Summary
- Orcadian models private-wire electricity for Earlham at about £124/MWh under specified cost, return and carbon assumptions.
- Its separate carbon-capture model estimates an incremental cost of about £11 for each tonne of CO₂ captured.
- Both calculations remain internal and unaudited while Earlham continues through concept selection and validation.
Orcadian Energy has put indicative power economics around its Earlham Gigagrid concept, estimating that an offshore compute operator could receive private-wire electricity at approximately £124/MWh under the company’s current development assumptions.
The calculation follows the termination of Orcadian’s first joint development agreement for Earlham after the proposed development timetable failed to align with its US partner’s near-term deployment requirements. Orcadian retains the relevant licence and says discussions with other potential partners are continuing.
The new economic model does not alter the physical status of the project. Earlham remains at concept stage, with no offshore data centre under construction, no generating plant commissioned and no validated final engineering configuration for the computing infrastructure.
Orcadian calculated the £124/MWh figure as the electricity price required to deliver a 20% target return for the gas development and 15% for the power station over a 20-year operating life. The model also assumes that UK Emissions Trading Scheme and Carbon Price Support charges apply only to the 5% of carbon dioxide not captured and that no Climate Change Levy is charged.
The company explicitly states that the estimate is internally generated, has not been independently verified and remains sensitive to gas prices, capital costs, utilisation and the target rates of return. Those conditions prevent £124/MWh from being treated as a contracted or independently validated electricity price.
Private wire changes the connection route
Earlham is conceived as an islanded offshore system in which gas from the field would be converted into electricity close to computing infrastructure instead of supplying a conventional land-based data centre through the public electricity network.
Orcadian compares its model with a 2026 government figure of £218/MWh for extra-large industrial electricity consumers. The comparison illustrates the economic proposition but combines different infrastructure and risk structures.
The grid figure reflects electricity supplied through an established power system. Earlham’s estimate depends on new offshore gas production, generation, carbon capture, computing hardware, cooling, fibre and associated marine infrastructure being financed, built and operated successfully.
The company is also studying rack densities above 300kW as a way to reduce the amount of offshore space required for a given level of computing capacity. Higher rack density can shrink the physical footprint, but it increases the concentration of electrical and thermal load inside each enclosure.
Offshore deployment adds further engineering constraints because equipment has to operate within limits on structure, weight, access and maintenance while using cooling and connectivity systems suitable for a marine environment. Orcadian identifies marinisation, seawater cooling and consenting among the questions still requiring work.
Carbon capture remains part of the cost model
Orcadian has separately estimated the incremental cost of capturing and storing carbon dioxide at roughly £11 for each tonne captured when discounted at 10%. It gives an equivalent figure of about £39 for each tonne of carbon.
That calculation is also internally generated, unaudited and not independently verified. It excludes emissions-trading and similar charges that Orcadian says would improve the relative economics of carbon capture.
The proposed energy system is intended to capture around 95% of the carbon dioxide covered by the model before offshore storage. Actual emissions performance would still depend on the final generation plant, capture rate, upstream gas emissions, auxiliary power, operating profile and any backup systems.
Power price and carbon performance are therefore linked to engineering decisions that remain open. A higher construction cost, lower utilisation rate or different capture performance could materially alter the electricity price required to achieve Orcadian’s target returns.
The modelling nevertheless defines more of the assumptions that a future development partner would need to test. It provides target economics around the energy system rather than leaving Earlham only as a conceptual description of offshore computing supplied by local gas.
The recent failure of the first development agreement also shows why those assumptions need to be tested against customer timescales. Compute operators can procure hardware and contract capacity on a shorter cycle than offshore energy infrastructure can pass through concept design, finance and consenting.
Earlham’s next significant step would therefore be independent engineering or economic validation, or another partner willing to fund that work. Until then, the £124/MWh figure is a development model tied to specific assumptions rather than the realised cost of operating offshore data centre power.
