by Tom Young, businessgreen.com, 04.15.2011

1 Desertec
The theory behind the ambitious Desertec project is that there is more than enough solar power falling on the deserts of North Africa to power all of Europe. Recent developments in the fields of concentrated solar power and high voltage direct current cables mean that the power could be harnessed by huge solar arrays, transported across the Mediterranean, and distributed through Europe relatively efficiently.

Twelve European companies have already invested in making the idea a reality and test projects are due to start in Morocco in 2012. By 2013 the group will decide whether the foundation will seek the $600bn necessary to make the project a reality. If so, the initiative could be completed within two years.

In an interview with an Egyptian paper last month Hani Nokraschy, vice chairman of the supervisory board of Desertec, said that the uprisings in Egypt and Tunisia are seen as uniformly positive by the Desertec board, which believes that new regimes will be more open to the idea.

2 Desertec Australia
Some believe that Australia could become Asia's solar powerhouse in the same way that North Africa could become Europe's. Like Africa, Australia has huge solar potential, and basic calculations indicate that the Desertec Australia scheme would cost between $2.5tn and $5tn, spread over many years.

In a similar way to the Africa project, high voltage direct current cables could be used to transport the power to the growing economies of Asia. And proponents believe that costs could be brought down by laying the infrastructure alongside an expansion of the natural gas grid in Australia and new pipes being constructed to pipe liquid natural gas between Korea, China and Japan.

They also believe that the energy could also be used to power a domestic electric car revolution in Australia.

3 The UK's Round Three offshore wind farms
The UK is hoping eventually to install some 40GW of offshore wind capacity around its coastline, 25GW of which is hoped to be operational before 2020 as part of the so-called Round Three projects.

These targets are hugely demanding on a number of fronts: a supply chain needs to be developed from scratch; new, larger offshore windturbines need to be produced; and subsea grid infrastructure has to be laid to link the wind farms to the mainland.

But the UK is already the world's largest producer of offshore windenergy, and has well-established marine engineering skills as a result of the North Sea oil and gas boom, and a policy environment that currently has developers and investors lining up to develop the world's largest offshore wind programme. 

4 China's Jiuquan onshore wind farm
The world's largest onshore wind farm is the 780MW Roscoe facility in Texas. But it will soon be eclipsed by the Jiuquan Wind Power Base in the Western Gansu province of China.

The Jiuquan project is expected to reach 20,000MW of capacity by 2020, at an estimated cost of ¥120bn (£10.7bn). Construction began in 2009 and development will be in phases over the next 10 years. Authorities are also constructing a 750kV grid infrastructure to help transport the power to the populous eastern seaboard.

5 The Severn tidal barrage
Completed in 1967 at a cost of approximately £82m, the Rance tidal barrage remains the world's largest. However, the UK has proposed a number of different options for a tidal power barrage across the Severn estuary, the largest of which would be a 7.5 mile dam that could produce 8.6GW of energy, far outstripping the capacity of the Rance barrage.

Late last year, an official study said that there was no "strategic case" for investing public money in the scheme, which could cost up to £30bn. However, it did not rule out investment in the project at a later date and proponents hope its time will come again. 

6 The Wando Hoenggan project
The 1.2MW SeaGen tidal power turbine in Strangford Lough, Ireland is currently the biggest commercial-scale tidal power turbine in the world.

But by 2015 it will be surpassed by a massive tidal power turbine project in the Wando Hoenggan waterway off the coast of South Korea. The project will be built jointly by the UK's Lunar Energy and Korean Midland Power Company for $820m.

Over 300 1MW turbines will be anchored to the seabed by their own weight. Each has a 2,500 tonne frame into which a "cassette" containing a pump, generator, motor and electronics are dropped.

7 The Tsangpo-Brahmaputra hydroelectric dam
China's Three Gorges dam produces 14.1GW, making it the largest and most productive hydroelectric dam in the world. But plans have emerged for a 38GW hydropower dam on the Tsangpo-Brahmaputra river that would be more than half as big again, with a capacity nearly half as large as the UK's entire national grid.

The Tsangpo-Brahmaputra was until recently considered the last great undammed river in Tibet. However, the Indian government has already raised concerns that any further upstream damming of the river will affect citizens' water supply and the project is likely to face stiff opposition from environmentalists.

8 The Geysers
It is perhaps an indication of the geothermal industry's failure to maintain its early momentum that the largest planned geothermal project is smaller than facilities currently in operation.

An $800m geothermal project slated for North Sumatra finally got underway last year, headed by Indonesian oil and gas company Medco Energi Internasional.

But even when it's finished, the 330MW facility will seem small compared to the Geysers, a geothermal field in California, which started out at 1.5GW when it was developed in the 1970s, then peaked at 2GW in 1987 before sinking back to about 700MW today.

9 Ivanpah solar power facility
Final approval for the 370MW Ivanpah Solar Power Facility, located 40 miles southwest of Las Vegas in the Mojave desert, was granted in October last year.

It is the world's largest solar-thermal power plant currently under construction. It is being built by BrightSource Energy, a California-based firm that recently received a $1.37bn loan guarantee from the US Department of Energy to support the project.

The completed facility will deploy 347,000 heliostat mirrors to focus solar energy on boilers positioned on centralised solar towers. The receivers will then generate steam to drive specially adapted steam turbines.

10 Kashiwazaki-Kariwa
The Kashiwazaki-Kariwa nuclear plant on the west coast of Japan has been the largest nuclear generating station in the world since 1997. It has seven operating units and a total capacity of 8GW.

It was completely shut down for 21 months following an earthquake in 2007, but went largely unaffected by the recent 2011 earthquake. Nuclear plans worldwide have suffered setbacks as a result of unfolding events at the Fukushima nuclear plant, and no plant larger than Kashiwazaki-Kariwa is tabled for construction in the foreseeable future.