16.3.2015 14:30
Current News, Power System, Electricity Market

Preparing for the solar eclipse on 20 March 2015

On Friday, 20 March 2015, at 9.40 am to 1.50 pm Finnish time, a partial solar eclipse will be seen throughout almost all of Europe. In the Nordic countries, the eclipse will have no impact on the functioning of the power system, since solar electricity production is minor. However, in continental Europe the eclipse can have a significant effect on the momentary balance between consumption and production.
If the weather is clear to begin with, the production from solar panels decreases up to more than 30,000 megawatts in one hour across the entire continental Europe. As the eclipse ends, the panels return to producing electricity and the power system experiences a corresponding increase in power. At its greatest, the rate of change in power caused by the eclipse may be several hundred megawatts in a minute.
The impact of the solar eclipse will be most conspicuous in Germany and Italy, where the installed solar electricity capacity is greatest. European TSOs have prepared for the solar eclipse well in advance and are ready to e.g. obtain more reserves to control the situation, and thus the eclipse is not expected to endanger the operational reliability of the electricity network.
The effect of the solar eclipse on the market is strongly dependent on the clarity of the weather during the eclipse. If the weather in continental Europe is clear, Nordic TSOs limit their import capacity to continental Europe to the level of 800–1,000 megawatts and export capacity to the level of 3,000–4,000 megawatts to maintain operational reliability. The total capacity is divided among connections in proportion to their nominal power. The connections' automatic regulation properties are kept in use to support the power balance in continental Europe. Normal ramping restrictions from hour to hour are in use.
Nordic TSOs will inform the market again before the eclipse if there is reason to take further measures to secure operational reliability due to the weather forecast or other reasons.
More information on the solar eclipse can be found on the website of the European TSO cooperation body ENTSO-E:
You can see an animation of the solar eclipse by clicking the link below:
Further information:
Timo Kaukonen, tel. +358 30 395 4228