Impressive figures – valuable lessons
The past year was once again an interesting year of strong production in Olkiluoto. It was the first year that saw us produce electricity at three plant units the whole year. Annual outages, which are regular and critically important high-effort events in the nuclear field, were also carried out in triple. In addition to the impressive amount of watt-hours, we also learned a lot of valuable lessons for the future in Olkiluoto.
Last year, a total of 23.26 terawatt hours of electricity was produced on the Island of Olkiluoto. That is a lot of electricity. We can all feel good about this production volume. At our two older plant units, production remained at the good level which has proven quite stable. The availability factors of the plant units also stayed high, as per usual, with OL1 boasting an availability factor of 89.2 percent and OL2 a factor of 84.9 percent.
Our newest plant unit Olkiluoto 3, which started in regular electricity production in April 2022, reached an availability factor of 76.1 percent. Every professional in the industry will confirm that this can be considered an excellent availability factor at the early stages of the plant unit’s life cycle. Overall, in investments of this magnitude, and particularly in the nuclear sector, teething problems are more a rule than an exception. Although OL3 has had its share of them, their number has been quite moderate. Apart from the annual outages, the plant was only off production for 108 hours.
Equally great was the total production of OL3 in 2024 at almost 10 terawatt hours. In other words, this single plant unit produced almost one eighth of all electricity consumed in Finland last year. That amount is almost as much as the amount imported into Finland from Russia every year until a few years ago. As we all know, that option is now non-existent. The start of production at OL3 could not have happened at a better time in that sense either.
However, there is no point in looking only at production figures, as the essential question in the changing energy field is the availability of electricity when demand is at its highest. As a result of the change in the energy field, there has even been over-production of electricity in the Finnish market from time to time. This has been reflected also here in Olkiluoto as elasticity of production at the plant units. In other words, the plant units are operated at full power output when demand for electricity is high, but operation can also be reduced when conditions change. This is a fairly new concept also for us, but the experience has been very promising. The operability of the plant under any circumstances is the priority that we will always adhere to also with this concept.
The overwhelming advantage of nuclear power in all situations is its reliability of production and particularly its independence from weather conditions. Whether sunny or cloudy, windy or not, our plant units produce electricity and their production can also be regulated, if necessary. Also in 2024, electricity was produced in Olkiluoto every day and every hour of the year. That is true also on these windless January days with plummeting temperatures when the demand for electricity is at its highest.
When we add to our numbers the watt hours produced by our colleagues in Loviisa through their valuable efforts, we can conclude that as much as 37.6 percent of all electricity needed in Finland last year was produced with nuclear power. Stable – safe and clean.
Strong nuclear power is excellent news also to the environment. The share of clean electricity is crucial in the battle against climate change. In Finland, we are pioneers in this work. Last year, clean electricity accounted for a handsome 95 percent. This is something that many countries can still only dream about, unfortunately.
In March, we will again face the annual outages which play a key role in securing nuclear safety and stable production. This will be the second year of annual outages carried out at three plant units. Last year’s service outage was the first at OL3 and we gained a lot of valuable knowledge from it. That means we are now even better prepared for the upcoming challenge. Once again, it is going to be a gigantic show of effort implemented by more than a thousand people, including hundreds of external professionals of various fields in addition to us, the natives of Olkiluoto. Preparations for this have been ongoing for quite some time already. In practice, the planning work started even before last year’s outages were completed in the spring.
But more about that later. I want to thank everybody for a great year and wish you all an energetic this year!
The text was written by Marjo Mustonen, Senior Vice President, Electricity Production, at TVO.
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