100% renewable energy – at what cost to the marine environment?

05 May 2011 | Article

By Nadine McCormick, IUCN’s Energy Network Coordinator.

Transforming the world’s energy systems is essential to achieving a sustainable global economy. The marine environment offers a bounty of renewable energy options but what do the scenarios look like in reality?

As two-thirds of greenhouse gas emissions come from energy production, increasing attention is being given to the energy sector. Both energy conservation and efficiency measures are being pushed, as well as the development of “clean” (i.e. lower emissions) energy technologies as more immediate ways to reduce emissions in the short to medium term.

Numerous reports are being released from different organizations that show how societies can achieve 80-100% renewable energy supply in the next 20-40 years. A reduction in energy use through both conservation and efficiency measures is critical, together with a massive shift to renewable sources such as solar, wind and waves for electricity and sustainable biomass for liquid fuels and other high energy users such as industry.

Growing investment

This transition is already happening, with huge investments being directed to ‘clean’ energy sources. A record US$ 243 billion was invested in cleaner energy sources globally in 2010, of which China invested US$ 51 billion, more than 20% of the total. Yet, the International Energy Agency has identified social acceptance as one of the main barriers to swift implementation of renewable energy projects, primarily driven by perceived and real environmental concerns associated with large infrastructure on land, such as wind turbines, large solar towers and power lines.

The marine environment is increasingly being targeted as decisions in seascapes are seen as less controversial than on land. However, marine environments have many pressures from shipping, tourism and, fishing and are already among the most threatened ecosystems in the world.

Clean ambitions

WWF’s Energy Report, released earlier this year, is the most comprehensive to date, predicting that 6% of future energy demand can come from the marine environment, primarily through offshore wind, as well as wave and tidal sources. However, this will require an additional 100,000 off-shore wind turbines; 25,000 offshore wind farms are planned in Europe alone.

While wave and tidal energy applications will provide a smaller proportion of future energy supply, according to another report published in the Energy Policy journal, 720,000 wave devices and almost 0.5 million tidal turbines would be required to achieve 100% energy from renewable resources (see list below).

This will undoubtedly have implications for the marine environment.

Managing the trade-offs

As found in the IUCN/E.ON Greening Blue Energy report, proper planning and management of offshore wind farms can help to ensure that marine life is not significantly disturbed and can potentially enhance levels of marine biodiversity. In some cases, energy installations may actually benefit biodiversity by creating artificial reefs or acting as de-facto ‘no-take’ fishing zones.

Proactive rather than reactive planning is needed to ensure that such renewable energy infrastructure goes in the ‘right’ places—right from technical, economic as well as socially and environmentally sustainable standpoints. Measures that can help include sustainability safeguards for energy developments and the promotion of decision-making that involves all stakeholders.

Given the urgent need for low-carbon energy to mitigate climate change, it is increasingly important that the environmental community is part of this process to ensure that any trade-offs are acceptable and consistent with IUCN’s vision of ‘a just world that values and conserve nature’.

Energy resources required to power a world with 100% renewable energy by 2030 (Jacobson et al, 2010) Energy Policy

• 3,800,000 x 5 MW wind turbines
• 49,000 x 300 MW concentrated solar plants
• 40,000 x 300 MW solar PV power plants
• 1.7 billion x 3 kW rooftop PV systems
• 5350 x 100 MW geothermal power plants
• 270 new 1300 MW hydroelectric power plants
• 720,000 x 0.75 MW wave devices
• 490,000 x 1 MW tidal turbines