Montana Developer Ready to Build Modern-Day Pumped Hydro Storage

A former Navy prosecutor turned Montana-based clean energy
developer wants to build the first pumped hydro storage facility
the U.S. has seen in years.

Battery installations are growing at a steady clip, but good old
pumped hydro storage, which lifts water into elevated reservoirs
for later use in generation, still utterly dominates the field. The
21.6 gigawatts of installed pumped hydro provide 97 percent of
utility-scale storage
on the U.S. grid, according to the
National Hydropower Association.

Pumped hydro does not drive many headlines, though, because its
scale and environmental implications translate into decade-long
development cycles, and almost nobody tries any more.

Carl Borgquist, president and CEO of Absaroka Energy decided to
try, and he made that decision a decade ago.

Since then, his firm has acquired rights to build Gordon Butte,
a closed-loop system of two man-made reservoirs on private land in
Montana, 5.5 miles from the Colstrip transmission line that
shuttles renewable generation out to the utilities of the Pacific
Northwest. He applied for and obtained the various state and
federal certifications needed to build such a facility. 

In July, Absaroka announced that Danish fund manager Copenhagen
Infrastructure Partners
signed on as lead equity investor

Now, all the project needs is an offtaker — utility or
otherwise — to contract for capacity, frequency regulation,
ancillary services or whatever other function the plant can
serve.

“Everything else is really ready to go,” Borgquist told GTM.
“We just need to find the tenant for our building, so to
speak.”

If a customer materializes, the project could break ground in
2020 with an expected four-year construction timeline. Doing so
would lend credibility to the often quoted but little enacted
theory that
pumped hydro offers massive untapped potential
for storing
clean electricity.

New century, new tech

All pumped hydro projects share certain formal structures:
discrete reservoirs, difference in elevation, turbines. Absaroka’s
Gordon Butte will attempt to innovate on the form as the first new
project of its kind since the rise of wind and solar power.

For one thing, it won’t devastate any lovely riparian
ecosystems. The consideration of the environmental fallout caused
by dam construction brought the U.S. dam boom of the 20th century
to a firm halt.

Absaroka doesn’t even want to touch existing water systems, so
it will build its own. The sealed reservoirs, with roughly 60 to 80
acres of surface area, will sit across 1,000 feet of vertical
difference, like “two lined swimming pools connected by a
pipe,” Borgquist said. The project has a state-issued water right
for the life of the facility, including an initial fill, to be
followed by top-offs for the approximately 10 percent of volume
that will dissipate via evaporation each year.

The equipment producing the power got a modern update, too.

Traditionally, pumped hydro facilities used a fixed speed,
reversible turbine to pump water up for charging or let it fall
back down for discharging. Switching from one to another can take
up to half an hour, Borgquist said.

That was fine when plants only needed to switch over predictably
twice a day to store extra nuclear generation, for instance, but
it’s not competitive in the fast-paced world of a grid with ample
intermittent renewables. 

Instead, Borgquist said, this will be the first U.S. facility to
install a “quarternary” architecture that pairs a turbine with
a generator alongside a variable speed motor hooked up to a pump.
The three turbine sets can operate independently, which allows the
plant to generate and store simultaneously. The variable speed
pumping also enables much faster change-over from storing to
generating.

“The idea was to create a very flexible tool for the grid that
we’re walking into,” Borgquist said. “The grid that we’re
walking into needs that kind of speed and flexibility.”

Absaroka partnered with the National Renewable Energy Laboratory
and others on a Department of
Energy-funded study
of more flexible pumped hydro designs. Now
the company is putting that work into practice.

Bucking the trend

Projects with decade-long lead times and no recent models for
success can be a hard sell to investors. Absaroka nevertheless won
over CIP as a backer. Borgquist attributes some of that to his
team’s willingness to embrace intense regulatory vetting.

The Federal Energy Regulatory Commission has
jurisdiction over hydropower projects
that occupy navigable
waterways, sit on public land or use water from federal dams.
Gordon Butte does none of those, but the developers volunteered for
FERC scrutiny anyway; the process wrapped in relevant state
agencies to assess the project’s impacts.

“It’s a billion-dollar project and we felt like we needed
that scrutiny to attract someone like CIP,” Borgquist said.
“Now we have a record and financing parties are comfortable with
the fact that we’ve been studied.”

The capital investment and regulatory hurdles are steeper than
what lithium-ion battery developers face. Fast turnarounds have
been a key asset for those newfangled storage facilities. But
Borgquist believes pumped hydro can succeed in areas where
lithium-ion grid storage is weaker.

Pumped hydro contains no harmful chemicals, and Gordon Butte,
initially licensed for 50 years, doesn’t face the kinds of
degradation issues that lithium-ion cells suffer over time.

“We’re more complicated to permit and put in the ground, but
our first major maintenance moment is at year 27, when it’s
estimated that the turbines will need to be replaced,” Borgquist
said. “The rest of the equipment is just big valves, big pipes. It
doesn’t really change, no matter how many times you cycle
it.”

The biggest advantage, of course, is scale. A few
record-breaking lithium-ion projects are underway at the scale of
100 megawatts with four hours of duration. Some even larger ones
have been announced. Gordon Butte would offer 400 megawatts of
power capacity with more than eight hours of duration. That’s a lot
more room to store renewable generation.

A lot still has to go right before that happens. If it does,
Borgquist hopes the project can serve as a model.

“It’s not cold fusion,” he said. “We’re hoping the word
gets out there and people will copy.”

Source: FS – GreenTech Media
Montana Developer Ready to Build Modern-Day Pumped Hydro Storage