The World’s Biggest Green Energy Projects

As the world struggles to get more of its power from renewable sources amid rising demand for electricity, renewable energy projects are growing.

This is especially true in China, which has plans for a solar thermal farm, a solar photovoltaic farm and a wind farm that are five times to 30 times bigger than the world’s current largest.

In the U.S. and elsewhere in the world, building bigger plants can be tricky.

Though economies of scale help to reduce the cost per watt of bigger projects, bigger projects are riskier to finance. Here are today’s biggest projects, from highest capacity to lowest, by type of generation.

Hydropower: Three Gorges Dam, China. Capacity: 18,000 MW. Year completed: 2008

This isn’t just the biggest renewable energy project in the world, it’s the biggest electricity-generating project, period!

It has 32 main generators. More are being added, and final capacity will be more than 20,000 MW. All that power comes at a cost: More than a million people are said to have been displaced by its construction.

Geothermal: The Geysers, Northern California, U.S. Capacity: 1,000 MW First power produced: 1921

The Geysers” aren’t actually geysers, but an underground steam reservoir nestled in mountains 70 miles north of San Francisco. The steam powers 22 power plants at the site, 15 of which are owned by Calpine. The Geysers’ steam first started producing power in 1921, but the field wasn’t developed commercially until the 1960’s.

Solar Photovoltaic, Olmedilla Photovoltaic Park , Olmedilla, Spain. 60 MW, 2008

A solar photovoltaic cell is a wonderfully elegant device. Without any moving parts it simply transforms the photons emitted from the sun into electrons that can run our lives.

The problem, however, is gathering enough photons. The world’s biggest field is just 60 MW. That’s about to change.

Several larger plants are planned, both in the U.S. and abroad.

The really big plans, of course, are Chinese. The first phase of a gargantuan project that is expected to create a 2,000-MW field of First Solar thin film panels by 2019 gets underway this summer.

Solar Thermal: Solar Energy Generating Systems, Mojave Desert, Calif., U.S. Capacity: 354 MW. Year completed: 1990

This system, known as SEGS, is a collection of nine plants that redirect the sun’s heat to tubes of synthetic oil.

The heat in the oil is transferred to water, producing steam that turns a turbine.

Bright Source Energy is planning a bigger 440 MW solar thermal project, also in the Mojave Desert.

But these plants seem quaint compared with a Chinese plan announced this month to build a series of solar thermal plants in the Mongolian desert designed by eSolar that could reach 2,000 MW.

Forbes Magazine