(Editor’s note: Passionate about an issue, trend or product? Submit your guest post to [email protected])
By Dan Hofmann
I was reading an article recently about mountaintop removal coal mining and got to thinking …. how many square miles have been cleared in Kentucky for mountain top removal?
And, if we covered all that space with photovoltaic solar panels, how much electricity in kilowatt-hours would be produced?
Would it be enough to match the electricity consumed in Kentucky each year?
What about mountaintop removal in the U.S.?
If we covered all the square miles that have been cleared in the U.S. with photovoltaic solar panels, what percentage of the national annual kilowatt hour consumption could be provided?
I decided to crunch the numbers and what I discovered was quite intriguing:
- According to the Appalachian Voices website  (a non-profit committed to protecting the land, air and water of the central and southern Appalachian region), 574,000 acres (897 square miles) of land in Kentucky has been surface mined for coal and more than 293 mountains have been severely damaged or destroyed by mountaintop removal coal mining.
- According to the U.S. Department of Energy website , the total electricity consumption in Kentucky (residential, commercial, and industrial) in 2005 was 89.4 billion kilowatt hours.
The following projection is based on experience from photovoltaic solar installations already in place here in Kentucky and from the fact that we get four and a half hours of sunlight per day on average accounting for clouds.
To produce that much electricity in one year from solar panels in this region, around 190 square miles of land would need to be covered by a 69.1 gigawatt solar array.
And 897 square miles of land has been has been flattened by mountain top removal.
Therefore, if we merely put solar panels on one-fifth of our already cleared land, we would supply ALL of the electricity needs for the entire Commonwealth of Kentucky!
If we covered the entire 897 square miles of cleared mountaintop space in Kentucky, we could supply nearly 10 percent of the electricity needs of the entire U.S.!
Additionally, according to Appalachian Voices website , a total of 1.16 million (1,813 square miles) of land has been surface mined for coal in the central and southern Appalachian region.
According to the Central Intelligence Agency website , the United States consumed a total of 3.873 trillion kilowatt hours of electricity in 2008.
To produce that much electricity in one year from solar panels in this region, 8,225 square miles of land would need to be covered.
Accordingly, roughly 22 percent of the electricity consumed in America could be provided by photo voltaic solar panels if the 1,813 square miles of land cleared by mountain top removal in Appalachia were covered.
At this point, you’re probably saying to yourself, “That’s great, but how much would it cost? And, what about energy storage so we can use that electricity at night?”
I’ll admit that projecting the costs for a solar array of this size if pure conjecture, but I’ll do my best.
Currently, large scale, megawatt solar panel arrays cost around $3 per watt to install without tax subsidies. A gigawatt scale solar array might be closer to $2 per watt installed.
Using this metric, it would cost about $138 billion to install the 69.1 gigawatt solar array required to produce 100 percent of the electricity consumed in Kentucky per year.
If the solar panels have the industry standard 25-year warranty, the cost of electricity comes to 6.2 cents per kilowatt hour. That’s cheaper than what consumers in Kentucky pay for electricity right now (e.g. LG&E residential customers pay 7.9 cents per kilowatt hour.)
There are many options available now for grid level energy storage, including, but not limited to: pumped hydro, compressed air energy storage, sodium-sulfur batteries, lead acid batteries, nickel-cadmium batteries, flywheels and lithium ion batteries.
Empty, abandoned coal mines in Germany are being looked at for pumped hydro energy storage for renewable energy systems . Something I would assume we have plenty of in Kentucky.
Adding energy storage could cost around $1 per watt to the solar array .
This would increase the cost of the array for Kentucky to $207 billion with an electricity cost of around 9.3 cents per kilowatt hour. That price per kilowatt hour is a little more than what LG&E customers are paying right now, but will soon be on par with current rates as LG&E recently requested the Kentucky Public Service Commission to allow rates to increase by 19 percent over the next five years.
Again, the cost projection is all conjecture and does not include grid transmission and maintenance. But it’s a start.
This sounds like a lot of money until you consider that, according to a study by the Environmental Law Institute , the fossil fuel industry in the U.S. received $72 billion in subsidies from 2002 to 2008. Imagine using that money to fund a gigawatt solar project in Kentucky!
Here’s some proof that solar does work here, some public viewing of our solar installation’s real-time and historical electricity production:
About the author: Dan Hofmann is President of RegenEn Solar LLC, a solar panel installation company located in Louisville, KY.