In one of the greatest ballads ever written, Kris Kristofferson* took listeners on a journey "from the coal mines of Kentucky to the California sun." Nearly five decades later, the state known for bourbon, horse racing, and coal mines is learning that "the secrets of the Sol" aren't limited to California. Here are a few places - two of them in Kentucky - that are making the transition from coal to solar.
Converting a Strip Mine to a Solar Farm
What can you do with an old strip mine after the coal has been extracted? It's not exactly prime real estate for housing, businesses, or even industrial purposes - would you build there? On the other hand, it has access to roads, power lines, and unobstructed sunshine, making it a perfect location for a solar farm. That's why an unlikely partnership between coal company Berkley Energy Group and EDF Renewable Energy is brewing. The companies are planning a solar power plant - one that could be the largest in the state - to be constructed on the site of a spent coal mine near Pikeville, Kentucky.
The project is still in the exploratory phase. While some photovoltaic farms have been installed on landfills, the unusual geography and soil composition of a strip mine could present unique challenges. Nevertheless, the companies believe that a 50 to 100-megawatt solar plant is feasible at the location. As coal mining jobs in the area disappear, company officials hope to retrain workers to contribute to the solar industry, both in the construction and maintenance of PV arrays.
Coal Mining Museum Goes Solar
Faced with budget cuts, the Kentucky Coal Mining Museum, which is owned by Southeast Kentucky Community and Technical College, turned to Bluegrass Solar to help reduce its electric bill. The company designed a rooftop photovoltaic system that will save the museum $8,000 to $10,000 in electricity costs every year.
I asked Bluegrass Solar about the technical details of the system, but so far they haven't sent any information. If they do, I'll update the article. Meanwhile, looking at the rooftop with the array still under construction, I see about 70 photovoltaic panels. Assuming they're 250W each, that's 17.5 kW. But there's more room and it's not fully installed, so it's probably bigger. Based on the anticipated savings on electricity and the half-empty rooftop (which I saw in a news video that's no longer available online), I've estimated that the building will house about a 34kW PV array. I can't think of a more appropriate, if not ironic, way to power a coal mining museum.
Coal Mine Becomes Pumped Hydro Storage Facility
Far from Kentucky, the German state of North-Rhine Westphalia is converting an abandoned coal mine into a 200 MW pumped hydropower reservoir. The energy storage facility will use excess electricity generated by solar and wind farms to pump water into the reservoir; when electrical demand exceeds the solar and wind capacity, that water will flow back down through a turbine, generating electricity. Pumped hydropower is one of the cleanest and most efficient ways to store energy, but it's only suitable in places where the local geography is appropriate. Usually, that's natural geography, but what else can you do with a man-made 600-meter hole in the ground that's filled with coal residue? Might as well power 400,000 homes with renewable energy.
Tradeoffs
Every new technology causes a shift in employment, with manual, dirty, and/or dangerous jobs (and coal mining is all three) being replaced by high-tech careers. It's easy to look back at the "good old days" and wish they'd never go away, but the reality is that coal is a technology whose time is coming to an end, for economic and environmental reasons. Rather than trade all of our tomorrows for one single yesterday, forward-thinking companies look to combine a bright economy with a clean energy future. That's good enough for me.
(*Kris Kristofferson wrote the song, but nobody sang it like Janis.)
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