Offshore Grid Potential in the Mediterranean

The Mediterranean Sea region is becoming increasingly interested in the application of clean energy technologies offshore. The newly published report on the offshore grid potential for the Mediterranean region, prepared by Guidehouse and Sweco for the European Commission, covers the following:

• Nine EU member states in the Mediterranean region: Croatia, Cyprus, France, Greece, Italy, Malta, Slovenia, Spain, and Portugal
• The technical and economic potential and two production scenarios for bottom-fixed and floating offshore wind technologies, wave and tidal energy, and onshore wind and solar technologies on islands
  
• Possible offshore grid concepts
  

The technical and economic potential assessment in this report shows that floating offshore wind is the most suitable technology for the region due to large available areas with favorable wind speeds, suitable water depths, and relatively high capacity factors. These factors result in a technical potential of approximately 4,600 TWh/a by 2030 and 4,700 TWh/a by 2050. Wave energy has a good technical potential comparable to floating offshore wind, but the technology is expected to be more expensive than floating wind and, at currently forecast price reductions, only fits into the European power markets at lesser quantities. Bottom-fixed offshore wind technical potential is rather limited due to water depth constraints in the Mediterranean Sea and is estimated at 60 TWh/a in 2050.

Based on a systematic analysis of resource conditions across the entire EU portion of the Mediterranean, the resulting technical potential estimates, and a levelized cost of electricity analysis, the report identified 10 most interesting technology mix areas (TMAs), presented in the following figure. In most of these TMAs, floating offshore wind presents the best clean energy alternative; in some, bottom-fixed offshore wind presents the best option; and some areas contain a mix of different resources, though overall the report found less mix in the economic potential studies than was originally expected.

Most Interesting Identified TMAs

(Source: Guidehouse)

The production scenarios in the 10 TMAs identify 76 GW (mainly floating) offshore wind potential by 2050—significantly more investment than currently planned by member states—which can fit into the European power markets with limited support mechanisms. This study also concludes that due to the generally deep waters and the large distances between these promising TMAs, one meshed offshore grid solution covering the entire Mediterranean Sea would be uneconomic, in contrast with the generally shallower and windier North Sea. However, the report identifies several subregional hubs that are attractive for linking offshore installations with interconnections. The most interesting options are:

• 03: The TMA southwest of Sicily to link with Italy-Tunisia interconnections
  
• 04: The Gulf of Venice TMA to link with the Italy-Croatia interconnection
  
• 05: The Gulf of Lion TMA to create a Spain-France subsea link, although sea bottom studies suggest that this link could be very challenging environmentally
  
• 07: The North Aegean Sea TMA to combine Greek island interconnections to the Greek mainland
  
• 09: The TMA Corsica-Sardinia to link with Italy-Tunisia interconnections

Examples of Proposed Connection Concepts for the Gulf of Venice and Gulf of Lion

(Source: Sweco)

Further work is needed to develop more detailed solutions and provide further socioeconomic evaluation of such grid solutions. Based on the report’s analysis, Guidehouse proposes that member states and the European Commission do the following to drive offshore energy development:

• Increase R&D, in particular for floating substations, floating offshore wind, wave, and tidal energy
  
• Generate national potential, cost, and grid development analyses
  
• Set up coordination on energy and spatial planning and market conditions for the entire Mediterranean region, including the non-EU and southern shores
  

The results of this report constitute substantial input to the EU’s offshore renewable energy strategy, published on November 19, 2020.