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New Solar Farm Is A Carbon Sink & Prairie Preserver, Too

Article by Tina Casey

A movement is afoot to quash utility-scale solar development on farmland in the US, but the case for rural solar keeps expanding in new and different directions. In the latest example, Lightsource bp has built a pair of solar farms in Colorado that double as carbon sinks and help to preserve 3,000 acres of shortgrass prairie, too.

Solar developers like farmland because it is relatively flat, treeless, and exposed to sun. Roads and transmission infrastructure are pluses, too.

As for local opposition, that is a matter of local concern. However, if the objections come down to aesthetics and appropriate use of land, that is a matter of historical perspective. Farms look bucolic enough on the outside, but beneath those amber waves of grain is formerly virgin land that has been stripped of its natural state, robbed of its biodiversity, commercialized, and industrialized for generations with machines, herbicides and pesticides.

In this context, it makes sense for solar developers and their allies to advocate for solar farms as part and parcel of the regenerative agriculture movement, which prioritizes soil health and water conservation.

The basic idea is that ground-mounted solar arrays can provide farmers with income, while the soil beneath gets a rest from agricultural duties for about 25 years or more. In contrast to other forms of rural development on farms, such as new housing subdivisions or shopping malls, solar arrays are relatively temporary and the land can be farmed again, eventually.

Prairie Restoration, With Solar Power

The regenerative agriculture angle can also overlap with agrivoltaics, which refers to solar arrays that are designed to accommodate livestock grazing, pollinator habitats, and certain kinds of crops.

Another emerging area of dual-use solar farms is to restore brownfields to their natural state. One such project is happening in California, where the grounds of a decommissioned nuclear power plant are being repurposed as a prairie habitat and photovoltaic array.

Lightsource bp adopted dual-use solar farms into its business model a while back, and now that includes prairie restoration as well as agricultural activity.

The latest example is the 293-megawatt Sun Mountain Solar project in Pueblo, Colorado. A partnership between Lightsource and Xcel Energy, the solar farm went into commercial operation last week.

Lightsource used the occasion to remind everyone that it has another solar farm in Pueblo, the 300 megawatt Bighorn Solar project. Together, the two projects involve the conservation of more than 3,000 acres of shortgrass prairie in and around the solar arrays.

“Before construction began, Lightsource bp and partners designed a site-specific seed mix, suited to the local climate, ecosystem and soil,” Lightsource explains. “The mix contains staple short grasses like western wheatgrass, buffalograss and little bluestem, as well as a low concentration of purple prairie clover to provide nectar for pollinating insects.”

The prairie restoration is also expected to thwart invasive species like Cheatgrass, which has been blamed for raising the risk of wildfire.

Lightsource notes that bison and grizzly bears once roamed the area, which has since been dominated by livestock grazing. The new solar farms won’t bring back the bison and the bears, but they will push out the livestock and help protect the site for songbirds and other native species.

Solar Farms & Carbon Sequestration

Global stakeholders in the agriculture industry have already caught onto the idea that regenerative practices are good at sequestering carbon, and that can benefit the bottom line. The US Department of Agriculture is also promoting carbon sequestration as a profitable enterprise.

Solar stakeholders also seem to recognize that dual-use solar farms have a better chance of overcoming local opposition. Lightsource, for example, is among several solar developers on the advisory board of the American Solar Grazing Association, along with livestock farmers and researchers.

As described by Lightsource, carbon sequestration is a significant element in its prairie restoration model.

“Prairie habitat acts as a ‘carbon sink,’ pulling C02 underground to reduce its concentration in the atmosphere,” Lightsource explains, adding that Bighorn and Sun Mountain “will remain undisturbed for decades, allowing for many generations of shortgrass prairie plants to live and die on-site.”

“Research data indicates that over the first 25 years of the projects’ 40-year lifespan, the on-site prairie habitat will remove and store the equivalent of 36,000 tons of CO2,” Lightsource notes.

Something Is Afoot In Pueblo, Colorado

If Pueblo rings a bell, you may be thinking of the EVRAZ Rocky Mountain steel plant, which is the off-taker for the Bighorn solar farm. The facility has been ditching coal in favor of renewable energy, which is good. Not so good is the recent news about EVRAZ, which had planned on shaping the facility into a producer of new long rails for North American railways.

That was before Russian President Vladimir Putin launched his murderous rampage across Ukraine last February. Soon after, Colorado Public Radio was among the news organizations noting that EVRAZ is a Russian company.

“The EVRAZ steel mill in Pueblo is, so far, weathering economic sanctions on Russian oligarch Roman Abramovich, who owns a 28.64 percent stake of the mill’s parent company, EVRAZ plc,” CPR reported.

That was last March. Over the summer, EVRAZ announced that it is shedding Rocky Mountain and its other assets in North America.

While the company is waiting on a buyer, the Rocky Mountain makeover has run into trouble. Last month a CPR affiliate reported that a dispute between EVRAZ and one of its construction contractors broke out, leading to the layoff of more than 600 workers.

Solar Farms & The Death Of Coal

EVRAZ is reportedly transitioning to a new contractor, so hopefully it won’t be long before those new longer rails come into being. Longer rails means fewer joints, helping to reduce derailments and other potentially deadly accidents attributed to wear and tear on rail cars.

In other news about Pueblo, the Pueblo Chieftain reports that Xcel’s Commanche 3 coal power plant is on track to close, marking the end of coal for power generation in Colorado.

As part of the replacement plan, the site will host an energy storage facility for nearby solar farms.

The company behind the new facility is the up-and-coming startup Form Energy, which has come up with a new iron-air flow battery formula. As far as energy storage facilities go, this one is particularly significant because it can discharge electricity for 100 hours or more. In contrast, conventional lithium-ion batteries only discharge for four hours or so.

Form and Xcel are also partners in a similar energy storage project in Minnesota, and that’s just the tip of the iceberg. Form is setting up a new battery factory along the Ohio River in West Virginia, from which it will send coal-killing flow batteries out all across the country.

The new factory is made possible in part by financial support from the West Virginia Development Authority, which is more than a little ironic considering that West Virginia State Treasurer Riley Moore is among those leading the charge against renewable energy investment.

Whether or not Moore got the energy storage memo is an open question. Regardless, the new iron-air battery will help pump new wind and solar farm development up to 11 on the dial, thanks in part to the economic development decision makers over in West Virginia.

Photo (cropped): A new solar farm in Colorado will double as a prairie restoration project and carbon sink.

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