Minesto advances its tidal energy farm development with Dragon 12 upgrades

Swedish tidal energy developer Minesto has finalized the design and technical specifications for its upgraded Dragon 12 tidal energy system, marking a step toward deploying the first Dragon farm at Hestfjord in the Faroe Islands. 

According to Minesto, the project’s Phase 1 targets a capacity of 10 MW and builds on extensive performance evaluations conducted at the Vestmanna site.

Over the past four months, Dragon 12 underwent grid-connected operations and commissioning, during which Minesto focused on assessing power plant performance, optimizing operational procedures, and identifying key system upgrades. 

The review included a third-party evaluation by DNV and a comparative analysis of tidal conditions between Vestmanna and Hestfjord, with the latter confirmed as an optimal site for the upgraded system.

The upgraded Dragon 12 design for Hestfjord integrates site-specific optimizations. While the hardware configuration remains largely unchanged, key upgrades include increasing the generator capacity to 1.75 MW, adapting the wing profile for improved performance, and implementing a longer tether for enhanced production yields, Minesto noted.

“Our work efforts the last months lead to two overall conclusions: firstly, we can offer the lowest cost ocean energy in the world already at our first array build-out and secondly, we have selected a near perfect tidal site for our technology,” said Martin Edlund, CEO of Minesto.

“So, despite obvious cost of energy disadvantages of initially building a small-scale project, we start our journey towards reduction of LCOE at a point where other marine energy technologies hope to end theirs.” 

Minesto said that it is progressing with operational testing at Vestmanna, including campaigns to refine launch and recovery procedures. These improvements aim to enhance efficiency for larger operational campaigns in Hestfjord, where multiple Dragon 12 units are planned.

Recent upgrades have enabled near-shore anchoring of the megawatt-scale kite, optimizing the use of quay side space and improving marine and onshore operational flexibility. 

According to Minesto, site preparations are also underway for commissioning small-scale D4 systems for microgrid customers, with upgrades to seabed infrastructure supporting a 200 kW microgrid Dragon system.

To align with the commercial build-out in Hestfjord, Minesto is manufacturing a longer tether for Dragon 12, extending it by 15% within the limits of the existing marine license. Tether testing will form an important part of the upcoming campaigns, the Swedish company noted.

The transition from research and development (R&D) testing to large-scale commercial operations requires enhanced reliability in critical subsystems and operational procedures. 

“Our development work both on the technical and commercial side focus on the next natural step – array build-out,” Edlund concluded.

In October, Minesto engaged Ernst & Young (EY) to support the development of the 10 MW Hestfjord Dragon Farm, part of a broader plan to deploy 200 MW of tidal energy capacity.

Actual and simulated performance data from Dragon 4 and Dragon 12 showed that Minesto’s tidal energy technology is ready for the first Dragon Farms as well as microgrid installations, the Swedish company’s CEO said.