It means that suddenly and abnormally, the power that flowed through those lines began to vary violently, rising and falling in a very short time. Such abrupt variability can be due to three main causes: 1. That a relay or transformer on that electric highway detects an abnormal flow of current or voltage (higher or lower than expected) and automatically disconnected to avoid burning or destroyed. This is called that "opens" a relay or switch: it jumps and cuts the passage of electricity to protect itself. 2. That the enormous concentration of renewable energy in that area (mainly solar and wind) has created an electrical resonance: electronic inverters, which synchronize current, can sometimes be amplified between them if a small voltage alteration (for example, due to clouds, strong wind or a slight failure) extends like an echo to all devices, causing widespread oscillations. 3. That a wrong control order has been sent (by mistake or attack) from the SCADA systems, disconnecting or reducing the generation of multiple hit plants. There is no confirmation of this possibility yet, but it is being investigated. What is known is that as a consequence of that shake, the interconnection with France jumped: we were isolated just at the worst time, when the peninsula needed external support to stabilize. Without that French help, the frequency of the peninsular network (which should always be 50 Hz exact) began to drop quickly. The frequency is like the heartbeat of the network: if it falls too much, the systems understand that the patient (the network) is collapsing and automatically disconnected so as not to self-destruct. Thus, in just five seconds, the solar and wind farms were turned off —very sensitive to frequency variations—, 15 GW of power was lost suddenly (60% of all the electricity generated at that time), and the network could not take it anymore: it was It collapsed completely, showing the Redeia Platform (REE) a "0 MW" nationwide. That does not mean that all the turbines were physically turned off, but there was no generator synchronized at the common frequency of 50 Hz. It was, for practical purposes, a country off. To ignite a completely dead network again, one essential thing is needed: plants that can start in black, that is, without receiving energy from anywhere else. Spain has identified five large hydroelectric jumps capable of doing this. However, and here is one of the great negligences that are coming to light, three of those five groups were stopped in scheduled maintenance, by business decision supervised by the administration. Only two were operational. That made the recovery much slower and weaker than it should be in a normal contingency plan. The result is that, after almost 10 hours, only 35% to 40% of the national supply has been recovered, and there are still large areas in the dark or under scheduled cuts. The situation reveals a very serious underlying problem: Spain is still an energy island: it only has 3% foreign exchange capacity compared to its total demand."... Cont: