Olkiluoto produced about a quarter of Finnish electricity in 2025

Teollisuuden Voima's Olkiluoto complex produced 23.41 TWh in 2025 — roughly a quarter of Finnish electricity demand — driven by OL3's uninterrupted output of 10.38 TWh and an 82.6% availability factor following final acceptance in June. OL1 delivered 7.49 TWh with 96.2% availability (only a brief ~25‑hour outage), while OL2 produced 5.55 TWh with 71.2% availability after a ~three‑week generator rotor fault and is being operated at 735 MW until its 2027 outage to mitigate risk. The addition of OL3 and uprates materially increased baseload nuclear supply and strengthens Finland's low‑carbon generation profile, though OL2's derating and extended outage duration are operational risks to monitor.

Analysis

Market structure: A reliably running OL3 (10.38 TWh) and total Olkiluoto output (23.41 TWh ≈ 25% of Finland) meaningfully increases low‑marginal‑cost baseload supply in the Nordics. Expect Nordic baseload forward prices to re‑price lower by ~10–15% over 6–12 months versus previous curves as nuclear displaces gas/coal hours and increases export capacity into Sweden/Baltics.

Winners & losers / competitive dynamics: Winners are low‑cost, nuclear‑exposed utilities and Finnish industrial consumers; losers are gas/coal peaker generators and merchant thermal players (higher variable costs) whose hours and spark spreads compress. Cross‑border flows increase, pressuring TTF demand and potentially reducing EU gas vol demand by an estimated 5–10% in non‑extreme weather years.

Cross‑asset & risks: Commodities (TTF gas, coal) should face downward pressure—bearish for commodity producers and LNG freight; lower energy‑driven CPI upside improves sovereign spreads slightly (Nordic IG tighter) and flattens near‑term real rates. Key tail risks: prolonged OL3/OL1/OL2 outage, regulatory shifts on nuclear waste or political curtailment, or an unusually cold winter that spikes demand.

Catalysts & monitoring: Near term (days–weeks) watch Nordic forward curve moves and TTF 1–12M futures; medium term (3–12 months) watch OL2 rotor repairs (reduced to 735 MW until 2027) and the planned OL3 outage in autumn 2026 which can re‑assert scarcity premiums. Material reversals will come from unplanned outages >30 days or EU gas storage <70% by October.

Key Decisions for Investors

• Establish a 2–3% long position in Fortum (HEL:FORTUM) over 6–12 months — thesis: Finnish nuclear supply tailwind and lower operating risk vs peers; target +18–25% total return, stop‑loss 12% if Nordic baseload forward for 12M rises >5% from current levels.
• Initiate a 1–2% short position in Uniper (UN01.DE) or comparable gas/merchant generator exposure — thesis: compressing spark spreads and weaker TTF lower merchant profitability; target -15% in 6–9 months, cover if Uniper announces >€1bn hedging/capacity support or Nordic baseload rallies >10%.
• Purchase 6–12 month puts on TTF gas (size ~1% portfolio eq.) or buy a put calendar (Dec expiry) to express downside in gas prices — aim to hedge seasonal volatility; add if TTF 3M futures fall >15% or EU gas storage >80% by Nov.
• Implement a pair trade: long HEL:FORTUM (2%) vs short RWE.DE or UN01.DE (1.5%) to capture relative upside from Finnish nuclear vs German thermal exposure; rebalance if Nordic vs German power spread narrows <€2/MWh.
• Set an event trigger rule: reduce net long nuclear/utility exposure by 50% if any Olkiluoto unit suffers an unplanned outage >30 days or if Finnish regulator announces restrictive nuclear policy within 60 days — this protects against the largest tail downside.