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Could Coal (Power Plant) Country be the Next Frontier for Solar Brightfields?

In August 2017, representatives from the Department of Defense, United States Air Force, United States Navy, utility Gulf Power, and Coronal Energy stood on the edge of an airport runway at NOLF Saufley Field, just west of Pensacola, FL. Yet on that hot summer morning last year at Saufley, no planes were to be seen; no takeoffs or landings were to be observed.

Originally commissioned in 1943 and previously a Naval Air Station, Saufley’s air traffic control tower closed in the 1970s. After that, it became a Naval Outlying Landing Field (NOLF) for the region’s other military installations. Even so, by 2017 planes hadn’t flown in or out of Saufley in years.

“Flip the Switch” with Ed Feo, Vice Chairman of Coronal Energy shaking hands with Michael Burrows, VP and Sr. Production Officer at Gulf Power along with several military officers. (Photo courtesy of Coronal Energy)

Erratic weeds grew up through cracks in the remnant asphalt of the old runways. A still-active radar hub sat off in a field in the distance. With such a backdrop, those DoD, Air Force, and Navy officials had gathered to commemorate and flip the switch on a new phase in Saufley’s evolution: as a utility-scale solar farm.

Part of the three-site, 120-megawattac Gulf Coast Solar Center, Saufley had become one of the latest examples of adaptive re-use of land to power the clean energy revolution. Now, in place of those stubborn weeds reclaiming the runway, rows upon rows of steel, fixed-tilt racking systems host hundreds of thousands of solar panels gleaming in the hot, midsummer Florida sun.


Airports: A Gateway to the Friendly, Sunny Skies

Saufley’s is not the story of an active airport installing ground-mounted, megawatt-scale solar in out-of-the-way parcels of airport property. That trend, too, is prevalent. Denver, Indianapolis, Tucson, Honolulu, Fresno, and Chattanooga are but a few of the growing list of U.S. airports that have been going solar.

Aerial of completed Saufley site. (Photo courtesy of Coronal Energy)

Instead, like the old airport in Halifax County, North Carolina—which became an almost-30-megawatt solar array in 2014—Saufley’s story is about a parcel of land reinventing itself after a previous use faded into obsolescence or the history books.


Adaptation: Finding a Home for Solar in a Variety of Places

Like crabgrass—and we mean this as a compliment—solar has a way of growing in all sorts of diverse and surprising places. Traditional greenfield development remains the foundation of the utility-scale solar segment, but it certainly is not the entire story.

From landfills, to brownfields, to greyfields, solar is often the transformative force turning them anew into brightfields. When all the right factors align to make such a project viable, the potential upside can be great, including giving neglected or otherwise disused land new life and new income, as at NOLF Saufley.

But as a 2016 Greentech Media headline declared, “building solar projects on brownfields is hard work.” Site remediation, tax structures and government incentives, availability of interconnection and transmission capacity, and myriad other factors all can equate to baggage that comes along with a prospective site. At a time when utility-scale solar PV is competing against (and often beating) traditional generation sources on price alone, that baggage can equate to developer headaches, higher price and risk, and ultimately an unforeseen deal breaker.


Coal (Power Plant) Country: The Next Frontier for Utility-Scale Solar?

So what might be the next big wave of siting opportunities for brightfield solar? That answer might be sitting right under our proverbial noses: coal-fired power plants.

For starters, there are likely to be many such available sites in the foreseeable future. According to the U.S. Energy Information Administration (EIA), between 2011 and the end of 2017, the U.S. retired 50 GW of coal-fired generating capacity. That same agency forecasts another 65 GW of coal power plant retirements during the period 2018–2030. These estimates are probably conservative, and actual coal plant retirements could be even greater as cheaper alternatives outcompete legacy coal.

For another, solar developers will appreciate at least two things left behind when a coal plant retires: a) a market point of interconnection and b) available and recently vacated physical transmission assets. These are critical factors in any major solar project, and coal plant retirements can essentially “check the box” for a critical element of the long utility-scale solar development checklist: a ready-made point of interconnection to the transmission grid.

And finally, solar development aligned to coal-fired power plant closings could bring economic development, construction jobs, and other benefits—including retraining local workforces for renewables jobs—to areas of the country that haven’t seen many of the direct, local benefits of the renewable energy revolution to date. Though there is some overlap in the country’s solar farm and coal plant footprints by state, generally the regions most rich in utility-scale solar farms do not overlap with those areas most dense with coal-fired power plants. That map looks more like two jigsaw puzzle pieces that, when put together, can paint a fuller picture of the nation.


A Sunny Future for Coal Plant Sites

This idea isn’t without precedent. In 2016, Ontario’s Independent Electricity System Operator announced that the Nanticoke Generating Station—previously North America’s largest coal-fired power plant which had closed three years earlier—would emerge like a Phoenix from its coal-fired ashes to become a 44 MW solar farm. Later that same year, the coal-burning Mount Tom Power Station in Massachusetts announced it would build a 6 MW solar farm on the site of its defunct power plant.

But will this idea take root and can it scale? Coal plant retirements present compelling opportunities and efficiencies yet also leave many elements of traditional utility-scale solar development on the table. And, of course, no one is pretending that a 44-MW solar farm alone can replace the shuttered generating capacity of a 3,964-MW coal-fired power plant or that a 6-MW New England solar farm can wholly substitute for a defunct 146-MW power plant.

When coal retires, a mix of resources typically including transmission, natural gas, wind, and low-cost solar is often the solution to provide resource adequacy and replacement energy in load-constrained areas. Grid operators continue to navigate a rapidly evolving market where zero-marginal-cost renewable generation dominates capacity additions. Those additions—paired with gas, demand-side management, and storage—represent a likely path forward.

Replacing North America’s retiring coal-fired power plants will require a comprehensive approach to solar development. But their points of transmission interconnection could well be the places to start. It’s an opportunity for solar generators and utility offtakers alike to together continue the shift toward a cleaner grid, bringing the coal-fired grid of yesterday and the solar-powered grid of tomorrow into closer alignment than ever before.