Solar plant in the desert on a sunny day.

Image source: First Solar.

The U.S. used to be the home of some of the biggest solar farms in the world, and it really pioneered the solar industry as we know it today. Modern solar cells and manufacturing techniques were developed here, and they make the solar industry as we know it possible. 

But today's solar industry is dominated by Asian companies, and countries such as India and China are making U.S. solar installations look low by comparison. And both countries have taken the title of largest solar plant, which the U.S. once proudly held. 

China and India are both finding that it's cheaper and cleaner for their countries to build solar plants than to build more coal-fired plants that have driven their economic growth for decades. Today, it's solar energy that's powering the region's economic boom, because with bids coming in below $0.03 per kWh, there's no cheaper source of new electricity generation on earth. 

Utility scale solar installation shown from the ground with the setting sun in the background.

Image source: First Solar.

550 MW Topaz Solar Farm

First Solar (FSLR -1.70%) built the 550 MW Topaz Solar Farm in San Luis Obispo County, Calif., completing construction in November 2014. According to First Solar, the electricity from the plant will power 160,000 average California homes and is the equivalent of removing 73,000 cars from the road. 

Built with thin-film solar panels, this is the only project on the list that uses non-silicon-based solar cell technology. 

Aerial view of the Solar Star project with mountains in the background.

Image source: SunPower.

579 MW Solar Star

In March 2015, SunPower's (SPWR) Solar Star project near Rosamond, Calif., was completed and, at the time, was the largest in the world at 579 MW. The project uses tracking technology that tracks the sun, meaning it gets more energy per MW than fixed solar farms, like Topaz. 

SunPower estimates there is enough electricity generated each year to power 255,000 homes and is the equivalent of removing 2 million cars from the road. 

Solar panels mounted on a flat surface in a row with a sunny sky in the background.

Image source: Getty Images.

648 MW Kamuthi Solar Power Project

In November 2016, the 648 MW Kamuthi Solar Power Project was completed in Kamuthi, India. Some 2.5 million solar panels cover an area of nearly 4 square miles. 

India is investing heavily in solar energy, with a goal of installing 100 GW, enough to power 16.4 million U.S. homes, by 2022. Projects like this are a big step in the right direction, and India will be a market leader for the foreseeable future. 

Satellite image of the Longyangxia Dam Solar Park from space.

Satellite image of the Longyangxia Dam Solar Park in early 2017. Image source: NASA.

850 MW Longyangxia Dam Solar Park

The Longyangxia Dam Solar Park is made of 4 million solar panels over a 10-square-mile site in the Qinghai province of China. And at 850 MW, it took the title of largest solar farm in the world in February 2017. 

China's western provinces are extremely arid, making them perfect for large solar farms like this one. And this won't be the biggest solar project for long. 

Utility scale solar plant with an ominous sky in the background.

Image source: Getty Images.

1,000 MW Kurnool Ultra Mega Solar Park

India shed the title of largest solar farm for a few months, but it took it back by April 28. The Kurnool Ultra Mega Solar Park is now operational with 1,000 MW, or 1 GW, of solar power generation. U.S. company SunEdison developed 500 MW of the project with Softbank Energy, Azure Power, and Andi developing the rest. 

India will build at least two more solar farms totaling 1 GW over the next few years, and unlike the U.S., these big projects seem to have a bright future. 

Utility scale solar installation in a field with trees in the background.

Image source: SunPower.

Why the U.S. is giving up its ultra-mega solar lead

The U.S. has clearly lost its lead in the "ultra-mega" solar market, leaving India and China to battle for the top spot. But that's somewhat by design. Most projects in the U.S. are now 50 MW to 200 MW, which are easier to site and incorporate into the local grid. Topaz and Solar Star required massive transmission infrastructure into the desert, which isn't as cost-effective as building near a city or town. 

As technology and new products such as energy storage become more viable, we may see the U.S. jump into the large project business again, taking advantage of the sunny, desert conditions in the southwestern United States. But for now, India holds the title of biggest solar farm and doesn't seem to want to give it up.