Report says offshore wind could beat onshore wind on cost

Onshore wind is one of the cheapest sources of renewable power. However, without change to planning restrictions, Cornwall Insight estimates offshore wind is likely to surpass onshore wind power to be the new source of cheap renewable energy in less than 10 years.

Offshore wind has seen significant innovations, such as higher turbines with longer blades, allowing it to capture more of the wind.

The levelized cost of energy (LCOE) of offshore wind could fall below onshore wind by 2028. The projections are based on capital costs by technology, fixed and variable operational costs, expected hurdle rates, and locational factors such as transmission losses and connection fees, and using the current load factors for offshore wind at 58.4% and onshore wind at 38%.

“The renewable energy market is under a process of transition with onshore wind facing the real prospect of being usurped by its offshore cousin to be the cheapest source of clean power in the not so distant future,” said Tom Edwards, senior modeller at Cornwall Insight. “Improvements in offshore technology are occurring all the time and for offshore wind increasing the size of turbines is making a significant impact. With 8 MW models currently being deployed, and larger 10 MW and 12 MW models under development as the technology advances. With these larger economies of scale, it is inevitable that costs will fall.

Edwards said the playing field is not level in Great Britain when it comes to these comparisons. Analysis by the Onshore Wind Cost Reduction Taskforce found that LCOE savings of £4MWh to £7MWh were possible with tip height and rotor diameter optimization for onshore wind. The latest turbine specifications claim to improve load factors by as much as 26%.

“While restrictions on onshore wind turbine height are maintained, projects will be unable to take advantage of these improvements to reduce costs,” Edwards said. “For onshore wind to keep pace with its offshore counterpart, planning decisions will need to be relaxed. This will not only to benefit consumers with cheaper cleaner energy but help the government towards its decarbonisation targets, not only in terms of facilitating the best conditions for new build onshore wind but also allowing existing sites to be repowered optimally.”

Cornwall Insight provides research, analysis, consulting and training to businesses and stakeholders engaged in the Great British and Irish energy markets.