Coal plants, particularly the older ones most at risk of closure in the US, require significantly more labor per MWh generated than cleaner sources.
Here's a recently announced coal plant closure: http://www.cortezjournal.com/article/20161001/News05/1610099...
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the local job options could be pretty limited in far-western Montrose County once two of its major employers close their doors, eliminating what are currently 55 jobs at the plant and 28 at the mine.
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According to the EIA, the Nucla plant generated 416,150 MWh in 2015 for an annualized average power of 47.5 megawatts: http://www.eia.gov/electricity/data/browser/#/plant/527 That's an abysmal productivity per employee (or a fabulous job source, depending on your perspective): 0.86 real annualized megawatts per employee at the plant ; 0.57 megawatts per employee if you include the mining jobs.
A well-sited utility scale solar farm like Desert Sunlight can produce an average annualized power of 147 megawatts with just 15 full time employees, for a ratio of 9.8 megawatts per plant employee.
https://en.wikipedia.org/wiki/Desert_Sunlight_Solar_Farm
https://www.doi.gov/sites/doi.gov/files/migrated/news/pressr... ("Expected to create up to... 15 permanent jobs")