WEST LIBERTY – Ohio Caverns has attracted tourists for over 100 years, and with new improvements in technology has become energy neutral. Now with its own solar field and electric car charging station, Ohio Caverns is the first cave in the United States to have solar energy produced on site.
“It’s what we do. We protect the cave, we show the cave, we educate people on the cave – but we’ve been stewards of the environment since the cave first opened,” said Ohio Caverns owner Eric Evans. “It was a really good fit from an educational standpoint… Everything that is done up on the surface, believe it or not, affects the cave environment, so we were wanting to do our part when it comes to conservation. That’s where we see the future of the longevity of the cavern is protecting and preserving the environment, and this was by far the cleanest form of energy known. There’s no byproduct, we’re literally using the sun to power everything here in the park, and the cave, and the air conditioning, and lighting that we have here, is all powered by the solar array.”
Evans said that the caverns have seen the full gamut of energy usage, from the public opening in 1897 when visitors walked through with lanterns and candles, to using generators in the early 190os. Rural electric lines were not strung until 1933 when the caverns started buying electricity from Ohio Edison. They now work with Dayton Power and Light, but lighting the cave continues to be one of the greatest expenses.
“Step one, when we started this process, was we needed to really sit down and analyze what our consummations were here at the cave,” Evans said. “Our utility company, Dayton Power and Light, provides data for the previous year, so we can see kind of what our consumption was. Step number one was we went through and we did a complete LED retrofit with the cave lighting, with all the facilities, the visitors center here, the restrooms, and got our consumption down to the point that solar really became very viable.”
Evans and his team at the cave worked closely with Ohio Green Wind, of Tipp City, meeting with reps of Ohio Green Wind and DP&L multiple times. Together, they came to the conclusion that to make the caves 100 percent energy neutral they would need to produce somewhere in the range of 72 megawatt hours of electricity annually.
“We didn’t want to get carried away and overproduce, but we didn’t want to under-produce,” he said. “A lot of things go into the equation. You need to find out where you are in relation to the equator in terms of angles and the sun and some of those kinds of things, which would then help determine the size of the array. The bottom line is what we are producing out there is 44,000 watts at any given time when the sun is at its peak.”
Goal: No electric bill
Evans said that utilities had been the cave’s second largest expense after payroll, and that it made sense to address that as quickly as possible. Acknowledging that the solar array has not yet been running for a full year, he added that his goal was to have a net zero dollar expense for their electric bill, and that the program should comfortably pay for itself in six or seven years.
“We threw the switch in December 2017, but it wasn’t a good test until we were through the short days,” he said. “Dec. 21 is shortest day of sunlight, and March is when it starts ramping up … Our busy time of year at the cave is the summertime. Ninety percent of what we do occurs Memorial Day to Labor Day, so that’s when we are consuming the most electric. That’s when the air conditioners are running the most, so through the summer months we may have a small electric bill, but then through the fall, winter and spring we’ll have surpluses. You almost have to look at it not so much on a month to month, but on an annual basis.”
The current solar program requires Ohio Caverns to stay on the electric grid because there is no battery storage, an improvement they may consider in years to come.
“We do not have battery storage systems here for the solar array,” Evans said. “We utilize what’s called a net meter… we’re still hooked up to the grid, but we are either overproducing and sending electric back to the grid, or we’re consuming and we’re buying electric. So we don’t need to worry about storage simply because the net meter measures the amount of electricity that’s either going back to the grid or that we’re consuming, so in the end what you want is a situation where you have that neutrality, where you’re not overproducing and not under producing, but yet you make enough electric to provide electricity to the caverns on an annual basis.
“If we do that (add a battery) then we would have the ability to completely go off the grid, and then we would have to look a little closer at managing our electric usage,” he added. “It takes a little more than just storing the electric and using the electric, you really have to pay attention to your usage and managing those kilowatt hours of electric. As battery or storage technology improves that is something we absolutely would consider down the road.”
Ohio Caverns receives about 70,000 visitors a year and is open every day except Thanksgiving Day and Christmas Day. Two separate tours run through one mile each of underground caves, which maintain a constant temperature of 54 degrees Fahrenheit regardless of the temperature outside. For more information about Ohio Caverns, visit www.ohiocaverns.com.
