Power grid operator requirements to the solar stormsciense society

Transcription

1 Power grid operator requirements to the solar stormsciense society Space technology for sustainable energy management Kåre Rudsar Brussels 6th June

2 Introduction What we need, and only thing we need. A GIC forecast that is precise and reliable as many days as possible before the storm hit the earth. (ideally 4-5 days)

3 Facts Statnett Norwegian Transmission System Operator (TSO) Owner of km of high-voltage power lines Owner of more than 200 transformers in use placed in around 150 sub stations around Norway. Transformer Weight: 300 tonn Cost: 2,2, million Euro ++ Replacement time: 2-3 weeks (in-house) Delivery time for spare parts, replacement unit from producer: 18+ months

4 Solar Storms and the electricity grid

5 Statnett options to prevent GIC related power-system breakdown 1/3 Put "all" lines and transformers in operation to reduce the impact of GIC. Costly At any time there are lines and transformers out for revision, often planned years ahead. Revisons are costly and most cost will not be refunded. Time consuming To stop ongoing or planned work on the lines, in a safe and coordinated way, takes time, and it takes time to put lines and transformers back in operation. Risk Option 1 put the Norwegian power supply system at stake. If there is a system collapse with breakdowns of lines and transformers there may be regions without power for days and weeks.

6 Statnett options to prevent GIC related power-system breakdown 2/3 -To carry out planned blackouts in parts of Norway. -To decouple a number of lines and transformers that can be used after the storm. Consequenses -Extremely high consequenses for the society, and extremely costly. -The risk that the remaining lines and transformers in operation will break down increases. Time-consuming It takes days to shut down the grid, and it takes days to restore it.

7 Statnett options to prevent GIC related power-system breakdown 3/3 Protective Measures Soft measures Recalibration of protection system and rising of trip level Modification of power system operating procedures Buy transformers designed to be more robust to handle GIC Hard Measures Neutral blocking device (more than 220 transformers) Series capasitors compensation of transmission lines ( km high voltage power lines) Neutral capacitor blocking device Active cooling of transformers What do Statnett and other grid operators do Soft measures are executed. Hard measures are costly, and will probably only be seriously considered if GIC cause serious breakdowns in Europe

8 What dilemmas do we face when it comes to solar storms? The economic, social, technical and even political consequences of doing nothing in case of a Carrington storm may be enormous for the entire society. But, "no" harm by doing almost nothing so far We can "shut down" our systems, but to do this in a controlled way will take days. The economic and social consequences will be enormous. Nobody would dare to take that decision based on today's uncertain forecast "Shutting down" the system based on a false alarm will make it almost impossible to act up to a solar storm forecast again. Better sorry than safe

9 Conclusion We think that a Carrington storm will hit the earth sometimes in the future But Current forcasts is to vague, to uncertain and comes to late to enforce any action. We do not know enough about the destructive effect of solar storms to invest in hard measures. NERC (The North American Electric Reliability Corporation) is turning its focus from protection to planning/handling of solar storms

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