The company behind a proposed $1.5 billion pumped storage hydropower site outside of Craig is moving forward with the project’s development after finalizing agreements with local landowners.

Luigi Resta, president and CEO of the Salt Lake City-based company rPlus Energies LLC, said Monday that the finalization of the agreements means the company through its subsidiary, rPlus Hydro LLLP, can move forward to “start engaging with our engineering firms to actually do some pre-feasibility design and engineering at the site that will look at where the underground powerhouse is and where the shafts are.”

Resta said the company will also need to pursue a permitting process with the Federal Energy Regulatory Commission, which he hoped would be submitted by next spring, along with work needed to sign “interconnection agreements to actually secure a place to clip onto a transmission line.”

“I would like to say that we are at the finish line but we are still quite a ways before that,” Resta added.

Pumped storage hydropower technology generates power through the movement of water between two reservoirs — one placed at a higher elevation than the other — and essentially acts as a battery. When energy supply exceeds demand across the local grid, the excess power produced is diverted to the pumped hydropower site and used to move water from the lower reservoir to the upper reservoir.

“When it’s windy and sunny you might not need all that energy, and that is when you push the power uphill for when you need it at a later time,” Resta explained.

Conversely, when the grid’s supply falls short of demand, the system funnels the water down from the upper reservoir through tunnel shafts, which pass through energy producing turbines, producing energy diverted to the local grid and used to fill the gaps in supply.

Unlike other forms of renewable energy storage and producing technology, pumped hydropower storage sites stand out due to their longevity, Resta explained. The closed system can be expected to last “100 years” using technology that does not divert local water resources.

“We think that only one (of the operational sites worldwide) has actually been retired and that was one in Japan that was using salt water,” Resta said. “It is a very robust technology we are talking about.”

Today, there are 43 operational pumped storage hydropower sites in the U.S. and 150 worldwide, according to Resta. The last project to be completed in the U.S. was in 1993.

If developed, the project site in Craig would include two reservoirs expected to cover a surface area of roughly 170 acres located approximately seven miles southeast of Craig. Additionally, the site would include access roads and transmission lines, but most of the project’s development would be underground, according to a rPlus Energies spokesperson.

Local officials say the proposed hydropower storage project proposed in Moffat County is particularly important given its expected impact on a local economy bracing for a major transition.

The Tri-State Generation and Transmission Association announced in early 2020 that the Craig Station coal-fired power plant would be shutting down in 2030, along with the local Colowyo Mine that supplies it. With the looming loss of hundreds of jobs, the push to develop the pumped storage hydropower plant is part of a broad-based effort to reimagine the future of Craig and Moffat County as the area looks to transition away from a coal-based economy in the coming years.

Capable of producing 600 megawatts of power over eight hours of storage capacity, rPlus Energies expects the $1.5 billion project southeast of Craig would take five to six years to complete, with its construction projected to supply between 300 and 500 jobs.

Once operational, he added, permanent jobs would employ 35 to 40 people.

Moffat County Commissioner Tony Bohrer noted the important impact the project will have on filling part of the void left with the sunsetting of the local coal industry — both in terms of property taxes and jobs — and explained how since learning of rPlus Energies plans about two years ago, he and his fellow county commissioners have done “whatever we could” to help see the project forward.

“It’s a great thing for Moffat County,” Bohrer said of the proposed hydro-pump project. “It’s not a save-all but it’s a piece of the puzzle … We just have to keep putting this all back together.”