The world's largest solar photovoltaic power plant at a single location, India's Tamil Nadu project had yet another official unveiling and is now fully on-line and operational.  

Facts and figures on the Tamil Nadu project:

  • 648-megawatt capacity
  • Covering an area of 2,500 acres
  • Adani Group was the EPC
  • SCADA systems, automation systems and substations by ABB
  • More than 2.5 million solar modules from eight vendors including China's GCL and Italy's MegaCell
  • 27,000 tons of galvanized steel, 576 inverters, 154 transformers and 6,000 kilometers of cables
  • Robotic waterless panel cleaning by Israel's Ecoppia   
  • Connected with the 400-kilovolt substation of power distribution company Tantransco

The entire 648 megawatts were installed in a startlingly fast eight months, despite monsoons and logistical hurdles. At one point there was a total of 8,500 workers with crews installing 40,000 panels per day in three shifts -- up to 11 megawatts per day.   

Tamil Nadu's PV power station won't hold the crown for long. India's ambitious target of installing 100 gigawatts of solar power in the next five to seven years will require a lot more of these gargantuan plants.

The biggest solar projects

Some of the larger PV power plants in development, according to GTM Research, include:

  • Ukraine's four 1-gigawatt Chernobyl projects, Chinese financed, relatively likely to be built
  • Turkey's 1-gigawatt tendered project announced, very unlikely to be built
  • China's 2-gigawatt project under construction in Ningxia
  • India's three 500-megawatt projects planned in Maharashtra
  • India's 600-megawatt Odisha project planned by Sonthalia
  • Morocco's two 400-megawatt "sister" projects to be tendered in 2017

Operational U.S. solar projects include:

  • Solar Star California: SunPower, 579 megawatts
  • Topaz Solar: Built by First Solar, the 550-megawatt power plant is owned by MidAmerican Solar
  • Desert Sunlight: First Solar, 550 megawatts

In Latin America, the largest operational project is El Romero in Chile at 255 megawatts DC, which is "supplying much of its output to Google's Chilean operations," according to GTM Research.

(Check out the GTM Research Utility PV Market Tracker for much more information on utility-scale solar deployment in the U.S.)

Centralized or distributed?

If humanity is hoping to make a dent in decarbonizing its energy mix, then solar and renewables (and nuclear) have to be installed on a much bigger scale. Replacing the thousands of gigawatts of coal- and gas-burning plants on this planet might require many thousands of projects at the scale of say, the 648-megawatt Tamil Nadu PV farm or the 290-megawatt Agua Caliente PV plant.

And for China and India, it's not so much about global warming as it is about air pollution.

In any case, if the aim is to grow big and fast, it makes sense to imagine huge multi-gigawatt projects that address the scale problem head-on with really big centralized solar.

The days of big solar in the U.S., driven by state RPS goals, would seem to be over. In the U.S., huge centralized generation projects are more difficult to finance, permit and integrate into the grid compared to smaller distributed generation projects. Regulatory and political headwinds also stall giga-scale projects.

But what about China, India or North Africa? Should these regions move their capital into giga-scale projects or point capital to distributed generation and grid edge solar?

Chandra Bhushan, deputy director general of the Delhi-based nonprofit Centre for Science and Environment, responded to a recent proposed India project with a declaration for distributed generation:

"We have singularly failed in providing access to adequate, affordable and clean energy to a large section of the country’s population. As per the 2011 census, one-third of households -- about 400 million people -- do not have access to electricity. In rural India, about 45 percent of households -- more than 77 million -- continue to use kerosene to light their homes and shops. With no access to any source of lighting, 1.2 million households go dark after sunset. The country is paying huge development costs because of this energy poverty. Education, health and economic development are getting stymied."

Bhushan asked: "In such a scenario, should we invest in large and expensive solar power plants that will feed electricity into a leaking grid (the T&D loss in the country was 24 percent in 2011-12) and provide subsidized solar electricity to the rich domestic, commercial and industrial consumers? Or should we invest in small solar power plants and local (mini) grids that can provide electricity to the energy poor?"

Meanwhile, people in need of electricity are getting served by a growing roster of off-grid solar companies.