Green Economy in a Blue World-Full Report

Future energy provided by the oceans

in a Blue World

United Kingdom

France

Russia

USA

China

Japan Ireland

South Korea

Portugal

Australia Finland

India

Projected for 2012 Projected for 2020

Canada

Spain

Italy

0 5 100

3 000

Megawatt

Relative increase of projected capacity

Source: Frauenhofer Institute for Wind Energy and Energy Systems, 2011.

increased more than tenfold from 18 000 MW (end of 2000) to 215 000 MW (June 2011) (WWEA). Owing to ongoing improvements in turbine efficiency and higher fuel prices, wind power is becoming economically competitive with conventional power production (Risø, DTU). China, United States, Germany, Spain and India are among the countries producing the largest amount of (offshore and onshore) wind energy. According to the Global Wind Energy Council (GWEC) China’s wind market doubled every year from 2006 to 2009 in terms of total installed capacity, and it has been the largest annual market since 2009. In 2010, China overtook the United States as the country with the most installed wind energy capacity. China wind capacity in 2010 was 41 800 MW where as that of the US in the same year was 40 180 MW (Financial Times, 2011). Marine energy is unique because its potential varies depending on the energy source, for which there are many technology options. For example, the different concepts for wave energy conversion can be onshore, near-shore and offshore and rely on several working principles (oscillating water columns). Tidal barrage technologies are adapted to ebb and flood tides. Marine current devices are less diversified than wave energy devices, but could use a range of working principles and they can either be rigidly mounted in the seabed, pile- mounted, semi-submersible with moorings or attached to a floating structure. The technology to harness salinity gradient power uses the osmotic pressure differences between salt and fresh water or between water bodies of different salinity.

Little or no convergence has yet occurred, and is unlikely given the range of options for energy extraction (IPCC, 2011). More than 100 different marine-based energy technologies are currently under development in over 30 countries (IPCC, 2011). The four most dominant energy sources are discussed in more detail here. 1.2 Offshore wind energy Offshore wind power is developing rapidly and creating economic opportunities in terms of its share of global energy generation. Estimates of the technical potential for offshore wind energy alone range from 160 to 1 500 million MW in a year; when only considering relatively shallow and near-shore applications; greater technical potential is available if also considering deeper water applications that might rely on floating wind turbine designs (IPCC, 2011). Offshore wind energy is highly capital-intensive when compared to onshore wind energy. The higher offshore capital costs are due to the larger structures and the complex logistics of installing the towers that are significantly higher than onshore. For example, offshore turbines are generally 20 per cent more expensive and towers and foundations cost more than 2.5 times the price of those for a similar onshore project (EWEA, 2009). However, the higher initial capital cost of offshore wind energy is compensated by additional benefits provided by offshore over onshore wind energy. Some of these benefits are listed below: • Greater area available for setting up large projects: due to installation at sea, there is more space available for offshore wind turbines.

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