The Ulysses S. Grant Cottage National Historic Landmark is a preserved time capsule of the 18th president’s final days. Built in 1872 atop Mt. McGregor in eastern New York state, the cottage was where Grant wrote his final memoirs before succumbing to throat cancer. Today, the building contains many of the late president’s belongings to preserve the history of the man who led the Union army to victory in the American Civil War.
Continuing a 150-year legacy of historical preservation, the New York State Office of Parks, Recreation & Preservation installed a 30-kW off-grid solar + storage system to power the cottage and affiliated historical site facilities.
Prior to Grant’s arrival at Mt. McGregor in 1885, the site was also home to a mountaintop resort. The cottage and remaining buildings were outfitted with an early form of electricity made by a steam-powered generator. It powered lights in the hotel buildings, including the cottage.
Grant Cottage maintains that record for electrical history by being the first facility in the New York Parks network powered by an off-grid solar array.
Down the mountain from the cottage is the Mt. McGregor Correctional Facility, a former prison and tuberculosis sanitorium that was decommissioned eight years ago and has been vacant ever since. Eventually replacing the steam-powered generator was a power line that ran from the prison up the mountain to supply electricity for the cottage site, but its electrical infrastructure was degrading and the cost to repair was substantial.
In one year, the Grant Cottage experienced 12 power outages.
“This site has its inherent challenges, and those challenges increased when the prison closed,” said Ben Kemp, operations manager for the Friends of Grant Cottage. “In our perspective — both the parks department and ours — our main object must be preservation first. It has to be, because if you have nothing here — if you can’t keep the lights on, if you can’t keep the heat on — everything would degrade, and you’d have nothing to show people. There would be no historical value if things fell apart.”
The access road up to Grant Cottage is a 700-ft climb, with the actual site standing at an elevation of about 1,000 ft. So, the parks department was faced with either replacing electrical lines up the side of a mountain for a historical site that is only open 110 days a year or seeking alternative energy sources that could take the cottage off the grid, like solar and energy storage.
“We basically run May through October, and that was one of the reasons they zeroed in on this site as a candidate for an off-grid system, as opposed to many of the other parks and sites in New York,” Kemp said. “A lot of them stay open year-round and have a heavier draw on the system.”
Construction on the Grant Cottage solar project began in November 2020 and finished in April 2021. The historical site is closed to the public during that time because Mt. McGregor experiences heavy snowfall throughout the winter, making road access more difficult. Those conditions caused some construction delays as well.
The solar array was entirely constructed by a workforce of state employees from the, the Office of Parks, Recreation and Historic Preservation, the Department of Environmental Conservation and the New York State Energy Research and Development Authority. The only outside hire made for this project was a concrete contractor.
“We talked to everyone, and we asked if they were physically comfortable doing this kind of work and being out in the weather and carrying and moving stuff,” said Rodney Wiltshire, head engineer of the Grant Cottage solar project and a former employee at the New York Natural Heritage Trust. “That was basically the requirement. Then I trained every single person that was there and put them to work, and I supervised. I did some work, but I was basically running around the entire time making sure people were doing things right — and they learned.”
Wiltshire has installed PV solar since 2007, primarily through his company Empire Solar & Electric. He was contracted by the parks department to design and oversee construction on the Grant Cottage project.
For the five months of construction, state employees worked onsite building this array, enduring the natural challenges of the climate and elevation. There was constant snowfall and snowmelt conditions to contend with, as well as widely varying temperatures in the springtime when days would start with freezing temperatures and end much warmer.
Much of the ground on Mt. McGregor is full of bedrock and exposed shale. The solar array was installed atop a shale deposit along the access road before reaching the cottage. A 15-ft cliff at the edge of the shale deposit made installation conditions even trickier.
Heavy machinery like a telehandler, a forklift and a crane were brought up the mountain to hoist system equipment to the site, and an excavator was needed to dig trenches to run conduit to the site’s load center. Workers had to bring plenty of other tools up with them to get the job done too.
“We probably spent a half-hour every single day just lugging hand equipment tools up and down there,” Wiltshire said.
After the crew cleared some trees from the location, they ballasted the array with pour-in-place concrete footers set atop the shale. Piers were placed in each of the concrete blocks and IronRidge racking was attached on top of them. Boring into rock wasn’t feasible for the array’s anchors, but the state employee installers still had to drill through rock elsewhere during construction.
Conduit had to be run into another building that had granite walls that were about 20 in. thick. Installers had to bore a hole 4 in. wide for the conduit, and Wiltshire said it took five days and three broken diamond-tipped drill bits to get through the wall.
“I think that it shows that something like this, that this kind of design does have an application,” Wiltshire said. “We’re not saving the world here; we’re not providing refuge. It’s just a historical site and a visitors’ center, but this application can be used anywhere you need power that is remote, off-grid and in a location that’s very difficult to install on. And it can be done with virtually untrained but willing labor.”
The system is composed of REC 380-W modules, six OutBack Power FLEXmax 100 charge controllers, OutBack Radian 8048 inverters, MidNite Solar combiner boxes and DC disconnects and two EnerSys PowerSafe XL lead batteries, which are housed in a small storage unit next to the array.
The completed array is visible from the back porch of the cottage when leaves have fallen from the trees. Kemp said the distance of the system from the historic site was intentional to maintain an image from that period of President Grant’s life, when the lights in the cottage were still powered by steam-generated electricity.
Solar has been powering the Grant Cottage for about a year-and-a-half now. The site is expanding, and the parks department is prioritizing solar as its primary energy source with new facilities.
“It’s become a model for other parks in the state of New York, but it’s also a model for our own site,” Kemp said. “Now we immediately look at solar as the main option for the infrastructure expansion here. It’s changed the direction of the historical site.”