The Darlington SMR Project now has an official estimated LCOE of ~€95/MWh for four BWRX-300s When I last wrote about the four BWRX-300 reactors being built at Darlington, Ontario Power Generation (OPG) had not disclosed the expected LCOE for the project. That number has now been made public by OPG in a answer to the Ontario Energy Board. OPG projects an average LCOE of C$149/MWh in 2024 dollars, equivalent to around €95/MWh in 2025 euros, across the full four-reactor project. Unit 1 is planned to enter service in 2030, with all four units expected to be in operation by 2035. This is particularly interesting in the context of the construction costs I looked at in my previous post. After adjusting OPG’s headline project budget for escalation and interest during construction, I estimated an average overnight construction cost of around €8,200/kW across the four units in 2025 euros. The estimated OCC declined significantly through the build programme, from around €10,700/kW for Unit 1 to €6,900/kW for Unit 4. The €95/MWh is therefore an average that includes the first-of-a-kind (FOAK) BWRX-300 together with the three subsequent units benefiting from repetition, shared infrastructure and learning. OPG has not published individual LCOEs for the four reactors, but the substantial decline in capital cost towards Unit 4 would, all else equal, also be expected to translate into a lower LCOE for the later units. There is of course still uncertainty around the estimate. Unit 1 and the shared infrastructure have reached OPG’s Release Quality Estimate (RQE), based on a Class 3 cost estimate, while Units 2-4 are currently based on Class 4 estimates and will be refined as engineering progresses and experience from Unit 1 is incorporated. So €95/MWh should not be read as a final realised cost, but it is a useful real-world benchmark for a four-unit SMR project already under construction, and one that already includes the FOAK reactor.