Cover Story · Beyond Solar desk
143 Megawatts on Paper
Four UK auction rounds have contracted about fourteen times the tidal-stream fleet the country has installed. The awards are counted after every round. What happens to them afterwards is counted nowhere.
The Ecliptic · Issue No. 011 · September 24, 2026
The book
Four rounds, a shrinking award, and no cheaper price.
AR4 contracted **40.82 MW** at £178.54/MWh, AR5 **53.04 MW** at £198.00, AR6 **28.00 MW** at £172.00 and AR7a **20.90 MW** at £190.19, all in 2012 money. The clearing price rose **6.5%** in real terms while the cap rose **26%**.
- The clearing price reads budget scarcity, not cost. AR5 cleared at 98% of its cap because tidal absorbed budget floating offshore wind left unused; AR6, with no windfall, cleared 34% under.
- A flat budget and a flat price make a smaller programme: each £m of ring-fence bought about 2.0 MW in AR4, 1.9 in AR6 and 1.4 in AR7a (Beyond Solar estimates).
- AR8 moves tidal into a sealed ten-technology pot, capped at £371/MWh against geothermal's £219 (2024 prices), with any tidal minimum set only after bids are valued.
The attrition
An award is an option, and the options are starting to lapse.
A CfD must pass a milestone **18 months** after award. The three AR6 Orkney contracts, awarded September 2024, were terminated in **May 2026**, right on that clock. Government has just stretched the milestone to 24 months for floating wind and declined, for now, to do the same for tidal.
- 45.32 MW of the book carries a delivery year ending by March 2027. The Morlais zone, host to 56.52 MW, now expects its first turbines in 2027, a slip of at least a year on its earliest contract.
- MeyGen, holding 58.94 MW, closed June 2026 with £3.6m of cash; its owner calls future phases "challenging".
- The programme publishes megawatts awarded and no equivalent for megawatts delivered, varied or terminated. The May terminations surfaced through counterparty notices, not a programme report.
The array that works
One servicing campaign can erase the margin.
MeyGen's first phase earned roughly **£405–455** per MWh generated in the last two half-years under the legacy scheme. The CfD prices written for tidal's next phase are worth about **£255–293** in May-2026 money. With one turbine of four ashore, operating cost per MWh nearly **doubled**, from about £127 to £245.
- Operation and maintenance is close to a fixed cost; energy is not. Availability, not capital cost, is the binding variable at today's servicing intervals.
- At the H1 2026 output, O&M alone would absorb 93% of the AR4 strike price in current money; at the H1 2025 output, about 48%.
- 43% of the live book sits at the same site, with the same servicing logistics, whose latest capacity factor was about 17% of nameplate.
- Delivery cases for 2030: 136.76 MW if every contract is built, 77.82 MW without MeyGen's next phase, 49.56 MW in the base case (all Beyond Solar estimates).